Cryptic alternative male mating strategies in invasive alien round goby (Neogobius melanostomus) of the upper Danube River

Alexander F Cerwenka,Ulrich K Schliewen,Joerg Brandner,Juergen Geist

doi:10.1007/s10530-020-02389-0

Alexander F Cerwenka, Ulrich K Schliewen + Show 2 more

Open Access

https://doi.org/10.1007/s10530-020-02389-0

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Abstract

Male alternative mating strategies are a widespread life history choice, yet they have hardly been assessed in the context of fish invasions. As established proxies for alternative life-history strategies, body length and sexual maturity of Ponto–Caspian round goby (Neogobius melanostomus) from the recently invaded upper Danube River were contrasted and differential trophic niche occupation was assessed. Only about 4% of analyzed gobies qualified as potential sneakers which may be explained by the recent and ongoing invasion process. This study provides evidence for the occurrence of sneaking behavior of invasive round goby in the upper Danube River.

Highlights

Numerous and taxonomically widespread alternative reproductive strategies evolved within males, especially in species with (1) external fertilization, (2) egg guarding, or (3) high competition for a mating occasion (Taborsky et al 2008)
This study provides evidence for the occurrence of alternative male mating strategies in round goby during their ongoing invasion of the upper Danube River (Table 2)
This finding is novel in the context of a biological invasion process in the upper Danube River, alternative male mating strategies had been inferred for other round goby invasions, but with substantially different proportion estimates: whereas only about 4% round gobies were identified as sneakers in the invaded upper Danube River, much higher values of 40.6% in the River Rhine in the Netherlands (Bleeker et al 2017), and 39.3% (Bose et al 2018), 12 and 51% (Marentette et al 2009, 2010) in the Great Lakes in the USA were found

Summary

Introduction

Numerous and taxonomically widespread alternative reproductive strategies evolved within males, especially in species with (1) external fertilization, (2) egg guarding, or (3) high competition for a mating occasion (Taborsky et al 2008).

Results

Conclusion