![Petromyzon marinus](https://upload.wikimedia.org/wikipedia/commons/2/28/Petromyzon_marinus.jpg)
![Lamprey Larva x sect pharynx labelled](https://upload.wikimedia.org/wikipedia/commons/2/2e/Lamprey_Larva_x_sect_pharynx_labelled.png)
Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of
jawless fish
Agnatha (, Ancient Greek 'without jaws') is an infraphylum of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present ( cyclostomes) and extinct (conodonts and ostracoderms) species. Among recent animals, cyclosto ...
of the
order Petromyzontiformes , placed in the superclass
Cyclostomata
Cyclostomi, often referred to as Cyclostomata , is a group of vertebrates that comprises the living jawless fishes: the lampreys and hagfishes. Both groups have jawless mouths with horny epidermal structures that function as teeth called cer ...
. The adult lamprey may be characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
, which may mean "stone licker" ( "to lick" + "stone"), though the etymology is uncertain. ''Lamprey'' is sometimes seen for the plural form.
There are about 38 known extant species of lampreys and five known extinct species. Parasitic carnivorous species are the most well-known, and feed by boring into the flesh of other fish to
suck their blood; but only 18 species of lampreys engage in this
micropredatory lifestyle. Of the 18 carnivorous species, nine
migrate from saltwater to freshwater to breed (some of them also have freshwater populations), and nine live exclusively in freshwater. All non-carnivorous forms are freshwater species. Adults of the non-carnivorous species do not feed; they live on reserves acquired as ammocoetes (
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
...
e), which they obtain through
filter feeding
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...
.
Distribution
Lampreys live mostly in coastal and fresh waters and are found in most temperate regions. Some
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
(e.g. ''
Geotria australis
The pouched lamprey (''Geotria australis''), also known as the korokoro or wide-mouthed lamprey, is a species in the genus ''Geotria'', which is the only genus in the family Geotriidae. The second species in the genus is the Argentinian lamprey ...
'', ''
Petromyzon marinus
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish".
Description
The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ...
'', and ''
Entosphenus tridentatus
The Pacific lamprey (''Entosphenus tridentatus'') is an anadromous parasitic lamprey from the Pacific Coast of North America and Asia. It is a member of the Petromyzontidae family. The Pacific lamprey is also known as the three-tooth lamprey and ...
'') travel significant distances in the open ocean,
as evidenced by their lack of
reproductive isolation between populations. Other species are found in land-locked lakes. Their
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
...
e (ammocoetes) have a low tolerance for high water temperatures, which may explain why they are not distributed in the tropics.
Lamprey distribution may be adversely affected by overfishing and pollution. In Britain, at the time of the
Conquest
Conquest is the act of military subjugation of an enemy by force of arms.
Military history provides many examples of conquest: the Roman conquest of Britain, the Mauryan conquest of Afghanistan and of vast areas of the Indian subcontinent, t ...
, lampreys were found as far upstream in the
River Thames
The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...
as
Petersham . The reduction of pollution in the Thames and
River Wear has led to recent sightings in London and
Chester-le-Street
Chester-le-Street (), also known as Chester, is a market town and civil parish in County Durham, England, around north of Durham and also close to Sunderland and Newcastle upon Tyne. It is located on the River Wear, which runs out to sea at ...
.
Distribution of lampreys may also be adversely affected by dams and other construction projects due to disruption of migration routes and obstruction of access to spawning grounds. Conversely, the construction of artificial channels has exposed new habitats for colonisation, notably in North America where sea lampreys have become a significant introduced pest in the
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lak ...
. Active control programs to control lampreys are undergoing modifications due to concerns of drinking water quality in some areas.
Biology
Anatomy
Adults superficially resemble
eel
Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...
s in that they have
scaleless, elongated bodies, and can range from in length. Lacking
paired fins, adult lampreys have large eyes, one nostril atop the head, and seven
gill
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
pores on each side of the head.
The brain of the lamprey is divided into the
telencephalon
The cerebrum, telencephalon or endbrain is the largest part of the brain containing the cerebral cortex (of the two cerebral hemispheres), as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In ...
,
diencephalon,
midbrain
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ...
,
cerebellum, and
medulla
Medulla or Medullary may refer to:
Science
* Medulla oblongata, a part of the brain stem
* Renal medulla, a part of the kidney
* Adrenal medulla, a part of the adrenal gland
* Medulla of ovary, a stroma in the center of the ovary
* Medulla of t ...
.
The
heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
of the lamprey is anterior to the intestines. It contains the
sinus
Sinus may refer to:
Anatomy
* Sinus (anatomy), a sac or cavity in any organ or tissue
** Paranasal sinuses, air cavities in the cranial bones, especially those near the nose, including:
*** Maxillary sinus, is the largest of the paranasal sinuses, ...
, one
atrium
Atrium may refer to:
Anatomy
* Atrium (heart), an anatomical structure of the heart
* Atrium, the genital structure next to the genital aperture in the reproductive system of gastropods
* Atrium of the ventricular system of the brain
* Pulmona ...
, and one
ventricle protected by the pericardial cartilages.
The
pineal gland, a photosensitive organ regulating
melatonin production by capturing light signals through the
photoreceptor cell converting them into intercellular signals of the lamprey is located in the midline of its body, for lamprey, the
pineal eye
A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhythm ...
is accompanied by the parapineal organ.
The
buccal cavity
The buccal space (also termed the buccinator space) is a fascial space of the head and neck (sometimes also termed fascial tissue spaces or tissue spaces). It is a potential space in the cheek, and is paired on each side. The buccal space is super ...
