Grenadiers or rattails are generally large, brown to black

gadiform Gadiformes are an order of ray-finned fish, also called the Anacanthini, that includes the cod. Many major food fish are in this order. They are found in marine waters throughout the world and the vast majority of the species are found in temper ...

marine

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

of the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Macrourinae, the largest subfamily of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Macrouridae Macrouridae is a family of deep sea fish, a diverse and ecologically important group, which are part of the order of cod-like fish, the Gadiformes. The species in the Macrouridae are characterised by their large heads which normally have a singl ...

. Found at great depths from the

Arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...

, members of this subfamily are amongst the most abundant of the deep-sea fish. The macrourins form a large and diverse family with 28 extant genera recognized (well over half of the total

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 ...

are contained in just three genera, '' Coelorinchus'', '' Coryphaenoides'', and '' Nezumia''). They range in length from about in ''Hymenogadus gracilis'' to in ''Albatrossia pectoralis''. Several attempts have been made to establish a commercial fishery for the most common larger species, such as the

giant grenadier ''Albatrossia pectoralis'', the giant grenadier or giant rattail, is a very large rattail, and the only member of the genus ''Albatrossia''. It is found in the north Pacific from northern Japan to the Okhotsk and Bering Seas, east to the Gulf of ...

, but the fish is considered unpalatable, and attempts thus far have proven unsuccessful. The subfamily as a whole may represent up to 15% of the deep-sea fish population. Rattails, characterized by large heads with large mouths and eyes, have slender bodies that taper very much to very thin caudal peduncles or tails (except for one species without a caudal fin): this rat-like tail explains the common name "rattail" and the name of the subfamily and the surname are derived from the Greek makros meaning "big" and Oura meaning "tail". The first dorsal flat is small, tall and pointed (and may have rays modified into spines); The second dorsal fin runs along the rest of the back and connects to the tail and the large anal fin. The scales are small. As with many deep-living fish, the

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

system in grenadiers is well-developed; it is further aided by numerous

chemoreceptor A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance (endogenous or induced) to generate a biological signal. This signal may be in the form of an action potential, if the chemorecept ...

s located on the head and lips and chemosensory

barbel Barbel may refer to: *Barbel (anatomy), a whisker-like organ near the mouth found in some fish (notably catfish, loaches and cyprinids) and turtles *Barbel (fish), a common name for certain species of fish **''Barbus barbus'', a species of cyprinid ...

s underneath the chin.

Benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

species have

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...

s with unique muscles attached to them. The animals are thought to use these muscles to "strum" their bladders and produce sound, possibly playing a role in courtship and mate location. Light-producing organs,

photophore A photophore is a glandular organ that appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors, ...

s, are present in some species; they are located in the middle of the abdomen, just before the anus and underneath the skin. Grenadiers have been recorded from depths of about , and are among the most common benthic fish of the deep (however, two genera are known to prefer the midwater). They may be solitary or may form large schools, as with the roundnose grenadiers. The benthic species are attracted to structural oases, such as

hydrothermal vent A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

cold seep A cold seep (sometimes called a cold vent) is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs, often in the form of a brine pool. ''Cold'' does not mean that the temperature of the see ...

s, and shipwrecks. They are thought to be generalists, feeding on smaller fish, pelagic crustaceans such as

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

cumacea Cumacea is an order of small marine crustaceans of the superorder Peracarida, occasionally called hooded shrimp or comma shrimp. Their unique appearance and uniform body plan makes them easy to distinguish from other crustaceans. They live in so ...

ns, and less often

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s and

lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represent ...

. As well as being important apex predators in the benthic habitat, some species are also notable as scavengers. As few rattail

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. The ...

e have been recovered, little is known of their life histories. They are known to produce a large number (over 100,000) of tiny ( in diameter) eggs made buoyant by

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

droplets. The eggs are presumed to float up to the

thermocline A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) in which temperature changes more drastically with ...

