%0 Journal Article
%T Alternative Reproductive Tactics in the Shell-Brooding Lake Tanganyika Cichlid Neolamprologus brevis
%A Kazutaka Ota
%A Mitsuto Aibara
%A Masaya Morita
%A Satoshi Awata
%A Michio Hori
%A Masanori Kohda
%J International Journal of Evolutionary Biology
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/193235
%X Alternative reproductive tactics (ARTs) are found in several Lake Tanganyika shell-brooding cichlids. Field studies were conducted in the Wonzye population to examine reproductive ecology and ARTs in the Lake Tanganyika shell-brooding cichlid Neolamprologus brevis. We discovered that this fish occurred in both rocky- and sandy-bottom habitats, but in rocky habitats, brood-caring females exclusively occurred in shell-patches that another cichlid species created. All N. brevis of both sexes in the patches were sexually mature, whereas immature males and females with unripe eggs were found frequently in sandy-bottom habitats. Males in sandy-bottom habitats were smaller, but fed more frequently and were in better somatic condition than males in the patches. Similar tendency was found in females. This indicates that N. brevis uses different habitats depending on the stage of its life history, with migration from sandy-bottom habitats to the shell-patches for reproduction. Males in the patches exhibited different behavior patterns: floating above the patches and lying in the patches. The former was larger, more aggressive, and invested less in gonads (relative to body size) than the latter. These results accord with those of other shell-brooding Lake Tanganyika cichlids with ARTs, and they therefore suggest the presence of ARTs in N. brevis. 1. Introduction In species where males hold the resources required for breeding, reproductive behavior is often associated with ˇ°bourgeoisˇ± territorial tactics that involve defense of resources in an attempt to monopolize mating opportunities [1¨C4]. Bourgeois tactics are usually adopted by males who achieve competitive superiority (and also attractiveness) thorough behavioral (e.g., antagonistic behaviors) and morphological investments (e.g., large body size). These exclude less competitive males from reproduction. Such intrasexual competition for mating may lead to the evolution of alternative reproductive tactics (ARTs) [5, 6]. Competitively inferior, less attractive, and smaller subordinate males are unlikely to monopolize opportunities for mating, but they may evade monopolization by bourgeois males by using reproductively ˇ°parasiticˇ± tactics that often involve ˇ°sneakyˇ± behavior and the theft of reproductive efforts by bourgeois males [1, 3, 4, 6]. ARTs inherently give rise to sperm competition, that is, a competition among sperm from different males for the fertilization of ova [7]. Subordinate males exhibiting ˇ°sneakyˇ± mating behavior (i.e., sneakers) face a high probability that their sperm will encounter sperm
%U http://www.hindawi.com/journals/ijeb/2012/193235/