, anterior to the
gonads, is responsible for attaching the animal, through suction, to either a stone or its prey. This then allows the tongue to make contact with the stone to rasp
algae, or tear at the flesh of their prey to yield blood.
The pharynx is subdivided; the ventral part forming a respiratory tube that is isolated from the mouth by a valve called the velum. This is an adaptation to how the adults feed, by preventing the prey's body fluids from escaping through the gills or interfering with
gas exchange
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a ...
, which takes place by pumping water in and out of the gill pouches instead of taking it in through the mouth.
One of the key physical components to the lamprey are the
intestines
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
, which are located ventral to the
notochord. Intestines aid in
osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration o ...
by intaking water from its environment and desalinating the water they intake to an
iso-osmotic state with respect to blood, and are also responsible for
digestion
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intest ...
.
Near the gills are the eyes, which are poorly developed and buried under skin in the larvae. The eyes consummate their development during metamorphosis, and are covered by a thin and transparent layer of skin that becomes opaque in preservatives.
Morphology
![Lamprey skeleton lateral view](https://upload.wikimedia.org/wikipedia/commons/c/c1/Lamprey_skeleton_lateral_view.jpg)
The unique morphological characteristics of lampreys, such as their
cartilaginous
Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck a ...
skeleton, suggest they are the sister taxon (see
cladistics
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived cha ...
) of all living jawed vertebrates (
gnathostomes
Gnathostomata (; from Greek: (') "jaw" + (') "mouth") are the jawed vertebrates. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates, including humans. In addition to opposing jaws, living ...
). They are usually considered the most basal group of the
Vertebrata
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
. Instead of true vertebrae, they have a series of cartilaginous structures called arcualia arranged above the notochord.
Hagfish
Hagfish, of the class Myxini (also known as Hyperotreti) and order Myxiniformes , are eel-shaped, slime-producing marine fish (occasionally called slime eels). They are the only known living animals that have a skull but no vertebral column, ...
, which resemble lampreys, have traditionally been considered the sister taxon of the true vertebrates (lampreys and gnathostomes)
but DNA evidence suggests that they are in fact the sister taxon of lampreys.
Studies have shown that lampreys are among the most energy-efficient swimmers. Their swimming movements generate low-pressure zones around the body, which pull rather than push their bodies through the water.
Research on sea lampreys has revealed that sexually mature males use a specialized heat-producing tissue in the form of a ridge of fat cells near the anterior dorsal fin to stimulate females. After having attracted a female with pheromones, the heat detected by the female through body contact will encourage spawning.
Due to certain peculiarities in their
adaptive immune system
The adaptive immune system, also known as the acquired immune system, is a subsystem of the immune system that is composed of specialized, systemic cells and processes that eliminate pathogens or prevent their growth. The acquired immune system ...
, the study of lampreys provides valuable insight into the evolution of vertebrate adaptive immunity. Generated from a somatic recombination of
leucine-rich repeat gene segments, lamprey leukocytes express surface
variable lymphocyte receptors (VLRs).
This convergently evolved characteristic allows them to have lymphocytes that work as the
T cell
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell r ...
s and
B cells present in higher vertebrates immune system.
Northern lampreys (Petromyzontidae) have the highest number of
chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
s (164–174) among vertebrates.
Pouched lamprey (''Geotria australis'') larvae also have a very high tolerance for free iron in their bodies, and have well-developed biochemical systems for detoxification of the large quantities of these metal ions.
Lampreys are the only extant vertebrate to have four eyes.
Most lampreys have two additional
parietal eye
A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhyth ...
s: a pineal and parapineal one (the exception is members of ''
Mordacia
''Mordacia'' is the sole genus of the family Mordaciidae, also known as the southern topeyed lampreys.
Species
There are currently three recognized species in this genus:
* ''Mordacia lapicida'' ( J. E. Gray, 1851) (Chilean lamprey)
* ''Mordacia ...
'').
Adaptations
Different species of lamprey have many shared physical characteristics. The same anatomical structure can serve different functions in the lamprey depending on whether or not it is
carnivorous. For example, non-carnivorous species use their teeth to scrape algae from rocks for food, rather than drilling into the flesh of hosts. The mouth and suction capabilities of the lamprey not only allow it to cling to a fish as a
parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
,
but provide it with limited climbing ability so that it can travel upstream and up ramps or rocks to breed.
This ability has been studied in an attempt to better understand how lampreys battle the current and move forward despite only being able to hold onto the rock at a single point.
Some scientists are also hoping to design ramps
that will optimize the lamprey's climbing ability, as lampreys are valued as food in the Northwest United States and need to travel upstream to reproduce.
The
last common ancestor
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...
of lampreys appears to have been specialized to feed on the blood and body fluids of other fish after metamorphosis. They attach their mouthparts to the target animal's body, then use three horny plates (laminae) on the tip of their piston-like tongue, one transversely and two longitudinally placed, to scrape through surface tissues until they reach body fluids. The teeth on their oral disc are primarily used to help the animal attach itself to its prey. Made of keratin and other proteins, lamprey teeth have a hollow core to give room for replacement teeth growing under the old ones. Some of the original blood-feeding forms have evolved into species that feed on both blood and flesh, and some who have become specialized to eat flesh and may even invade the internal organs of the host. Tissue feeders can also involve the teeth on the oral disc in the excision of tissue. As a result, the flesh-feeders have smaller buccal glands as they do not require the production of anticoagulant continuously and mechanisms for preventing solid material entering the branchial pouches, which could otherwise potentially clog the gills. A study of the stomach content of some lampreys has shown the remains of intestines, fins and vertebrae from their prey. Although attacks on humans do occur, they will generally not attack humans unless starved.
