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Reproductive behaviour and early development of the Drysdale hardyhead, Craterocephalus sp. nov. (Pisces: Atherinidae), from the Alligator Rivers System, Northern Territory, Australia
Author(s) -
Semple G. P.
Publication year - 1986
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1986.tb04965.x
Subject(s) - hatching , biology , demersal zone , alligator , hatchling , yolk , larva , yolk sac , seasonal breeder , fishery , zoology , juvenile , sexual dimorphism , ecology , anatomy , fish <actinopterygii> , embryo
Craterocephalus sp. nov. showed sexual dimorphism in body shape during the breeding season. Pairing occurred during daylight with a single release of eggs amongst submerged vegetation between sunrise and the early afternoon on the same day. The eggs were demersal, adhesive, spherical (0.87–0.96 mm diameter) and had 12 adhesive filaments (0.5–1.5 mm long) at the animal pole. Approximately 24 oil droplets (0.02–0.08 mm diameter) persisted throughout egg and larval development. Hatching occurred 155–160 h after spawning at 25–27° C. The yolk‐sac larvae were 3.85–3.95 mm notochord length at hatching and began feeding at the surface after absorption of the yolk (3–12 h after hatching). All fin rays were developed in 9.4 mm standard length fry, which moved from midwater to feed on the substrate. Aquarium reared fish first spawned at 30 mm s.L. when 165 days of age. Features of Craterocephalus reproduction, as they relate to a specific survival strategy, are briefly discussed.