Family Phosichthyidae

Taxonomy: Family with about 26 species in 7 genera; 5 genera with 13 species known from Australian waters.

Distribution, ecology and habitat: Worldwide in all oceans; meso- and bathypelagic in oceanic waters and over continental slope; some thought to be benthopelagic.

Characteristics:
Body slender, compressed, head small to moderate, mouth large, jaw teeth small to large, not long and fang-like; chin barbel absent, gill rakers usually well-developed, pseudobranch present. Photophores in two or more ventrolateral rows, usually two rows before anal-fin origin and a single row to caudal fin; orbital photophores usually two, isthmus with row of photophores, those behind pelvic fin in clusters. Dorsal fin small, usually near midbody, usually well in advance of anal-fin origin; anal fin not extending onto caudal peduncle; pectoral and ventral fins small; dorsal adipose fin usually present, ventral adipose fin present in some; bony pectoral-fin radials three. Scales cycloid, weakly attached.

Size: Reach about 30 cm, most less than 10 cm in length, some only growing to 4 cm.

Food and feeding: Feed primarily on zooplankton, especially small crustaceans.

Reproduction and early life history: Oviparous, planktonic eggs and larvae. Eggs small, spherical with clear shells, yolk segmented, oil globules present or absent. Larvae very similar to those of gonostomatids and sternoptychids, slender, elongate, preanus length relatively long, with a short "white" photophore stage where photophores are unpigmented at formation, then develop pigment simultaneously. Larvae at hatching - eyes unpigmented, mouth non-functional, yolk sac large, gut may trail.

Fisheries: None - Lightfishes are rarely captured even in very deepwater trawls.

Australian species:

References:

Harold, A.S. 1999. Gonostomatidae, Sternoptychidae, Phosichthyidae, Astronesthidae, Stomiidae, Chauliodontidae, Melanostomiidae, Idiacanthidae, and Malacosteidae. In Carpenter, K.E. & V.H. Niem. Species identification guide for fisheries purposes. The living marine resources of the western central Pacific. Batoid fishes, chimeras and bony fishes part 1 (Elopidae to Linophrynidae). FAO, Rome.

Harold, A.S. & S.H.Weitzman. 1996. Interrelationships of Stomiiform Fishes, pp. 333-353. In Stiassny, M.L.J., L.R. Parenti & G.D. Johnson (eds.) The Interrelationships of Fishes. Academic Press, London.

Parin, N.V. & O.D. Borodulina. 1990. Survey of the genus Polymetme (Photichthyidae) with a description of two new species. Vopr. Ikhtiol. 30: 733-743.

Richard, W.J. 2006. Ch. 18 Phosichthyidae: Lightfishes, p. 247, 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.

Schaefer, S., R.K. Johnson & J. Babcock. 1986. Family No. 73: Photichthyidae (pp. 243-247), Family No. 74: Gonostomatidae, pp. 247-253 In smith, M.M. & P.C. Heemstra. Smiths' Sea Fishes. J.L.B. Smith Inst. Ichthyol., Grahamstown, South Africa.