Carnivorous forms have given rise to the non-carnivorous species that feed on algae, and "giant" individuals amongst the otherwise small American brook lamprey have occasionally been observed, leading to the hypothesis that sometimes individual members of non-carnivorous forms return to the carnivorous lifestyle of their ancestors.
Another important lamprey adaptation is its
countershading
Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, a ...
, a form of
camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
. Similarly to many other aquatic species, most lampreys have a dark-colored back, which enables them to blend in with the ground below when seen from above by a predator. Their light-colored undersides allow them to blend in with the bright air and water above them if a predator sees them from below.
Lamprey coloration can also vary according to the region and specific environment in which the species is found. Some species can be distinguished by their unique markings – for example,
''Geotria australis'' individuals display two bluish stripes running the length of its body as an adult.
These markings can also sometimes be used to determine what stage of the life cycle the lamprey is in;
''G. australis'' individuals lose these stripes when they approach the reproductive phase and begin to travel upstream.
Another example is ''
Petromyzon marinus
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish".
Description
The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ...
'', which shifts to more of an orange color as it reaches the reproductive stage in its life cycle.
Lifecycle
![Lamprey larva labelled](https://upload.wikimedia.org/wikipedia/commons/6/65/Lamprey_larva_labelled.png)
The adults spawn in nests of sand, gravel and pebbles in clear streams. After hatching from the eggs, young larvae—called ammocoetes—will drift downstream with the current till they reach soft and fine sediment in silt beds, where they will burrow in silt, mud and detritus, taking up an existence as
filter feeders, collecting detritus, algae, and microorganisms. The eyes of the larvae are underdeveloped, but are capable of discriminating changes in illuminance. Ammocoetes can grow from to about . Many species change color during a
diurnal cycle
A diurnal cycle (or diel cycle) is any pattern that recurs every 24 hours as a result of one full rotation of the planet Earth around its axis. Earth's rotation causes surface temperature fluctuations throughout the day and night, as well as we ...
, becoming dark at day and pale at night. The skin also has
photoreceptors, light sensitive cells, most of them concentrated in the tail, which helps them to stay buried. Lampreys may spend up to eight years as ammocoetes, while species such as the
Arctic lamprey may only spend one to two years as larvae, prior to undergoing a metamorphosis which generally lasts 3–4 months, but can vary between species. While metamorphosing, they do not eat.
The rate of water moving across the ammocoetes' feeding apparatus is the lowest recorded in any suspension feeding animal, and they therefore require water rich in nutrients to fulfill their nutritional needs. While the majority of (invertebrate) suspension feeders thrive in waters containing under 1 mg suspended organic solids per litre (<1 mg/L), ammocoetes demand minimum 4 mg/L, with concentrations in their habitats having been measured up to 40 mg/L.
During metamorphosis the lamprey loses both the
gallbladder
In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although ...
and the
biliary tract, and the
endostyle turns into a
thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
gland.
Some species, including those that are not carnivorous and do not feed even following metamorphosis,
live in freshwater for their entire lifecycle, spawning and dying shortly after metamorphosing.
In contrast, many species are
anadromous and migrate to the sea,
beginning to prey on other animals while still swimming downstream after their metamorphosis provides them with eyes, teeth, and a sucking mouth.
Those that are anadromous are carnivorous, feeding on fishes or marine mammals.
Anadromous lampreys spend up to four years in the sea before migrating back to freshwater, where they spawn. Adults create nests (called
redds
Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...
) by moving rocks, and females release thousands of eggs, sometimes up to 100,000.
The male, intertwined with the female, fertilizes the eggs simultaneously. Being
semelparous
Semelparity and iteroparity are two contrasting reproductive strategies available to living organisms. A species is considered semelparous if it is characterized by a single reproductive episode before death, and iteroparous if it is characteri ...
, both adults die after the eggs are fertilized.
Classification
![Geotria australis](https://upload.wikimedia.org/wikipedia/commons/2/22/Geotria_australis.jpg)
Taxonomists place lampreys and hagfish in the subphylum
Vertebrata
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
of the
phylum Chordata, which also includes the invertebrate subphyla
Tunicata (sea-squirts) and the fish-like
Cephalochordata
A cephalochordate (from Greek: κεφαλή ''kephalé'', "head" and χορδή ''khordé'', "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called lancelets. Cephalochordates possess 5 synapomorphies, or prima ...
(
lancelet
The lancelets ( or ), also known as amphioxi (singular: amphioxus ), consist of some 30 to 35 species of "fish-like" benthic filter feeding chordates in the order Amphioxiformes. They are the modern representatives of the subphylum Cephalochord ...
s or Amphioxus). Recent molecular and morphological phylogenetic studies place lampreys and hagfish in the superclass
Agnatha
Agnatha (, Ancient Greek 'without jaws') is an infraphylum of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present (cyclostomes) and extinct (conodonts and ostracoderms) species. Among recent animals, cyclosto ...
or
Agnathostomata (both meaning without jaws). The other vertebrate superclass is
Gnathostomata
Gnathostomata (; from Greek: (') "jaw" + (') "mouth") are the jawed vertebrates. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates, including humans. In addition to opposing jaws, living ...
(jawed mouths) and includes the classes
Chondrichthyes
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. ...
(sharks),
Osteichthyes (bony fishes),
Amphibia
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbor ...
,
Reptilia
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...
,
Aves, and
Mammalia
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur o ...
.
