Cusk-eel

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Cusk-eel
Spectrunculus grandis.jpg
Pudgy cusk-eel ( Spectrunculus grandis )
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Ophidiiformes
Suborder: Ophidioidei
Family: Ophidiidae
Rafinesque, 1810
Subfamilies

See text

The cusk-eel family, Ophidiidae, is a group of marine bony fishes in the Ophidiiformes order. The scientific name is from the Greek ophis meaning "snake", and refers to their eel-like appearance. True eels diverged from other ray-finned fish during the Jurassic, while cusk-eels are part of the Percomorpha clade, along with tuna, perch, seahorses and others.

Contents

Distribution

Cusk-eels lives in temperate and tropical oceans throughout the world. They live close to the sea bottom, ranging from shallow water to the hadal zone. One species, Abyssobrotula galatheae , was recorded at the bottom of the Puerto Rico trench, making it the deepest recorded fish at 8,370 m (27,460 ft). [1] [2]

Ecology

Cusk-eels are generally very solitary in nature, but some species have been seen to associate themselves with tube worm communities. [3] Liking to be hidden when they are not foraging, they generally associate themselves within muddy bottoms, sinkholes, or larger structures that they can hide in or around, such as caves, coral crevices, or communities of bottom-dwelling invertebrates, with some parasitic species of cusk-eel actually living inside of invertebrate hosts, such as oysters, clams and sea cucumbers. [3] Cusk-eels generally feed nocturnally, preying on invertebrates, crustaceans and other small bottom-dwelling fishes.

Phylogeny

Due to the inconsistencies in specific morphological characteristics in closely related species, attempts to use different characters, such as the position of pelvic fins, to classify Ophiididae into distinct families has proven highly unsatisfactory. Overall, Ophidiidae are classified based on whether or not they practice viviparity and the structures they contain that are associated with bearing life. [3]

Characteristics

Cusk-eels are characterized by a long, slender body that is about 12–13 times as long as it is deep. The largest species, Lamprogrammus shcherbachevi , grows up to 2 m (6.6 ft) in length, but most species are shorter than 1 m (3.3 ft). Their dorsal and anal fins are typically continuous with the caudal fin (with exception to a few species), forming a long, ribbon like fin around the posterior of the cusk-eel's body. [4] This caudal fin will often be seen to be reduced to a fleshy or bony point, especially when confluent with the dorsal and anal fins. The dorsal fin to anal fin ray ratio is approximately 1.5:1, leading to the dorsal fin typically being longer than the anal. The pectoral fins of cusk-eels are typically longer than the length of their head. Unlike true eels of the order Anguilliformes, cusk-eels have ventral fins that are developed into a forked barbel-like organ below the mouth. In true eels by contrast, the ventral fins are never well-developed and usually missing entirely. [5] Cusk-eels have large mouths relative to their heads, with the upper jaw reaching beyond the eye, and paired nostrils on either side of the head. In cusk-eels, scales are potentially absent; when present, they are small. [4]

Reproduction

Unlike their close relatives, the viviparous brotulas of the family Bythitidae, cusk-eel species are egg-bearing, or oviparous, organisms. While the specifics of the eggs of the family Ophidiidae are unknown, they are believed to be either spawned as individual, free-floating eggs in the open water or are placed in a mucilaginous raft, which will float for several days until they hatch into cusk-eel larvae. These larvae live amongst the plankton relatively close to the water's surface [1] and are believed to control their metamorphoses into adult cusk-eels, dispersing over greater distances into less utilized habitats and reducing competition in concentrated areas. [3]

Conservation status

While a few species are fished commercially – most notably the pink cusk-eel, Genypterus blacodes – and several species of the order Ophidiiformes are listed as vulnerable, not enough information has been gathered about Ophidiidae as a whole to determine their conservation status.

