''Trachyrincus scabrus'', the roughsnout grenadier or Mediterranean longsnout grenadier, is a species of

bathydemersal Demersal fish, also known as groundfish, live and feed on or near the bottom of ocean, seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 T ...

marine fish from 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 botanical subfamily names with "-oideae", and zo ...

Trachyrincinae Trachyrincinae is a subfamily of the family Macrouridae, also known as rattails. The subfamily contains two genera found in Atlantic, Indian and Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the o ...

, part of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 sing ...

. It is found in the eastern Atlantic Ocean and the Mediterranean.

Description

''Trachyrincus scabrus'' has a large head which measures a quarter to a thirds of the length of the body and which has along, pointed snout with a ridge on side which extends posteriorly to the operculum, The mouth lies beneath the snout and the large eye has a diameter of 24-29% of the head length. The anterior dorsal fin has 11-12 fin rays, the posterior begins just behind the anterior and is much longer than the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

. The

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

has 20-22 fin rays and the pelvic fin has 7 fin rays, although it may infrequently it has 6. It has spiny scales which are enlarged along dorsal and ventral profiles, 23-42 such scales sit dorsally behind a vertical line from the anus, but there are none ventrally before the anus. They are greyish-brown in colour. It grows to over 50 cm in total length.

Distribution

The roughsnout grenadier occurs in the eastern Atlantic from the

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margi ...

off western Ireland south to Namibia, including the waters off the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

and the

Cape Verde Islands Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...

. In the Mediterranean Sea it is known from the waters around Spain and Morocco, the

Ligurian Sea The Ligurian Sea is an arm of the Mediterranean Sea. It lies between the Italian Riviera ( Liguria) and the island of Corsica. The sea is thought to have been named after the ancient Ligures people. Geography The sea borders Italy as far as ...

and the seas around Greece.

Habitat and biology

''Trachyrincus scabrus'' is a bathydemersal, non-migratory fish which occurs at depths which range from 400m to 1,700m over soft substrates. Its main food is pelagic

copepods Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (living in the water column), some are benthic (living on the sediments), several species have ...

but also takes mysids,

shrimps A shrimp (: shrimp ( US) or shrimps ( UK)) is a crustacean with an elongated body and a primarily swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchiata, although some crustaceans outside of this orde ...

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

, fish,

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are m ...

and

gastropods Gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. Ther ...

. This species spawns in winter, during February and March in the Mediterranean. The maximum recorded age of species is 10 year, the specimen being collected in the

Ionian Sea The Ionian Sea (, ; or , ; , ) is an elongated bay of the Mediterranean Sea. It is connected to the Adriatic Sea to the north, and is bounded by Southern Italy, including Basilicata, Calabria, Sicily, and the Salento peninsula to the west, ...

Fisheries

''T. scabrus'' is taken as bycatch throughout its range but it is usually utilised to make fishmeal and oil.

International Council for the Exploration of the Sea The International Council for the Exploration of the Sea (ICES; , ''CIEM'') is a regional fishery advisory body and the world's oldest intergovernmental science organization. ICES is headquartered in Copenhagen, Denmark, where its multinational s ...

(ICES) has advised that for the years 2016–2020 there should be no directed fisheries effort for this species and that any bycatch should be counted against the total allowable catch so that any potential misreporting through misidentification is minimised. In most years landings were negligible and in the only year ICES had statistics, 2012, 57 tonnes were landed in the whole of the north-east Atlantic.

References

{{Taxonbar, from=Q1966433 Macrouridae Fish described in 1810 Taxa named by Constantine Samuel Rafinesque