Family Aphyonidae
Taxonomy: Small family with 6 genera with about 22 species; 3 genera with 2 described and at least 2 undescribed species in Australian waters.
Distribution, ecology and habitat: Worldwide in all three major oceans at lower latitudes; mostly bathypelagic on continental shelf to abyssal depths between 2000 & 6000 m, a few species are benthic. benthopelagic
Characteristics:
Body elongate, eyes small or indistinct, no sensory pores on head; opercular spine weak or absent; mouth large, teeth small. Single long-based dorsal fin originating well behind head, continuous caudal fin and long-based anal fin; pelvic fins jugular, reduced to a single ray or absent. Skin loose, naked, gelatinous and transparent. Males with an intromittent organ, females often with fleshy appendages around genital opening.
Most species retain neotonous (larval features) such as the absence of scales, swim bladder and pyloric caecae; bones, musculature, gill rakers and gill filaments are poorly ossified; vertebral centra are cylindrically-shaped; sensory organs - eyes, nasal organ and lateral line are rudimentary.
Size: 5 to 20 cm, most about 10 cm.
Food and feeding: Crustaceans have been found in stomach contents.
Reproduction and early life history: Aphyonids are ovoviviparous with males having specialized copulatory organs for mating. Males produce bundles of sperm (spermatophores) and after mating, females are capable of storing spermatophores in bilobed ovaries until the eggs are ready to be fertilized.
Larvae very poorly known, and only one, caught in epipelagic waters, has been identified to species; unlike larvae of other ophidiids, larvae of aphyonids do not have coiled guts. Newly born young of deep-dwelling species are relatively large, suggesting they remain near the bottom after birth.
Fisheries: none
Australian species:
- Aphyonus gelatinosus Günther, 1878 Gelatinous Blindfish CAAB 37228014
- Barathronus maculatus Shcherbachev, 1976 Spotted Gelatinous Cusk CAAB 37228015
References:
Cohen, D.M. & J.G. Nielsen. 1978. Guide to the identification of genera of the fish order Ophidiiformes with a tentative classification of the order. NOAA Tech. Rep. NMFS Circ. 417: 1-72.
Fahay, M.P. & J.A. Hare. 2006. Ch. 49 Order Ophidiiformes: Aphyonidae, Bythitidae, Ophidiidae, p. 661-, In W.J. Richards (ed). Early Stages Of Atlantic Fishes: An Identification Guide For The Western Central North Atlantic. CRC Press, Taylor and Francis Group, Boca Raton, FL, 2640 pp.
Gordon, D.J., D.F. Markle & J.E. Olney. 1984. Order Ophidiiformes, pp. 308-319 In Moser H.G., W.J. Richards, D.M. Cohen, M.P. Fahay, A.W. Kendall, Jr. & S.L. Richardson (eds). Ontogeny and Systematics of Fishes. Am. Soc. Ichthyol. Herpetol. Spec. Publ. No. 1. 760 pp.
Nielsen, J.G. 1969. Systematics and biology of the Aphyonidae (Pisces, Ophidioidea). Galathea Rept. 10: 90 pp.
Nielsen, J.G. 1984. Parasciadonus brevibrachium n. gen. et sp. - an abyssal aphyonid from the Central Atlantic (Pisces, Ophidiiformes). Cybium 8: 39-44.
Nielsen, J.G., D.M. Cohen, D.F. Markle & C.R. Robins. 1999. FAO species catalogue. Volume 18. Ophidiiform fishes of the world (Order Ophidiiformes). An annotated and illustrated catalogue of pearlfishes, cusk-eels, brotulas and other ophidiiform fishes known to date. FAO Fish. Synop. No. 125, 178 pp.
Okiyama, M. & Kato, H. 1997. A pelagic juvenile of Barathronus pacificus (Ophidiiformes: Aphyonidae) from the southwest Pacific. Ichthyol. Res. 44(2): 222-226.