Euclichthys

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Euclichthys
Euclichthys polynemus, drawing from the first description

Euclichthys polynemus , drawing from the first description

Systematics
Acanthomorphata
Paracanthopterygii
Order : Cod-like (Gadiformes)
Subordination : Gadoidei
Family : Euclichthyidae
Genre : Euclichthys
Scientific name of the  family
Euclichthyidae
Cohen , 1984
Scientific name of the  genus
Euclichthys
McCulloch , 1926

Euclichthys ( Gr .: "Eukles", - "es" = wonderful, "ichtys" = fish) is a species of fish belonging to the cod-like order(Gadiformes). The three species of the genus live south, east and west of Australia , New Caledonia and New Zealand at depths of 220 to 1040 meters.

features

Photo of the holotype of Euclichthys polynemus kept in the Australian Museum

Euclichthys species are medium-sized (maximum standard length 33.5 cm), cod-like fish. Your body is elongated, flattened on the sides and tapers backwards. The head length is 18 to 22% of the standard length. The mouth is large and terminal or slightly below. The goatee typical of many cod-like fish is missing. Palatine teeth are missing. The scales are round, overlap and fall off slightly. The first dorsal fin is high, has a short spine and 11 to 15 fin rays, and begins just behind the head. The second dorsal fin is long, with 67 to 88 fin rays and extends to the caudal fin. The anal fin is deeply indented with a short but high first and a lower second section. The second section is very low in the front part and higher in the rear, but always lower in the rear than the second dorsal fin. The anal fin ends just before the end of the dorsal fin. The reduced, asymmetrical caudal fin has not grown together with the anal fin. The pelvic fins consist of three thread-like upper fin rays that have grown together over about a third of their length and three thread-like, free lower fin rays. They are throaty, their base lies in front of the preoperculum . The pectoral fin attachment is relatively far down on the body, so the gill openings extend far above the pectoral fin attachment. The fish are light with a more or less clearly demarcated dark luminous organ on the underside of the head and trunk. The fins are largely translucent and may have dark edges.

species

The three Euclichthys species with their distribution and the meristic (countable) determination criteria:

Fin formula : Dorsal I / 12-14, 70-82; Anal I / 84-101; Pectorals 19-20; Caudals 38-45
Gill rake : 6 / 17-19
Vertebra: 66-69
Fin formula: Dorsal I / 11-13, 67-75; Anal I / 78-88; Pectorals 21-23; Caudals 30-35
Gill rake: 4–5 / 12–14
Vertebra: 64-66
Fin formula: Dorsale I / 12-15, 78-88; Anal I / 92-102; Pectorals 20; Caudals 37-43
Gill rake: 5–6 / 15–17
Vertebra: 68-73

The Euclichthys species are of no economic importance.

Systematics

Euclichthys polynemus , the first and for a long time the only known species of the genus, was first described scientifically together with the genus Euclichthys when the Australian ichthyologist Allan Riverstone McCulloch evaluated the catches of a research trawler (Fisheries Investigation Ship Endeavor ) . McCulloch introduced Euclichthys polynemus into the family of deep-sea cod (Moridae). However, Euclichthys polynemus differs from these by the asymmetrical anal and caudal fin. Later authors assigned the species to the black cod (Melanonidae), the cod (Gadidae), or classified the species as incertae sedis in the order of the cod-like (Gadiformes). In 1984, the American ichthyologist Daniel M. Cohen introduced the monotypic family Euclichthyidae for the genus. The Australian ichtyologists Peter R. Last and John J. Pogonoski described two more species in March 2020, Euclichthys microdorsalis has a shorter dorsal fin, a longer snout and smaller eyes than E. polynemus and Euclichthys robersti remains smaller than E. polynemus , has a smaller one , slimmer head, smaller eyes, smaller scales and a longer anal fin.

literature

  • Last, PR & Pogonoski, JJ (2020): Revision of the fish family Euclichthyidae (Pisces: Gadiformes) with the description of two new species from the Western Pacific. Zootaxa, 4758 (2): 231-256. DOI: 10.11646 / zootaxa.4758.2.2

supporting documents

  1. ↑ Last & Pogonoski (2020), page 234.
  2. ↑ Last & Pogonoski (2020), page 237.
  3. ^ Last & Pogonoski (2020), page 246.
  4. ^ McCulloch, AR 1926. Report on some fishes obtained by the FIS "Endeavor" on the coasts of Queensland, New South Wales, Victoria, Tasmania, South and South-Western Australia. Part V. Biological Results Endeavor v. 5 (pt 4): 157-216, Pls. 43-56.
  5. ↑ May, JL & Maxwell, JGH (1986) Trawl fish from temperate waters of Australia. CSIRO Division of Fisheries Research, Hobart, 492 pp.
  6. ^ Ayling, T. & Cox, GJ (1982) Collins guide to the sea fishes of New Zealand. Collins, Auckland, 343 pp.
  7. ↑ Fahay, MP & Markle, DF (1984) Gadiformes: development and relationships. In: Moser, HG (Ed.), Ontogeny and systematics of fishes. American Society of Ichthyologists and Herpetologists Special Publication, 1, pp. 265-283.
  8. ^ Cohen, DM (1984) Gadiformes: overview. In: Moser, HG (Ed.), Ontogeny and systematics of fishes. American Society of Ichthyologists and Herpetologists, Special Publication, 1, pp. 259-265.
  9. Jump up ↑ Last, PR & Pogonoski, JJ (2020): Revision of the fish family Euclichthyidae (Pisces: Gadiformes) with the description of two new species from the Western Pacific. Zootaxa, 4758 (2): 231-256. DOI: 10.11646 / zootaxa.4758.2.2