Effects of salinity on nest-building behaviour in a marine fish.

Topi K Lehtonen,Charlotta Kvarnemo,Bob B M Wong

doi:10.1186/s12898-016-0067-y

Topi K Lehtonen, Charlotta Kvarnemo + Show 1 more

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https://doi.org/10.1186/s12898-016-0067-y

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Abstract

BackgroundParental allocation and reproductive success are often strongly influenced by environmental factors. In this respect, salinity is a key factor influencing species distributions and community structure in aquatic animals. Nevertheless, the effects of salinity on reproductive behaviours are not well known. Here, we used the sand goby (Pomatoschistus minutus), a small fish inhabiting a range of different salinities, to experimentally assess the effects of changes in salinity on nesting behaviour, a key component of reproduction in sand gobies and many other taxa.ResultsWe found that salinity levels influenced some aspects of male nesting behaviour (i.e. nest entrance size) but not others (i.e. latency to build a nest, choice of nest site, sand on top of nest) and that small and large individuals were differently affected. In particular, the importance of body size in adjustment of nest entrance depended on the salinity level.ConclusionThe results support the prediction that geographically widespread aquatic species, such as sand gobies, are able to perform well under a range of salinity levels. The phenotype by environment interaction found between male size and behavioural responses to salinity can, in turn, help to explain the notable variation observed in nest-building (and other) behaviours closely linked to reproduction.Electronic supplementary materialThe online version of this article (doi:10.1186/s12898-016-0067-y) contains supplementary material, which is available to authorized users.

Highlights

Parental allocation and reproductive success are often strongly influenced by environmental factors
Males showed a strong preference towards medium-sized nest sites (61 medium nests chosen in 100 trials; binomial distribution with the H0 being that a medium-sized nest would be chosen every third time, p < 0.001), indifference towards large nest sites (32 large nests chosen out of 100 trials; binomial distribution, p = 0.87) and avoidance of small nest sites (7 small nest chosen; binomial distribution, p < 0.001)
One possible reason is that the costs of caring for broods is unaffected by differently sized nest sites, as found in a study where male size and brood size were kept constant [69], or that the costs of caring for differently sized broods is unaffected by different salinity levels

Summary

Introduction

Parental allocation and reproductive success are often strongly influenced by environmental factors In this respect, salinity is a key factor influencing species distributions and community structure in aquatic animals. Parental allocation and reproductive success are often strongly influenced by environmental factors [1] This is especially true in species that rear their eggs or young in purpose-built nests [2,3,4,5], with nest builders often adjusting their choice of nesting site or nest architecture according to local environmental conditions [6,7,8]. Salinity can affect metabolic costs and growth rates of both adults and juveniles—even in species capable of surviving under a range of salinity levels [22,23,24,25] Aside from such metabolic and physiological effects, salinity can affect the costs and benefits of parental behaviours. Egg development of many marine species in the Baltic Sea is affected by the lower salinity levels [29,30,31,32], with gametes of commercially important taxa—such as cod, Gadus morhua, and flatfishes—being close to the limit of their salinity tolerance, while showing local adaptation to salinity [19, 30, 33, 34]

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