Genera

The cusk-eel family contains about 240 species, grouped into 50 genera: [6]
Subfamily Brotulinae

Subfamily Brotulotaenilinae

Subfamily Neobythitinae

Subfamily Ophidiinae

Related Research Articles

Ophidiiformes is an order of ray-finned fish that includes the cusk-eels, pearlfishes, viviparous brotulas, and others. Members of this order have small heads and long slender bodies. They have either smooth scales or no scales, a long dorsal fin and an anal fin that typically runs into the caudal fin. They mostly come from the tropics and subtropics, and live in both freshwater and marine habitats, including abyssal depths. They have adopted a range of feeding methods and lifestyles, including parasitism. The majority are egg-laying, but some are viviparous.

<i>Abyssobrotula galatheae</i> Species of fish

Abyssobrotula galatheae is a species of cusk eel in the family Ophidiidae. It is the deepest-living fish known; one specimen, trawled from a depth of 8,370 m (27,460 ft) in the Puerto Rico Trench in 1970, holds the record for the deepest fish ever captured. Although generally recognized, some have suggested that the record-breaking individual might have been caught with a non-closing net and therefore perhaps caught shallower.

Abyssobrotula is a genus of cusk eel in the family Ophidiidae.

Bassogigas gillii is a species of cusk-eel found in the Indian, Pacific Ocean, and Atlantic Oceans at depths of from 637 to 2,239 metres.

Bassogigas is a genus of cusk eel from the subfamily Neobythitinae, part of the family Ophidiidae. The generic name "Bassogigas" comes from a combination of two Latin words: bassus, which means "deep" and gigas which means "giant". The species are found in the Indo-Pacific and western Atlantic Ocean.

Bassozetus is a genus of cusk-eels found in Atlantic, Indian and Pacific Ocean.

<i>Otophidium</i> Genus of fishes

Otophidium is a genus of cusk-eels, part of the subfamily Ophidiinae in the family Ophidiidae. They are found in the western Atlantic and eastern Pacific.

<i>Sirembo</i> Genus of fishes

Sirembo is a genus of cusk-eels of the subfamily Neobythitinae, family Ophidiidae, which are found in the Indian and Pacific Oceans. The species in this genus have a rather robust body with the dorsal fin originating over vertebrae 1–5. The head and bod are completely covered in scales, they have large eyes which are almost equal in diameter to the length of snout, the pelvic fins have two rays which are joined together within an area of tough skin, They have a short spine on the operculum which does not extend to the posterior edge of the head. Their coloration is variable but almost all species have black spots or eyespots on the dorsal fin, sometimes both, while the middle part of the anal fin frequently has a black band. The body and/or head are marked with diagonal or horizontal dark stripes or horizontal rows of quite large dusky spots.

The faceless cusk is a genus of cusk-eel found in the Indian and Pacific Oceans at depths from 3,935 to 5,100 m. This species grows to 46.5 cm (18.3 in) in standard length.

<span class="mw-page-title-main">Band cusk-eel</span> Species of fish

The band cusk-eel is a fish species in the family Ophidiidae. Widespread in the Western Atlantic from North Carolina, United States, and northern Gulf of Mexico to southeastern Brazil. Absent from The Bahamas. Marine reef-associated tropical demersal fish, up to 30 cm (12 in) long.

The striped cusk-eel is a species of fish in the family Ophidiidae. It is found in the northwest Atlantic.

Brotulotaenia brevicauda is a benthopelagic marine fish species in the family Ophidiidae. This totally black fish is usually found in the Atlantic Ocean but it has also been reported in the Indian. B. brevicauda lives in deep water and grows up to 32 cm in length. It is also occasionally known as the Short-tail cusk-eel.

<i>Brotula multibarbata</i> Species of fish

Brotula barbata, commonly known as the goatsbeard brotula, is a species of cusk-eel in the genus Brotula. It lives in the Indo-Pacific, in depths of up to 300 meters. It is dark brown with a submarginal black band and narrow white border on the dorsal and anal fins versus greenish to orange brown with orange-bordered dorsal and anal fins, and it grows up to be around 100 centimeters. It has a carnivorous diet, and it is oviparous.