Some researchers have classified lampreys as the sole surviving representatives of the
Linnean class Cephalaspidomorphi
Cephalaspidomorphs are a group of jawless fishes named for '' Cephalaspis'' of the osteostracans. Most biologists regard this taxon as extinct, but the name is sometimes used in the classification of lampreys, because lampreys were once thought ...
.
Cephalaspidomorpha is sometimes given as a subclass of the Cephalaspidomorphi.
Fossil evidence now suggests lampreys and cephalaspids acquired their shared characters by
convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
.
As such, many newer works, such as the fourth edition of ''
Fishes of the World'', classify lampreys in a separate group called
Hyperoartia
Hyperoartia or Petromyzontida is a disputed group of vertebrates that includes the modern lampreys and their fossil relatives. Examples of hyperoartians from early in their fossil record are '' Endeiolepis'' and '' Euphanerops'' (which possessed ...
or Petromyzontida,
but whether this is actually a
clade is disputed. Namely, it has been proposed that the non-lamprey "Hyperoartia" are in fact closer to the
jawed vertebrates.
The debate about their systematics notwithstanding, lampreys constitute a single
order Petromyzontiformes. Sometimes still seen is the alternative spelling "Petromyzoniformes", based on the argument that the
type genus
In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name.
Zoological nomenclature
According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal ...
is ''
Petromyzon
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish".
Description
The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ...
'' and not "Petromyzonta" or similar. Throughout most of the 20th century, both names were used indiscriminately, even by the same author in subsequent publications. In the mid-1970s, the
ICZN was called upon to fix one name or the other, and after much debate had to resolve the issue by voting. Thus, in 1980, the spelling with a "t" won out, and in 1981, it became official that all higher-level taxa based on ''Petromyzon'' have to start with "Petromyzont-".
The following taxonomy is based upon the treatment by FishBase as of April 2012 with phylogeny compiled by Mikko Haaramo. Within the order are 10 living genera in three families. Two of the latter are
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...
at genus level today, and in one of them a single living species is recognized (though it may be a
cryptic species complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
):
*''Geotria australis''
Gray 1851 (
Pouched lamprey)
*''Mordacia lapicida''
(Gray 1851) (
Chilean lamprey)
*''Mordacia mordax''
(Richardson 1846) (
Australian lamprey)
*''Mordacia praecox''
Potter 1968 (Non-parasitic/
Australian brook lamprey)
*''Petromyzon marinus''
Linnaeus 1758 (
Sea lamprey
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish".
Description
The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ...
)
*''Ichthyomyzon bdellium''
(Jordan 1885) (
Ohio lamprey)
*''Ichthyomyzon castaneus''
Girard 1858 (
Chestnut lamprey)
*''Ichthyomyzon fossor''
Reighard & Cummins 1916 (
Northern brook lamprey)
*''Ichthyomyzon gagei''
Hubbs & Trautman 1937 (
Southern brook lamprey)
*''Ichthyomyzon greeleyi''
Hubbs & Trautman 1937 (
Mountain brook lamprey)
*''Ichthyomyzon unicuspis''
Hubbs & Trautman 1937 (
Silver lamprey)
*''Caspiomyzon wagneri''
(Kessler 1870) Berg 1906 (
Caspian lamprey)
*''Caspiomyzon graecus''
(Renaud & Economidis 2010) (
Ionian brook lamprey)
*''Caspiomyzon hellenicus''
(Vladykov et al. 1982) (
Greek lamprey)
*''Tetrapleurodon geminis''
Álvarez 1964 (
Mexican brook lamprey)
*''Tetrapleurodon spadiceus''
(Bean 1887) (
Mexican lamprey)
*''Entosphenus folletti''
Vladykov & Kott 1976 (
Northern California brook lamprey)
*''Entosphenus lethophagus''
(Hubbs 1971) (
Pit-Klamath brook lamprey)
*''Entosphenus macrostomus''
(Beamish 1982) (
Lake lamprey
The lake lamprey, ''Entosphenus macrostomus'', also known as the Vancouver lamprey or Cowichan lamprey, a recent derivative of the Pacific lamprey, is a species of freshwater lamprey endemic to two North American lakes: Lake Cowichan and Mesachie ...
)
*''Entosphenus minimus''
(Bond & Kan 1973) (
Miller Lake lamprey
The Miller Lake lamprey (''Entosphenus minimus'') is a species of lamprey in the Petromyzontidae family endemic to the United States. Its natural habitat is the Miller Lake drainage in the state of Oregon.
This species is of special interest bec ...
)
*''Entosphenus similis''
Vladykov & Kott 1979 (
Klamath river lamprey)
*''Entosphenus tridentatus''
(Richardson 1836) (
Pacific lamprey
The Pacific lamprey (''Entosphenus tridentatus'') is an anadromous parasitic lamprey from the Pacific Coast of North America and Asia. It is a member of the Petromyzontidae family. The Pacific lamprey is also known as the three-tooth lamprey and ...
)
*''Lethenteron alaskense''
Vladykov & Kott 1978 (
Alaskan brook lamprey)
*''Lethenteron appendix''
(DeKay 1842) (
American brook lamprey)
*''Lethenteron camtschaticum''
(Tilesius 1811) (
Arctic lamprey)
*''Lethenteron kessleri''
(Anikin 1905) (
Siberian brook lamprey)
*''Lethenteron ninae''
Naseka, Tuniyev & Renaud 2009 (
Western Transcaucasian lamprey)
*''Lethenteron reissneri''
(Dybowski 1869) (
Far Eastern brook lamprey)
*''Lethenteron zanandreai''
(Vladykov 1955) (
Lombardy lamprey)
*''Eudontomyzon stankokaramani''
(Karaman 1974) (
Drin brook lamprey)
*''Eudontomyzon morii''
(Berg 1931) (
Korean lamprey)
*''Eudontomyzon danfordi''
Regan 1911 (
Carpathian brook lamprey)
*''Eudontomyzon mariae''
(Berg 1931) (
Ukrainian brook lamprey)
*''Eudontomyzon vladykovi''
(Oliva & Zanandrea 1959) (
Vladykov's lamprey
''Eudontomyzon vladykovi'', or Vladykov's lamprey, is a species of lamprey in the family Petromyzontidae. It is found in Austria, Germany, The Czech Republic, Bulgaria, Romania, Serbia, and Montenegro
)
, image_map = Europe-Mo ...
