REPRODUCTIVE CYCLING AND FECUNDITY ESTIMATION IN THE UPLAND BULLY

Citation
Rm. Mcdowall et Ga. Elbon, REPRODUCTIVE CYCLING AND FECUNDITY ESTIMATION IN THE UPLAND BULLY, Journal of Fish Biology, 51(1), 1997, pp. 164-179
Citations number
25
Categorie Soggetti
Marine & Freshwater Biology
Journal title
ISSN journal
00221112
Volume
51
Issue
1
Year of publication
1997
Pages
164 - 179
Database
ISI
SICI code
0022-1112(1997)51:1<164:RCAFEI>2.0.ZU;2-N
Abstract
The upland bully is a prolific and widespread member of New Zealand fr eshwater fish communities that may mature at age 1 (or earlier). It be gins spawning in spring, laying as many as eight clutches of eggs over the spring and summer, at periods as brief as 13 days. Ovaries contai n two modes of maturing oocytes, so that oogenesis must be continual d uring the spawning season. This poses difficulties in fecundity estima tion, which were solved by captive rearing. The ovoid eggs are about 2 mm long; egg size declines with clutch number during the summer, but increases with fish size. Clutch size varied, in 70 spawnings, From 12 1 to 880 eggs, with total seasonal fecundity up to >5000 eggs. The pro duction of multiple clutches greatly increases seasonal fecundity and may explain the success of this species in sometimes unreliable or har sh environments. (C) 1997 The Fisheries Society of the British Isles.