Nettastoma melanurum

Nettastoma melanurum

The blackfin sorcerer (Nettastoma melanurum Rafinesque, 1810) is an abyssal fish belonging to the Nettastomatidae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota Domain,
Kingdom Animalia,
Phylum Chordata,
Subphylum Vertebrata,
Infraphylum Gnathostomata,
Actinopterygii class,
Subclass Neopterygii,
Infraclasse Teleostei,
Superorder Elopomorpha,
Order Anguilliformes,
Nettastomatidae family,
Genus Nettastoma,
N. melanurum species.
The terms are synonymous:
– Hyoprorus messanensis Kölliker, 1853;
– Hyoprorus messinensis Kölliker, 1853;
– Leptocephalus longirostris Kaup, 1856;
– Leptocephalus urosema Lea, 1913;
– Mettastoma melanurum Rafinesque, 1810;
– Muraena saga (Risso, 1810);
– Muraenophis saga Risso, 1810;
– Muraenosaurus guentheri Osório, 1909;
– Muraenosaurus güntheri Osorio, 1909;
– Murenophis saga Risso, 1810;
– Nettastoma melanorum Rafinesque, 1810;
– Nettastoma melanura Rafinesque, 1810;
– Nettastoma mendax Facciolà, 1893;
– Nettastoma saga (Risso, 1810);
– Osorina guentheri (Osorio, 1909).

Geographic Distribution and Habitat –
The blackfin sorcerer is a fish that lives in the coastal waters of the Atlantic Ocean and also in the western Mediterranean Sea. It is more frequent in the waters surrounding the Caribbean, the Azores, the Canary Islands and the northern Mediterranean Sea, while it is very rare in the Adriatic Sea.
In the Italian seas it is quite common in the Ligurian, Tyrrhenian, Ionian and Sicilian seas.
Its habitat is that of deep waters, between 37 and 1647 meters but the maximum density is around 600 m. It populates muddy bottoms in which it lives sunken.

Description –
Nettastoma melanurum is an eel-like fish, usually 50-60 cm long but can reach 80 cm, with an elongated body, cylindrical in front and compressed in the back while the tail is thin and pointed.
The body is gray-brown, darker on the back and with silver reflections on the abdomen. The dorsal goes from dark brown at the beginning to a lighter brown in the central area, until it becomes black towards the caudal area. The anal is lighter anteriorly, black posteriorly. Both dorsal and anal are bordered in white.
It has flaky skin and a series of pores along the lateral line. The gill openings are oval in shape.
The head and muzzle are elongated and the latter is also flattened and with a fleshy tubercle at the upper end.
The eyes are developed and oval. The anterior nostrils are tubular, the posterior ones are equipped with a mobile dermal flap.
The mouth is wide and with a prominent upper jaw. The tongue adheres to the buccal floor. In both jaws there are sets of small teeth.
The dorsal fin is high and the interradial membrane is solid. The anal is a little lower and connects with the dorsal at the tail extremity. Instead, the pectoral fins are missing.

Biology –
Nettastoma melanurum is a fish in which reproduction occurs all year round.
The larvae are leptocephalic. They have a very flattened body laterally, shaped like a willow leaf.
The larvae go through a metamorphosis according to the following stages:
– Prelarva;
– Larva (ribbon-like leptocephalus);
– Semilarva (cylindrical leptocephalus);
– Transitional form with the adult.
These larvae are planktonic and feed on small crustaceans and other plankton animals.

Ecological Role –
The Nettastoma melanurum is a fish that lives in holes and ravines on the bottom of the continental slopes where it lives in deep waters on seabeds. Its natural predators are cod-like fish such as the European hake.
Instead, it is a predatory fish that feeds on benthic invertebrates and fish, mainly lantern fish.
This fish is caught by the trawl nets of offshore fishing boats and also bites the longlines, however its small size and its position on the bottom of the continental slopes do not make it dangerous for humans and moreover it is of no use for the fishing due to the abundance of other eels which are easier to spot and catch. Among other things, the meats, even if edible, are smooth and for this reason it is almost never found on the markets.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– Louisy P., 2016. Guide to the identification of marine fish of Europe and the Mediterranean. Il Castello Editore, Milan.
– Nikiforos G., 2008. Mediterranean fauna. Giunti Editore, Florence.
Photo source:
– http://photos.gbif.fr/mnhn_nice/aquarelles_animaux_marins_et_plantes/2005-0-1057.jpg
– https://fishesofaustralia.net.au/home/species/3414