)
*''Lampetra aepyptera''
(Abbott 1860) (
Least brook lamprey
The least brook lamprey (''Lampetra aepyptera'') is a common, non-parasitic lamprey
Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes , placed in the supe ...
)
*''Lampetra alavariensis''
Mateus et al. 2013 (
Portuguese lamprey)
*''Lampetra auremensis''
Mateus et al. 2013 (
Qurem lamprey)
*''Lampetra ayresi''
(Günther 1870) (
Western river lamprey)
*''Lampetra fluviatilis''
(Linnaeus 1758) (
European river lamprey
The European river lamprey (''Lampetra fluviatilis''), also known as the river lamprey or lampern, is a species of freshwater lamprey.
Description
Adult river lampreys measure from for the sea-going forms and up to for the lake forms. The very ...
)
*''Lampetra hubbsi''
(Vladykov & Kott 1976) (
Kern brook lamprey)
*''Lampetra lanceolata''
Kux & Steiner 1972 (
Turkish brook lamprey)
*''Lampetra lusitanica''
Mateus et al. 2013 (
lusitanic lamprey)
*''Lampetra pacifica''
Vladykov 1973 (
Pacific brook lamprey)
*''Lampetra planeri''
(Bloch 1784) (
European brook lamprey
The brook lamprey (''Lampetra planeri'', also known as the European brook lamprey and the western brook lamprey) is a small European lamprey species that exclusively inhabits freshwater environments. The species is related to, but distinct from, ...
)
*''Lampetra richardsoni''
Vladykov & Follett 1965 (
Western brook lamprey)
*''Entosphenus macrostomus''
Dr. Dick Beamish 1980 (
Cowichan lake lamprey)
Lamprey and chordate synapomorphies
Synapomorphies are certain characteristics that are shared over evolutionary history. Organisms possessing a
notochord,
dorsal hollow nerve cord,
pharyngeal slit
Pharyngeal slits are filter-feeding organs found among deuterostomes. Pharyngeal slits are repeated openings that appear along the pharynx caudal to the mouth. With this position, they allow for the movement of water in the mouth and out the phary ...
s,
pituitary gland
In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...
/
endostyle, and a post anal tail during the process of their development are considered to be
Chordate
A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These fi ...
s. Lampreys contain these characteristics that define them as chordates. Lamprey anatomy is very different based on what stage of development they are in. The
notochord is derived from the
mesoderm and is one of the defining characteristics of a chordate. The notochord provides signaling and mechanical cues to help the organism when swimming. The
dorsal nerve cord is another characteristic of lampreys that defines them as chordates. During development this part of the ectoderm rolls creating a hollow tube. This is often why it is referred to as the dorsal "hollow" nerve cord. The third Chordate feature, which are the
pharyngeal slit
Pharyngeal slits are filter-feeding organs found among deuterostomes. Pharyngeal slits are repeated openings that appear along the pharynx caudal to the mouth. With this position, they allow for the movement of water in the mouth and out the phary ...
s, are openings found between the pharynx or throat. Pharyngeal slits are filter feeding organs that help the movement of water through the mouth and out of these slits when feeing. During the lamprey's larval stage they rely on filter feeding as a mechanism for obtaining their food. Once lampreys reach their adult phase they become
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...
on other fish, and these
gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In con ...
s become very important in aiding in the respiration of the organism. The final Chordate synapomorphy is the post anal tail which is a muscular tail that extends behind the anus.
Oftentimes adult
amphioxus
The lancelets ( or ), also known as amphioxi (singular: amphioxus ), consist of some 30 to 35 species of "fish-like" benthic filter feeding chordates in the order Amphioxiformes. They are the modern representatives of the subphylum Cephalochorda ...
and lamprey larvae are compared by anatomists due to their similarities. Similarities between adult amphioxus and lamprey larvae include a pharynx with pharyngeal slits, a notochord, a dorsal hollow nerve cord and a series of
somite
The somites (outdated term: primitive segments) are a set of bilaterally paired blocks of paraxial mesoderm that form in the embryonic stage of somitogenesis, along the head-to-tail axis in segmented animals. In vertebrates, somites subdivide ...
s that extend anterior to the
otic vesicle
Otic vesicle, or auditory vesicle, consists of either of the two sac-like invaginations formed and subsequently closed off during embryonic development. It is part of the neural ectoderm, which will develop into the membranous labyrinth of the in ...
.
Fossil record
![Mayomyzon](https://upload.wikimedia.org/wikipedia/commons/1/17/Mayomyzon.svg)
Lamprey
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s are rare because
cartilage fossilizes less readily than
bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...
. The first fossil lampreys were originally found in Early
Carboniferous limestones, marine sediments in North America: ''
Mayomyzon pieckoensis'' and ''
Hardistiella montanensis'', from the
Mississippian Mazon Creek
The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid- Pennsylvanian epoch of the Carboniferous period. These concreti ...
''
lagerstätte
A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These f ...
