The silverfish (''Lepisma saccharinum'') is a species of small,
primitive, wingless
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
in the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
Zygentoma
Zygentoma are an order in the class Insecta, and consist of about 550 known species. The Zygentoma include the so-called silverfish or fishmoths, and the firebrats. A conspicuous feature of the order are the three long caudal filaments. The tw ...
(formerly
Thysanura). Its
common name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...
derives from the insect's silvery light grey colour, combined with the fish-like appearance of its movements. The
scientific name (''L. saccharinum'') indicates that the silverfish's diet consists of
carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may o ...
s such as
sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or do ...
or
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human die ...
es. While the common name ''silverfish'' is used throughout the global literature to refer to various species of Zygentoma, the
Entomological Society of America restricts use of the term solely for ''Lepisma saccharinum''.
Description
The silverfish is a
nocturnal insect typically long.
Its abdomen tapers at the end, giving it a fish-like appearance.
The newly hatched are whitish, but develop a greyish hue and metallic shine as they get older.
It has two long
cerci and one terminal filament at the tip of the
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...
between the cerci. It also has two small
compound eyes, although other members of
Zygentoma
Zygentoma are an order in the class Insecta, and consist of about 550 known species. The Zygentoma include the so-called silverfish or fishmoths, and the firebrats. A conspicuous feature of the order are the three long caudal filaments. The tw ...
are completely eyeless, such as the family
Nicoletiidae.
Like other species in
Apterygota, the silverfish is completely wingless.
It has long
antennae, and moves in a wiggling motion that resembles the movement of a
fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
.
This, coupled with its appearance and silvery scales, inspires its common name. Silverfish can regenerate terminal filaments and antennae, if lost, in two to four weeks. Silverfish typically live for up to three years.
The silverfish is an agile runner. It avoids light.
Distribution
Silverfish are a
cosmopolitan
Cosmopolitan may refer to:
Food and drink
* Cosmopolitan (cocktail), also known as a "Cosmo"
History
* Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953
Hotels and resorts
* Cosmopoli ...
species, found in
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, the
Americas
The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North America, North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. ...
,
Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
,
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelag ...
, and parts of the
Pacific.
They inhabit moist areas, requiring a
relative humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
Humidity dep ...
between 75% and 95%. In
urban area
An urban area, built-up area or urban agglomeration is a human settlement with a high population density and infrastructure of built environment. Urban areas are created through urbanization and are categorized by urban morphology as cities ...
s, they can be found in attics, basements, bathtubs, sinks, kitchens, old books, classrooms, and showers.
Reproduction and life cycle
Before silverfish reproduce, they carry out a ritual involving three phases, which may last over half an hour. In the first phase, the male and female stand face to face, their vibrating antennae touching, then repeatedly back off and return to this position. In the second phase, the male runs away and the female chases him. In the third phase, the male and female stand side by side and head to tail, with the male vibrating his tail against the female. Finally, the male lays a
spermatophore
A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophore ...
, a sperm capsule covered in
gossamer
Gossamer most commonly refers to:
* Fine spider silk used by spiderlings for ballooning or kiting
* Gossamer (fabric), very light, sheer, gauze-like fabric
Gossamer may also refer to:
Technology
* Gossamer Condor, the first human-powered ai ...
, which the female takes into her body via her
ovipositor to fertilize her eggs. The female lays groups of fewer than 60 eggs at once, deposited in small crevices.
The eggs are oval-shaped, whitish, about long,
and take between two weeks and two months to hatch. A silverfish usually lays fewer than 100 eggs in her lifetime.
When the
nymphs hatch, they are whitish in colour, and look like smaller adults. As they
moult, young silverfish develop a greyish appearance and a metallic shine, eventually becoming adults after three months to three years.
They may go through 17 to 66 moults in their lifetimes, sometimes 30 in a single year—many more than most insects. Silverfish are among the few types of insect that continue to moult after reaching adulthood.
Ecology
Silverfish are able to digest
cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wa ...
by themselves, thanks to the
cellulase
Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccha ...
that is produced by their midgut.
They consume matter that contains
polysaccharides, such as
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human die ...
es and
dextrin in
adhesives.
These include book bindings,
carpet
A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester ...
,
clothing
Clothing (also known as clothes, apparel, and attire) are items worn on the body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin sheets of materials and natura ...
,
coffee
Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world.
Seeds of ...