<span class="mw-page-title-main">Brosmophycinae</span> Subfamily of fishes

Brosmophycinae is a subfamily of the viviparous brotulas. They are divided from the subfamily Bythitinae by having the dorsal fin, caudal fin and anal fin all separate whereas they are joined in the Bythitinae. It is divided into the tribes Dinematichthyini and Brosmophycini, with the first having hardened genital claspers and the second soft genital claspers. A review in 2016 elevated the Dinematichthyini to the status of a family the Dinematichthyidae.

<span class="mw-page-title-main">Bythitinae</span> Subfamily of fishes

Bythitinae is a subfamily of viviparous brotulas, one of the two subfamilies in the family Bythitidae. This subfamily is characterised by having the dorsal, caudal and anal fins combined. They are mostly found in temperate to tropical seas, from reefs to the benthopelagic zone, but some species from the North Atlantic Ocean occur in into Arctic waters.

<span class="mw-page-title-main">Ophidioidei</span> Suborder of fishes

Ophidioidei is one of two suborders in the order Ophidiiformes, the cusk eels, viviparous brotulas and pearlfishes. The main distinction from the suborder Bythitoidei is that the Ophidioidei are oviparous, other features include having a caudal fin which is joined to both the anal fin and the dorsal fin forming an even combined fin which tapers to a point, a lack of an external intromittent organ in males and the anterior nostril is placed high above the mouth.

<span class="mw-page-title-main">Neobythitinae</span> Subfamily of fishes

Neobythitinae is a subfamily of cusk eel from the family Ophidiidae. They are mostly fishes of deeper waters, occurring from the continental shelf down to as deep as 8,370 metres (27,460 ft) at the bottom of the Puerto Rico trench where the deepest known fish, Abyssobrotula galatheae, has been taken.

<span class="mw-page-title-main">Ophidiinae</span> Subfamily of fishes

Ophidiinae is a subfamily of the cusk eel family Ophidiidae. The species in the subfamily are characterised by having their pelvic fins situated far forward on the body and supported by a forward orientated extension of the pelvic girdle, they lack barbels on the mouth and chin and they are covered in small cycloid scales arranged in horizontal or diagonal rows. Some species have a modified swim bladder and the anterior vertebrae which enables them to generate sounds. and some of these modifications are sexually dimorphic and make the fish capable of generating sound. They have two rays in each ventral fin and the caudal fin has 9 rays. Most species are benthic and occur on the continental shelf.

<i>Lamprogrammus shcherbachevi</i> Species of Actinopterygii

Lamprogrammus shcherbachevi, the scaleline cusk, is a species of marine ray-finned fish in the family Ophidiidae.

The Pacific bearded brotula also known as the pink bearded cusk-eel or the red bearded cusk-eel is a species of cusk eel found in the Pacific Ocean. It is described as being reddish-brown with dark fins.

References

  1. 1 2 Nielsen, Jørgen G. (1998). Paxton, J.R.; Eschmeyer, W.N. (eds.). Encyclopedia of Fishes. San Diego: Academic Press. p. 134. ISBN   0-12-547665-5.
  2. ↑ "What is the deepest-living fish?". Australian Museum . 23 December 2014. Retrieved 18 September 2015.
  3. 1 2 3 4 "Ophidiiformes (Cusk-Eels and Relatives) | Encyclopedia.com". www.encyclopedia.com. Retrieved 2021-04-27.
  4. 1 2 Bigelow, Andrew (2002). Bigelow and Schroeder's fishes of the Gulf of Maine. Washington, DC: Smithsonian Institution Press.
  5. ↑ Froese, Rainer, and Daniel Pauly, eds. (2006). "Ophidiidae" in FishBase . February 2006 version.
  6. ↑ Froese, Rainer, and Daniel Pauly, eds. (2008). "Ophidiidae" in FishBase . December 2008 version.
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