Reproductive biology of the pufferfish, Uranostoma richei (Plectognathi: Lagocephalidae), from Lyttelton harbour

The gonads of 15 163 pufferfish, Uranostoma richei (Freminville), taken from Lyttelton Harbour, South Island, New Zealand between June 1969 and May 1970 were examined; 8892 were female, 6271 male. A smaller number of gonads and livers were examined in detail. The occurrence of fish at different stages of gonad development during the year, and associated changes in gonad weight, were used to define the breeding season as October to March. Peak spawning occurred in December; spawning fish were over 7.5 cm in length, 9 g in weight, and 2 years of age. Fecundity (counts of eggs over 0.4 mm diam.) was proportional to the cube of fish length, and ranged from 5000 in a fish of 8 cm to 100 000 in an 18‐cm‐long fish. There was some evidence that the liver acts as a food store that is utilised in gonad development before spawning.

Notes

Present address: Fisheries Research Division, Ministry of Agriculture & Fisheries, P.O. Box 19062, Wellington, New Zealand