Abstract

The reproductive performance of farmed Arctic charr exhibits substantial individual variation. The causes behind this variation have not yet been properly explained, despite the species relatively long history in aqua-culture. The aim of the present study was to provide better understanding of the issue by evaluating parent and gamete traits in relation to fertility and offspring viability under routine hatchery conditions. Are losses mainly due to failed fertilisation or mortality? Are maternal or paternal factor more predominant? The study covered sex hormone status of the broodstock, egg traits (egg size and wateriness of egg batches), milt traits (volume, density, and sperm motility characteristics), and symmetry of early cell division.We found that the majority of offspring loss occurred as embryo mortality, although a significant additional loss could be assigned fertilisation failure. Fertilisation and mortality rates were not inter-correlated. Neither of the evaluated egg traits, egg size and wateriness of newly stripped egg batches, proved to be useful indicators of egg quality. With regard to sperm traits, milt density as well as several computer assisted sperm analysis (CASA) parameters, i.e. swimming speed (VAP, VSL, and VCL) and beat cross frequency (BCF), were correlated with reproductive performance and could potentially be used as quality indicators for Arctic charr. Together, male 17,20 beta-P levels and BCF explained 69.5% of the between male variation in proportion of successfully eyed eggs.The results support previous indications that post-ovulatory aging of oocytes is contributing to the impairment of reproductive performance in farmed Arctic charr. In addition, a significant paternal factor to this impairment has been exposed. However, the cause and mechanism involved are still far from clear.

Keywords

Reproduction; Arctic charr; Sperm quality; Egg quality; Sex steroids; Fertility

Published in

Aquaculture
2019, Volume: 504, pages: 446-453
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Jeuthe, Henrik

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • Vattenbrukscentrum Norr

• Brännäs, Eva

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.aquaculture.2019.02.024

Permanent link to this page (URI)

https://res.slu.se/id/publ/99063