Logo image
Sperm characteristics and competitive ability in farmed and wild cod
Journal article   Open access   Peer reviewed

Sperm characteristics and competitive ability in farmed and wild cod

J E Skjaeraasen, I Mayer, Justin J Meager, G Rudolfsen, Ø Karlsen, T Haugland and O Kleven
Marine Ecology Progress Series, Vol.375, pp.219-228
2009
pdf
PDF - Published Version217.06 kBDownloadView
Published VersionPDF - Published Version Open Access
url
https://doi.org/10.3354/meps07774View
Published Version

Abstract

Fisheries Sciences Gadus morhua escapees sperm competition mating system reproductive roles
The development of cod aquaculture has raised concerns about its effect on wild stocks. One risk is hybridisation between escapees and wild cod, causing genetic introgression, and, potentially, fitness depressions in wild populations. The potential for hybridisation depends on escapee success in mating competition with wild fish. Cod have a complex mating system, with males likely to adopt either dominant or sub-dominant roles, the latter typically achieving reproductive success through sperm competition. Studies on salmonids indicate that domesticated males predominantly adopt sub-dominant roles. We therefore analysed sperm characteristics of wild and farmed cod Gadus morhua L. around the onset and end of the natural spawning season. Wild and farmed males were also paired in in vitro crosses to assess reproductive success in sperm competition. In the early spawning season, wild males had higher sperm velocity, percentages of motile and progressive cells, and spermatocrit. Sperm velocity was the main determinant of fertilisation success in in vitro sperm competition and, accordingly, wild males had higher reproductive success. At the end of spawning, the percentages of motile or progressive cells and spermatocrit were similar between wild and farmed males, but wild males maintained higher sperm velocity. Our results indicate that farmed males have limited reproductive success in sperm competition with wild male cod. This presumably reduces the risk of genetic introgression from escapees. We hypothesise that impaired sperm quality and lower reproductive fitness of farmed cod are due to inhibition of the full behavioural repertoire, lack of social structure under culture conditions, and/or nutritional deficiencies.

Details

InCites Highlights

These are selected metrics from InCites Benchmarking & Analytics tool, related to this output

Collaboration types
Domestic collaboration
Web Of Science research areas
Ecology
Marine & Freshwater Biology
Oceanography

UN Sustainable Development Goals (SDGs)

This output has contributed to the advancement of the following goals:

#14 Life Below Water

Source: InCites

Logo image