New Zealand Journal of Marine and Freshwater Research abstracts
Date and age at migration in juvenile giant kokopu, Galaxias
argenteus (Gmelin) (Teleostei: Galaxiidae) and estimation of spawning
season
R. M. MCDOWALL
G. R. KELLY
National Institute of Water & Atmospheric
Research
P. O. Box 8602
Christchurch, New Zealand
Abstract Juveniles of giant kokopu (
Galaxias argenteus
(Gmelin)) that had newly entered fresh water were captured, primarily from
the Buller and Hokitika Rivers, New Zealand, between 5 November and 15 December
(when sampling ceased). Age at migration estimated from otolith daily growth
rings was mostly c. 104-140 days. There is a positive relationship between fish
length and number of otolith growth rings at migration, though variation is
broad. Back calculation to hatch indicated that hatching occurred 185-245 days
after 1 January (4 July-2 September); allowing 28 days for development, these
data suggest that giant kokopu spawn between early June and early August.
Keywords daily growth rings; otoliths; giant kokopu;
spawning; New Zealand
M98041
Received 14 July 1998; accepted 28 October 1998
PDF file of entire paper: medium quality (1005K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