,
dandruff
Dandruff is a skin condition that mainly affects the scalp. Symptoms include flaking and sometimes mild itchiness. It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin ...
,
glue,
hair, some
paints,
paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distribu ...
,
photo
A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now crea ...
s, plaster, and
sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or do ...
. They will damage wallpaper in order to consume the paste. Silverfish can also cause damage to
tapestries. Other substances they may eat include
cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...
, dead
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
s,
linen,
silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from th ...
, leftover crumbs, or even their own
exuviae (
moulted
exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton ( endoskeleton) in for example, a human. In usage, some of the ...
). During famine, a silverfish may even consume
leather
Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hog ...
and synthetic fabrics. Silverfish can live for a year or more without eating if water is available.
Silverfish are considered household
pests
PESTS was an anonymous American activist group formed in 1986 to critique racism, tokenism, and exclusion in the art world. PESTS produced newsletters, posters, and other print material highlighting examples of discrimination in gallery represent ...
, due to their consumption and destruction of property.
However, although they are responsible for the contamination of food and other types of damage, they do not transmit disease.
Earwigs,
house centipedes, and
spider
Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...
s such as the spitting spider ''
Scytodes thoracica
''Scytodes thoracica'' is a spitting spider, so called because it spits a venomous sticky silken substance over its prey. Its size ranges between . The carapace is unusual in sloping upwards towards its rear end, whereas the abdomen slopes downwar ...
'' are known to be
predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill t ...
s of silverfish.
The
essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
of the Japanese cedar ''
Cryptomeria japonica'' has been investigated as a
repellent and
insecticide against ''L. saccharinum'', with promising results: filter paper impregnated with a concentration of 0.01 mg/cm of essential oil repelled 80% of silverfish, and an exposure to vapours of 0.16 mg/cm for 10 hours caused a 100% mortality rate.
Etymology and nomenclature
The scientific name for the species is ''Lepisma saccharinum'' (originally ''saccharina''; Linnaeus' 1758 descriptio
here, due to its tendency to eat
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human die ...
y foods high in carbohydrates and protein, such as
dextrin.
However, the insect's more common name comes from its distinctive metallic appearance and fish-like shape. While the scientific name was established by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...
in his 1758
10th edition of ''Systema Naturae'', the common name has been in use since at least 1855.
Most authors have historically treated the nomenclatural gender of ''Lepisma'' as feminine (also as specified in ICZN Direction 71 issued in 1957), but in 2018 the
International Commission on Zoological Nomenclature issued a formal ruling (ICZN Opinion 2427) stating the gender of ''Lepisma'' (and all genera with that ending) is neuter, following ICZN Article 30, which resulted in changes to the spelling of several well-known species, including ''Lepisma saccharinum''.
Evolution
The predecessors of silverfish, along with those of
jumping bristletails, are considered the earliest and most
primitive insects. They evolved at the latest in mid-
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wh ...
and possibly as early as late
Silurian more than 400 million years ago.
Some fossilized
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...
trackways from the
Paleozoic Era, known as ''Stiaria intermedia'' and often attributed to jumping bristletails, may have been produced by silverfish.
Similar species
Other similar insect species are also known as silverfish. Two other silverfish are common in North America, ''
Ctenolepisma longicaudatum
''Ctenolepisma longicaudatum'', generally known as the gray silverfish, long-tailed silverfish or paper silverfish, is a species of Zygentoma in the family Lepismatidae. It was described by the German entomologist Karl Leopold Escherich in 190 ...
'' and ''
Ctenolepisma quadriseriatum''.
''
Ctenolepisma urbanum'' is known as the urban silverfish.
The
Australian species most commonly referred to as silverfish is a different lepismatid, ''
Acrotelsella devriesiana''.
The
firebrat
The firebrat (''Thermobia domestica'') is a small hexapod (typically 1–1.5 cm), in the order Zygentoma.
Habitat
Firebrats prefer higher temperatures and require some humidity, and can be found in bakeries and near boilers or fur ...
(''Thermobia domestica'') is like a silverfish, but with a mottled gray and brown body.
References
External links
Fact sheet on silverfish highlighting habits, habitat and threats*
Museumpests.net Silverfish factsheet{{Authority control
Lepismatidae
Household pest insects
Paleozoic insects
Mesozoic insects
Cenozoic insects
Extant Pennsylvanian first appearances
Paleozoic insects of Asia
Paleozoic insects of North America
Insects described in 1758
Taxa named by Carl Linnaeus