Seasonal reproduction, multiple spawning, and fecundity in northern krill, Meganyctiphanes norvegica, and Antarctic krill, Euphausia superba

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Author: Cuzin-Roudy, J
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2000
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Antarctic; Antarc*; Antarctic Krill; Euphausia superba; Meganyctiphanes norvegica; Northern krill
• Online Access: https://hal.science/hal-03483090; https://doi.org/10.1139/cjfas-57-S3-6

2nd International Symposium on Krill, UNIV CALIF SANTA CRUZ, SANTA CRUZ, CALIFORNIA, AUG 23-27, 1999 International audience 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.