Cataetyx alleni

Cataetyx alleni

The Allen’s brotula (Cataetyx alleni Byrne, 1906) is a marine bony fish belonging to the Bythitidae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Phylum Chordata,
Class Actinopterygii,
Order Ophidiiformes,
Family Bythitidae,
Genus Cataetyx,
Species C. alleni.
The terms are synonymous:
– Cataetyx brevis (Koefoed, 1927);
– Cataetyx leucos (Osório, 1917);
– Grammonus leucos Osório, 1917;
– Oculospinus brevis Koefoed, 1927;
– Pteridium alleni Byrne, 1906.

Geographic Distribution and Habitat –
Cataetyx alleni is a marine fish present in an area that includes the Mediterranean Sea and the eastern Atlantic Ocean, in particular from the French to Portuguese coasts.
It is an uncommon fish except in some small marine areas where it can be more abundant.
In Italy it is reported in the Ligurian Sea, the Gulf of Naples and the Strait of Messina.
As regards its habitat, it is a deep-water bathypelagic marine species, with demersal behavior, which lives at depths between 480 and 1,000 metres.

Description –
Cataetyx alleni is a small fish that can measure up to 12 cm in length.
It has an elongated and laterally compressed body, with beige coloring on the back and sides with a light belly.
The head and mouth are relatively large.
It has small scales but absent in some areas of the head.
The lateral line is broken, from the operculum to the origin of the anal fin it runs high; near the dorsal margin of the body then, at the height of the pectoral fin, it starts again in the ventral area and almost reaches the caudal peduncle.
The dorsal and anal fins are long, with the dorsal longer; furthermore the dorsal fin has 109-111 rays, the anal 79-83, the pectoral 31-32, the caudal 8 and the ventral only one filiform ray. The caudal fin is distinct. It also has ventral fins.
In addition, there are a group of brown chromatophores that concentrate at the beginning of the lateral line.

Biology –
Cataetyx alleni is a fish with little known biology, also due to the depths where it lives and reproduces.
It is known to be a viviparous species

Ecological role –
Cataetyx alleni is a bathidemersal fish found on muddy bottoms from 480 to over 1000 m. It feeds on polychaetes and epibenthic and endobenthic crustaceans and sometimes on benthic fish.
Its capture is occasional and is done with bottom trawls on deep seabeds. It also has no commercial interest.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Louisy P., 2016. Guide to the identification of marine fish of Europe and the Mediterranean. Il Castello Editore, Milan.
– Nikiforos G., 2008. Fauna of the Mediterranean. Giunti Editore, Florence.