'' and the
Bear Gulch Limestone
The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often consider ...
sequence. None of the fossil lampreys found to date have been longer than , and all the Paleozoic forms have been found in marine deposits.
In the 22 June 2006 issue of ''
Nature
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...
'', Mee-mann Chang and colleagues reported on a fossil lamprey from the
Yixian Formation
The Yixian Formation (; formerly transcribed as Yihsien Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the late Barremian and early Aptian stages of the Early Cretaceous. It is known for its exq ...
of
Inner Mongolia
Inner Mongolia, officially the Inner Mongolia Autonomous Region, is an autonomous region of the People's Republic of China. Its border includes most of the length of China's border with the country of Mongolia. Inner Mongolia also accounts for a ...
. The new species, morphologically similar to Carboniferous and other forms, was given the name ''
Mesomyzon mengae'' ("
Meng Qingwen's Mesozoic lamprey").
The exceedingly well-preserved fossil showed a well-developed sucking oral disk, a relatively long branchial apparatus showing a branchial basket, seven gill pouches, gill arches, and even the impressions of gill filaments, and about 80
myomere
Myomeres are blocks of skeletal muscle tissue arranged in sequence, commonly found in aquatic chordates. Myomeres are separated from adjacent myomeres by connective fascia (myosepta) and most easily seen in larval fishes or in the olm. Myomere c ...
s of its
musculature
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle ...
. Unlike the North American fossils, its
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
was almost certainly fresh water.
Months later, a fossil lamprey even older than the Mazon Creek genera was reported from
Witteberg Group rocks near
Grahamstown
Makhanda, also known as Grahamstown, is a town of about 140,000 people in the Eastern Cape province of South Africa. It is situated about northeast of Port Elizabeth and southwest of East London. Makhanda is the largest town in the Makana ...
, in the
Eastern Cape of South Africa. Dating back 360 Million years, this species, ''
Priscomyzon riniensis'', is very similar to lampreys found today. 310 to 360 million years old fossils of P. riniensis hatchlings indicate that the ammocoete larva is a more recent evolutionary trait among the lampreys. The hatchlings, measuring 15mm in length, still had their
yolk sac
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is ...
, but were found in marine sediments and already had large eyes and a toothed suction disk.
Use in research
![Olfactory-locomotor circuitry in lampreys 1](https://upload.wikimedia.org/wikipedia/commons/a/a6/Olfactory-locomotor_circuitry_in_lampreys_1.png)
The lamprey has been extensively studied because its relatively simple brain is thought in many respects to reflect the brain structure of early vertebrate ancestors. Beginning in the 1970s,
Sten Grillner
Sten Grillner (born 14 June 1941, Stockholm) is a Swedish neurophysiologist and distinguished professor at the Karolinska Institute's Nobel Institute for Neurophysiology in Stockholm where he is the director of that institute. He is considered o ...
and his colleagues at the
Karolinska Institute
The Karolinska Institute (KI; sv, Karolinska Institutet; sometimes known as the (Royal) Caroline Institute in English) is a research-led Medical school, medical university in Solna Municipality, Solna within the Stockholm urban area of Sweden. ...
in Stockholm followed on from extensive work on the lamprey started by Carl Rovainen in the 1960s that used the lamprey as a model system to work out the fundamental principles of motor control in vertebrates starting in the spinal cord and working toward the brain.
In a series of studies by Rovainen and his student James Buchanan, the cells that formed the neural circuits within the spinal cord capable of generating the rhythmic motor patterns that underlie swimming were examined. Note that there are still missing details in the network scheme despite claims by Grillner that the network is characterised (Parker 2006, 2010). Spinal cord circuits are controlled by specific locomotor areas in the brainstem and midbrain, and these areas are in turn controlled by higher brain structures, including the basal ganglia and
tectum
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal ( alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ...
.
In a study of the lamprey tectum published in 2007, they found electrical stimulation could elicit eye movements, lateral bending movements, or swimming activity, and the type, amplitude, and direction of movement varied as a function of the location within the tectum that was stimulated. These findings were interpreted as consistent with the idea that the tectum generates goal-directed locomotion in the lamprey.
Lampreys are used as a
model organism in biomedical research, where their large reticulospinal
axon
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action p ...
s are used to investigate
synaptic transmission. The axons of lamprey are particularly large and allow for
microinjection
Microinjection is the use of a glass micropipette to inject a liquid substance at a microscopic or borderline macroscopic level. The target is often a living cell but may also include intercellular space. Microinjection is a simple mechanical pro ...
of substances for experimental manipulation.
They are also capable of full functional recovery after complete spinal cord transection. Another trait is the ability to delete several genes from their
somatic cell lineages, about 20% of their DNA, which are vital during development of the embryo, but which in humans can cause problems such as cancer later in life, after they have served their purpose. How the genes destined for deletion are targeted is not yet known.
In human culture
As food
![Spit-roasted lamprey](https://upload.wikimedia.org/wikipedia/commons/f/f1/Spit-roasted_lamprey.jpg)
Lampreys have long been used as food for humans. They were highly appreciated by the
ancient Romans
In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 ...
. During the
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...
they were
widely eaten by the upper classes throughout Europe, especially during
Lent
Lent ( la, Quadragesima, 'Fortieth') is a solemn religious observance in the liturgical calendar commemorating the 40 days Jesus spent fasting in the desert and enduring temptation by Satan, according to the Gospels of Matthew, Mark and Luke ...
, when eating meat was prohibited, due to their meaty taste and texture. King
Henry I of England is claimed to have been so fond of lampreys that he often ate them late into life and poor health against the advice of his physician concerning their richness, and is said to have died from eating "a
surfeit of lampreys". Whether or not his lamprey indulgence actually caused his death is unclear.
