Item Details

Title: Life history change in response to fishing and an introduced predator in the East African cyprinid Rastrineobola argentea

Date Published: 2012
Author/s: Diana M. T. Sharpe, Silvester B. Wandera and Lauren J. Chapman
Data publication:
Funding Agency :
Copyright/patents/trade marks:
Journal Publisher:
Affiliation: Department of Biology, McGill University, Montre┬┤ al, Que┬┤ bec, Canada
2 National Fisheries Resources Research Institute (NaFIRRI), Jinja, Uganda
Keywords: anthropogenic stressors, contemporary
phenotypic change, dagaa, fisheries-induced
evolution, invasive species, life history
evolution, mukene.

Abstract:

Fishing and introduced species are among the most important stressors
affecting freshwaters and can also be strong selective agents. We examined the combined effects of commercial fishing and an introduced predator (Nile perch, Lates niloticus) on life history traits in an African cyprinid fish
(Rastrineobola argentea) native to the Lake Victoria basin in East Africa. To
understand whether these two stressors have driven shifts in life history traits of R. argentea, we tested for associations between life history phenotypes and the presence/absence of stressors both spatially (across 10 Ugandan lakes) and temporally (over four decades in Lake Victoria). Overall, introduced Nile perch and fishing tended to be associated with a suite of life history responses in R. argentea, including: decreased body size, maturation at smaller sizes, and increased reproductive effort (larger eggs; and higher relative fecundity, clutch volume, and ovary weight). This is one of the first well-documented examples of fisheries-induced phenotypic change in a tropical, freshwater stock; the magnitude of which raises some concerns for the long-term sustainability of this fishery, now the most important (by mass) in Lake Victoria.