(the interface between warmer surface waters and cold, deeper waters) where they develop. The juveniles remain in shallower waters, gradually migrating to greater depths with age. Spawning may or may not be tied to the seasons, depending on the species. At least one species, ''

Coryphaenoides armatus The abyssal grenadier, ''Coryphaenoides armatus'', is an abyssal fish of the genus ''Coryphaenoides'', found in all the world's oceans, at depths between . Its adult length is , although Fishbase gives lengths up to . The abyssal grenadier's bod ...

'', is thought to be

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 ...

; that is, the adults die after spawning. Nonsemelparous species may live to 56 years or more. The macrourins, in general, are thought to have low resilience; commercially exploited species may be overfished and this could soon lead to a collapse of their fisheries.

Genera

Currently 28 extant genera in this subfamily are recognized:Iwamoto, T., Nakayama, N., Shao, K.-T. & Ho, H.-C. (2015): Synopsis of the Grenadier Fishes (Gadiformes; Teleostei) of Taiwan. ''Proceedings of the California Academy of Sciences, 62 (3): 31-126.'' * ''

Albatrossia ''Albatrossia pectoralis'', the giant grenadier or giant rattail, is a very large rattail, and the only member of the genus ''Albatrossia''. It is found in the north Pacific from northern Japan to the Okhotsk and Bering Seas, east to the Gulf ...

'' Jordan & Gilbert, 1898 * '' Asthenomacrurus'' Sazonov & Shcherbachev, 1982 * '' Cetonurichthys'' Sazonov & Shcherbachev, 1982 * '' Cetonurus'' Günther, 1887 * '' Coelorinchus'' Giorna, 1809 * '' Coryphaenoides'' Gunnerus, 1765 * '' Cynomacrurus'' Dollo, 1909 * ''

Echinomacrurus ''Echinomacrurus'' is a genus of rattails. Species There are currently two recognized species in this genus: * ''Echinomacrurus mollis'' Louis Roule, Roule, 1916 * ''Echinomacrurus occidentalis'' Tomio Iwamoto, Iwamoto, 1979 References

...

'' Roule, 1916 * '' Haplomacrourus'' Trunov, 1980 * '' Hymenocephalus'' Giglioli, 1884 * '' Hymenogadus'' Gilbert & Hubbs, 1920 * ''

Kumba Kumba is a metropolitan city in the Meme department, Southwest Region, Western Cameroon, referred as "K-town" in local slang. Kumba is the most developed and largest city in the Meme Department and has attracted people from the local villag ...

'' Marshall, 1973 * '' Kuronezumia'' Iwamoto, 1974 * '' Lepidorhynchus'' Richardson, 1846 * '' Lucigadus'' Gilbert & Hubbs, 1920 * ''

Macrosmia ''Macrosmia phalacra'' is a species of rattail known from the Ninety East Ridge in the Indian Ocean. This fish is found at depths of from . References

* Macrouridae Monotypic fish genera Fish of the Indian Ocean Fish described in 1983 ...

'' Merrett, Sazonov & Shcherbachev, 1983 * '' Macrourus'' Bloch, 1786 * '' Malacocephalus'' Günther, 1862 * '' Mataeocephalus'' Berg, 1898 * '' Mesovagus'' Nakayama & Endo, 2016 Nakayama, N. & Endo, H. (2016): ''Mesovagus'', a replacement name for the grenadier genus ''Mesobius'' Hubbs and Iwamoto 1977 (Actinopterygii: Gadiformes: Macrouridae), a junior homonym of ''Mesobius'' Chamberlin 1951 (Chilopoda: Lithobiomorpha: Lithobiidae). ''Ichthyological Research, 64 (1): 120–122.'' * '' Nezumia'' Jordan, 1904 * '' Odontomacrurus'' Norman, 1939 * '' Paracetonurus'' Marshall, 1973 * '' Pseudocetonurus'' Sazonov & Shcherbachev, 1982 * '' Pseudonezumia'' Okamura, 1970 * '' Sphagemacrurus'' Fowler, 1925 * '' Spicomacrurus'' Okamura, 1970 * '' Trachonurus'' Günther, 1887 * '' Ventrifossa'' Gilbert & Hubbs, 1920

References

{{Taxonbar, from=Q1883040 Macrouridae Taxa named by Charles Lucien Bonaparte

Genera

See also

References