Advancing mate choice studies in salmonids

Abstract

Mate choice in most organisms is not random, but determined by a suite of interacting traits and environmental factors. While the selective pressures underlying differences in mate choice between species, populations, individuals and even within individuals has been gaining interest, there still remains unexplained variation in mate preferences especially in non-model systems. Despite being of social, environmental and economic importance there is comparatively little known about how salmonids and other tetraploids make mate choice decisions in the wild and the resultant reproductive success (i.e. the number of offspring which survive to sexual maturity). Resolving questions related to salmonid mate choice is of particular importance given that humans have been supplementing salmon populations through aquaculture for decades. Despite these efforts, hatchery produced fish have lower reproductive success relative to their wild counterparts and salmon populations are declining. Most studies on mate choice and reproductive success in salmonids focus on body size and major histocompatibility complex based choice. However, mate choice can also be affected by other factors including other genetic factors, predation risk and social environment. Here, we (a) synthesize what is presently known about mate choice and reproductive success in salmonids, (b) identify gaps in knowledge and areas where there is a lack of consensus in results, and (c) suggest interdisciplinary ways of advancing our understanding of mate choice in salmonids and other polyploids.

Time spent in distinct life history stages has sex‐specific effects on reproductive fitness in wild Atlantic salmon

“…However, we should be careful with this interpretation as no information on reproductive success of these parr in our study population is currently available, yet the occurrence of mature male parr in the region is estimated to be around 10% (Heinimaa & Erkinaro, 2004). Further research is warranted to uncover the extent to which sexual selection operates on males and females in this and indeed other species of salmonids (Auld, Noakes, & Banks, 2019).…”

Host‐specific preference of some Flavobacteriumpsychrophilum multilocus sequence typing genotypes determines their ability to cause bacterial coldwater disease in coho salmon (Oncorhynchuskisutch)

“…To more closely mimic a natural route of infection, this study utilized immersion challenge in combination with clipping of the adipose fin, a practice commonly utilized in salmonid hatcheries to delineate hatchery fishes from their wild counterparts (Auld et al., 2019). By allowing two genetically and serologically distinct F .…”

Maturation in Atlantic salmon (Salmo salar, Salmonidae): a synthesis of ecological, genetic, and molecular processes

“…Increased reproductive success among older, and therefore larger, individuals is potentially due to their increased competitive ability on the spawning grounds. Differences in competitive ability are likely mediated by size-and age-related differences in aggression and courtship behaviors, gamete competition, as well as mate choice (Auld, Noakes, & Banks, 2019;Fleming, 1998;Gage et al, 2004;Mjølnerod, Fleming, Refseth, & Hindar, 1998). For example, body size affects dominance hierarchies, with larger females defending high quality spawning areas [e.g., fast flowing water (Crisp & Carling, 1989)] and thus obtaining higher mating and reproductive success (Fleming, 1996;Fleming & Einum, 2011).…”