Seasonal reproduction, multiple spawning, and fecundity in northern krill, Meganyctiphanes norvegica, and Antarctic krill, Euphausia superba
2nd International Symposium on Krill, UNIV CALIF SANTA CRUZ, SANTA CRUZ, CALIFORNIA, AUG 23-27, 1999 Both northern krill, Meganyctiphanes norvegica, and Antarctic krill, Euphausia superba, release eggs seasonally in multiple spawning events. Fecundity estimates were determined based on counts of mat...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
---|---|
Main Author: | |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2000
|
Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-03483090 https://doi.org/10.1139/cjfas-57-S3-6 |
Summary: | 2nd International Symposium on Krill, UNIV CALIF SANTA CRUZ, SANTA CRUZ, CALIFORNIA, AUG 23-27, 1999 Both northern krill, Meganyctiphanes norvegica, and Antarctic krill, Euphausia superba, release eggs seasonally in multiple spawning events. Fecundity estimates were determined based on counts of mature oocytes in the ovary of females in preserved field samples. Principal components analysis and allometry were used to analyze the covariation of egg-batch size with female characteristics. In both krill species, egg-batch size scaled isometrically with ovarian weight but showed a positive allometry with body size. Predicted egg-batch size ranged from 200 to 4000 eggs for M. norvegica of 25.5-35 mm body length and from 1500 to 6000 eggs for E. superba of 36-55 mm. Allometric relationships can be used to predict annual fecundity from size structure data of krill populations. In this study, the effect of temperature on the duration of molting and spawning cycles was used to infer a number of reproductive cycles per year. taking into account climate and seasonal variation. |
---|