The pie made for the coronation of
Elizabeth II of the United Kingdom on 4 March 1953 was a
lamprey pie
Lamprey pie is a pastry dish made from sea lampreys or European river lampreys. Lampreys were a delicacy for the wealthy in medieval England and were often given as gifts to royalty as a means of seeking favour. It became tradition for the city ...
. However, after many decades, the city of Gloucester had to use
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lak ...
lampreys for her Diamond Jubilee in 2012 because few lampreys could be found in the
River Severn
, name_etymology =
, image = SevernFromCastleCB.JPG
, image_size = 288
, image_caption = The river seen from Shrewsbury Castle
, map = RiverSevernMap.jpg
, map_size = 288
, map_c ...
.
In southwestern Europe (
Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
,
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
, and
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
),
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
and in
Latvia (where lamprey is routinely sold in supermarkets), lampreys are a highly prized
delicacy
A delicacy is usually a rare and expensive food item that is considered highly desirable, sophisticated, or peculiarly distinctive within a given culture. Irrespective of local preferences, such a label is typically pervasive throughout a r ...
. In Finland (county of Nakkila), and Latvia (
Carnikava Municipality), the river lamprey is the local symbol, found on their coats of arms. In 2015 the lamprey from Carnikava was included in the
Protected designation of origin list by the
European Commission
The European Commission (EC) is the executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body ...
.
Sea lamprey
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish".
Description
The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ...
is the most sought-after species in
Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
and one of only two that can legally bear the commercial name "lamprey" (''lampreia''): the other one being ''Lampetra fluviatilis'', the
European river lamprey
The European river lamprey (''Lampetra fluviatilis''), also known as the river lamprey or lampern, is a species of freshwater lamprey.
Description
Adult river lampreys measure from for the sea-going forms and up to for the lake forms. The very ...
, both according to Portaria (Government regulation no. 587/2006, from 22 June). "Arroz de lampreia" or lamprey rice is one of the most important dishes in
Portuguese cuisine
The oldest known book on Portuguese cuisine, entitled ''Livro de Cozinha da Infanta D. Maria de Portugal'', from the 16th century, describes many popular dishes of meat, fish, poultry and others.
''Culinária Portuguesa'', by António-Maria De O ...
.
![Nakkila](https://upload.wikimedia.org/wikipedia/commons/7/79/Nakkila.vaakuna.svg)
Lampreys are also consumed in
Sweden,
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
,
Lithuania,
Estonia
Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, a ...
,
Japan, and
South Korea
South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and sharing a land border with North Korea. Its western border is formed by the Yellow Sea, while its eas ...
. In Finland, they are commonly eaten grilled or smoked, but also
pickled
Pickling is the process of preserving or extending the shelf life of food by either anaerobic fermentation in brine or immersion in vinegar. The pickling procedure typically affects the food's texture and flavor. The resulting food is called ...
, or in vinegar.
The
mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...
and
serum of several lamprey species, including the
Caspian lamprey (''Caspiomyzon wagneri''), river lampreys (''Lampetra fluviatilis'' and ''L. planeri''), and sea lamprey (''Petromyzon marinus''), are known to be toxic, and require thorough cleaning before cooking and consumption.
In
Britain
Britain most often refers to:
* The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands
* Great Britain, the largest island in the United King ...
, lampreys are commonly used as
bait, normally as dead bait.
Northern pike
The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus ''Esox'' (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a p ...
,
perch
Perch is a common name for fish of the genus ''Perca'', freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Per ...
, and
chub all can be caught on lampreys. Frozen lampreys can be bought from most bait and
tackle shops.
As pests
![Sea Lamprey fish](https://upload.wikimedia.org/wikipedia/commons/4/41/Sea_Lamprey_fish.jpg)
Sea lampreys have become a major
pest in the North American
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lak ...
. It is generally believed that they gained access to the lakes via
canals
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow un ...
during the early 20th century,
but this theory is controversial.
[
]
They are considered an
invasive species, have no natural enemies in the lakes, and prey on many species of commercial value, such as
lake trout
The lake trout (''Salvelinus namaycush'') is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, namaycush, lake char (or charr), touladi, togue, and grey trout. In Lake Superior, it can also ...
.
Lampreys are now found mostly in the streams that feed the lakes, and controlled with special barriers to prevent the upstream movement of adults, or by the application of toxicants called
lampricide
A lampricide is any chemical designed to target the larvae of lampreys in river systems before they develop into parasitic adults. One lampricide is used in the headwaters of Lake Champlain and the Great Lakes to control the sea lamprey (''Petromyz ...
s, which are harmless to most other aquatic species; however, these programs are complicated and expensive, and do not eradicate the lampreys from the lakes, but merely keep them in check.
New programs are being developed, including the use of chemically
sterilized male lampreys in a method akin to the
sterile insect technique
The sterile insect technique (SIT) is a method of biological insect control, whereby overwhelming numbers of sterile insects are released into the wild. The released insects are preferably male, as this is more cost-effective and the females ma ...
.
Finally,
pheromones
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
critical to lamprey migratory behaviour have been isolated, their
chemical structure
A chemical structure determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid. Molecular geometry refers to the spatial arrangement of ...
s determined, and their impact on lamprey behaviour studied, in the laboratory and in the wild, and active efforts are underway to chemically source and to address regulatory considerations that might allow this strategy to proceed.
