Breeding and fecundity of
the endemic Australian gudgeon, sleepy cod Oxyeleotris lineolatus
(Steindachner 1867) (Eleotridae)
B.
Herbert, P. Graham-2004
Aquaculture, 236(1-4): 241-252
Abstract:
Sleepy cod (Oxyeleotris lineolatus
Steindachner) is a tropical species of eleotrid native to northern
Australia. A related species, sand or marbled goby, is the highest priced
freshwater fish in Asia, and a market for a similar fish exists in
expatriate Chinese communities. Sleepy cod breed when minimum temperatures
reach 24 °C for more than 3 days. During the breeding season the genital
papilla is broad and flattened in females compared to the triangular papilla
of males and juveniles. Spawning pairs were usually of approximately equal
size. Females could spawn up to 10 times during one breeding season. Wet
weather increased the frequency of spawning. Eggs were usually laid hanging
from the underside of a surface. Most spawning occurred between 05:00 and
10:00 h. Females attended egg masses immediately after spawning, after which
males cared for eggs until hatching, 3–5 days later. Agitation of the egg
mass was essential for development. The mean number of eggs per spawning was
43 130. Larvae commenced feeding 2–5 days after hatching, on plankton
from 100 to 250 µm in size. A spawning trap used to collect egg masses is
described. The breeding biology of sleepy cod is considered to be an
adaptation to the monsoonal tropics.
(Freshwater Fisheries and Aquaculture Centre,
Queensland Department of Primary Industries, Kennedy Highway, Walkamin,
Queensland 4872, Australia, e-mail: brett.herbert@dpi.qld.gov.au)