Control of sea lampreys in the Great Lakes is conducted by the
U.S. Fish and Wildlife Service
The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...
and the
Canadian Department of Fisheries and Oceans, and is coordinated by the
Great Lakes Fishery Commission
The Great Lakes Fishery Commission is a bi-national commission made up of representatives of the United States and Canada. It was formed by the Convention on Great Lakes Fisheries, concluded in 1954 and ratified in 1955. It has eight members: fou ...
.
Lake Champlain
Lake Champlain ( ; french: Lac Champlain) is a natural freshwater lake in North America. It mostly lies between the US states of New York and Vermont, but also extends north into the Canada, Canadian province of Quebec.
The New York portion of t ...
, bordered by
New York,
Vermont
Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...
, and
Quebec
Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...
, and New York's
Finger Lakes
The Finger Lakes are a group of eleven long, narrow, roughly north–south lakes located south of Lake Ontario in an area called the ''Finger Lakes region'' in New York, in the United States. This region straddles the northern and transitional ...
are also home to high populations of sea lampreys that warrant control.
Lake Champlain's lamprey control program is managed by the
New York State Department of Environmental Conservation, the Vermont Department of Fish and Wildlife, and the U.S. Fish and Wildlife Service.
New York's Finger Lakes sea lamprey control program is managed solely by the New York State Department of Environmental Conservation.
In folklore
In folklore, lampreys are called "nine-eyed eels". The name is derived from the seven external gill slits that, along with one nostril and one eye, line each side of a lamprey's head section. Likewise, the German word for lamprey is ''Neunauge'', which means "nine-eye", and in Japanese they are called ''yatsume-unagi'' (八つ目鰻, "eight-eyed eels"), which excludes the nostril from the count. In British folklore, the monster known as the
Lambton Worm
The Lambton Worm is a legend from County Durham in north-east England in the United Kingdom. The story takes place around the River Wear, and is one of the area's most famous pieces of folklore, having been adapted from written and oral tradit ...
may have been based on a lamprey, since it is described as an eel-like creature with nine eyes.
In literature
Vedius Pollio kept a pool of lampreys into which
slaves who incurred his displeasure would be thrown as food. On one occasion, Vedius was punished by
Augustus
Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian, was the first Roman emperor; he reigned from 27 BC until his death in AD 14. He is known for being the founder of the Roman Pr ...
for attempting to do so in his presence:
This incident was incorporated into the plot of the 2003 novel ''Pompeii'' by Robert Harris in the incident of Ampliatus feeding a slave to his lampreys.
Lucius Licinius Crassus
Lucius Licinius Crassus (140–91 BC) was a Roman orator and statesman. He was considered the greatest orator of his day, most notably by his pupil Cicero. Crassus is also famous as one of the main characters in Cicero's work '' De Oratore'', a d ...
was mocked by
Gnaeus Domitius Ahenobarbus (cos. 54 BC) for weeping over the death of his pet lamprey:
This story is also found in Aelian (Various Histories VII, 4) and Macrobius (Saturnalia III.15.3). It is included by
Hugo von Hofmannsthal
Hugo Laurenz August Hofmann von Hofmannsthal (; 1 February 1874 – 15 July 1929) was an Austrian novelist, librettist, poet, dramatist, narrator, and essayist.
Early life
Hofmannsthal was born in Landstraße, Vienna, the son of an upper-cl ...
in the
Chandos Letter:
In
George R. R. Martin
George Raymond Richard Martin (born George Raymond Martin; September 20, 1948), also known as GRRM, is an American novelist, screenwriter, television producer and short story writer. He is the author of the series of epic fantasy novels ''A Song ...
's novel series, ''
A Song of Ice and Fire'', Lord Wyman Manderly is mockingly called "Lord Lamprey" by his enemies in reference to his rumored affinity to lamprey pie and his striking
obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's ...
.
Kurt Vonnegut
Kurt Vonnegut Jr. (November 11, 1922 – April 11, 2007) was an American writer known for his satirical and darkly humorous novels. In a career spanning over 50 years, he published fourteen novels, three short-story collections, five plays, and ...
, in his late short story "
The Big Space Fuck", posits a future America so heavily polluted – "Everything had turned to shit and beer cans", in his words – that the Great Lakes have been infested with a species of massive, man-eating ambulatory lampreys.
In television
In season 3, episode 5 of “The Borgias”, whilst out on a hunting trip, Cesare Borgia’s mercenary, Micheletto, kills the King of Naples by pushing him into a pool filled with lampreys that King Firante had built during his reign of Naples.
References
Further reading
General
* Renaud, C.B. (2011) ''Lampreys of the world. An annotated and illustrated catalogue of lamprey species known to date'' FAO Species Catalogue for Fishery Purposes. No. 5. Rome. .
Research on pheromones for pest control
* , se
Mixture of new sulfated steroids functions as a migratory pheromone in the sea lamprey accessed 1 July 2015.
rimary source example.* , se
Chemical cues for sea lamprey migration accessed 1 July 2015.
ay summary of Sorensen, et al. (2005)*
rimary source example.* Richard Black, 2009, "Sex smell lures 'vampire' to doom," ''BBC News'' (online), 20 January 2009, se
Sex smell lures 'vampire' to doom accessed 1 July 2015.
ay summary of Johnson, et al. (2009); Subtitle: "A synthetic 'chemical sex smell' could help rid North America's Great Lakes of a devastating pest, scientists say."
External links
*
*
*
Long-accepted theory of vertebrate origin upended by fossilized lamprey larvae* A Tree of Life diagram showing the relation of Lampreys to other organisms.
{{Authority control
.
Hematophages
Parasitic vertebrates
Devonian fish
Extant Late Devonian first appearances
Fish described in 1940