Sexual conflict over breeding substrate causes female expulsion and offspring loss in a cichlid fish (original) (raw)
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Sexual selection promotes colonial breeding in shell-brooding cichlid fish
Animal Behaviour, 2016
Colonial species breed in densely aggregated territories containing no other resources than nest sites. This behaviour is usually explained by natural selection, for instance through benefits resulting from reduced predation risk. An alternative hypothesis suggests that like in lek breeding systems, sexual selection may be responsible for the aggregation of competitors, driven by an increased potential for female mate choice among closely assembled males. Lamprologus callipterus, a shell-brooding cichlid fish of Lake Tanganyika, provides an ideal test case for the utility of lek evolution models to explain colonial breeding, because breeding territories are established by males before pairing. Large males collect and defend empty snail shells that are then chosen by females for breeding. We checked for a potential influence of sexual selection on colonial breeding in L. callipterus by testing predictions of the hot-shot hypothesis and female preference hypothesis of lek mating models. In the field, we found that territories of larger males were more centrally located, and that females preferred to breed with males surrounded by many neighbours, two findings that are consistent with lek mating models. Female preference suggests that sexual selection affects colonial breeding in L. callipterus, which implies an influence of sexual selection on the evolution of colonial breeding at large.
Behaviour, 1999
Female intra-sexual competition plays an important role in the settlement process during pair or harem formation and in established harems of Lamprologus ocellatus, a small snail shell inhabiting cichlid from Lake Tanganyika. Larger females settle rst and this could partly be due to male preference for larger females as shown in simultaneous choice tests but is also due to dominance of the larger female. Smaller females were unable to settle close to a larger one. Even when snail shells were not limiting the smaller was either unable to settle or had to settle at a considerable distance. This effect was independent of prior residence. Intense female-female aggression suggeststhat close settlement is disadvantageous 1) 4) We wish to thank Uwe Kohler for giving us the sequence of three primers and him and Sigal Balshine-Earn for sharing their knowledge about Lake Tanganyika around Mpulungu with us. Barbara and Michael Taborsky were most helpful in establishing contacts with Zambia and provided advice as well as diving equipment for our eld work at Lake Tanganyika. Diethard Tautz and his group provided invaluable help in Munich by rendering possible the cloning and sequencing of L. ocellatus DNA in his laboratory. Toby Veall advised us where to nd L. ocellatus near his lodge and we thank him and Pippa Bailey and Russel Young for their marvellous hospitality at the Kalambo Falls Lodge and Walther Brandtmann and Sandra Kolberg for their much appreciated eld assistance.
Ethology, 2004
Reproductive parasitism among males is prevalent in fishes. Typically, small ripe males parasitize the reproductive effort of large bourgeois males by using various behavioural tactics. We examined the size-dependent advantages of parasitic behavioural tactics in a shell-brooding cichlid fish of Lake Tanganyika with three male types (large bourgeois males and medium-dwarf parasitic males). The extremely small Ôdwarf malesÕ weighing only 2.5% on average of large males, perform a specialized tactic in which they avoid attacks by the resident large males by entering the inner part of the whorl of the shell where a female is spawning. Field observations and a manipulation experiment revealed that the very small size of dwarf males is essential for utilizing this positional advantage. Larger dwarf males and medium males opportunistically adopt darting and sneaking which likely result in very low reproductive outcomes. The size associated advantage and disadvantage of parasitic tactics are the major factors shaping the size distribution of ripe males in this species. The success of parasitic spawning by dwarf males is determined not only by body size of the males, but also by the relative sizes of females and shells in which they spawn. These factors would affect the choice of different tactics among dwarf males. The analyses of body condition among ripe and unripe males across a wide range of body sizes suggested that onset of sexual activities at very small body sizes in dwarf males may be associated with higher condition factors that is a pre-requisite for maintaining investment in testes and intense reproductive activities.
Alternative Reproductive Tactics in the Shell-Brooding Lake Tanganyika Cichlid Neolamprologus brevis
International journal of evolutionary biology, 2012
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 pa...
Journal of Ethology, 2007
We studied foraging site partitioning between the sexes in Neolamprologus tetracanthus, a shrimp-eating Tanganyikan cichlid with harem-polygyny. Females maintained small territories against heterospecific food competitors within large territories of males, foraging exclusively at the inner side of their own territories (foraging areas). Males fed as frequently as females in their own territories, but mostly outside female foraging areas, although they frequently entered female territories and repelled food competitors from the territories. Soon after removal of the resident females, however, harem males, as well as many food competitors, invaded the vacant territories and intensively devoured prey of female foraging areas. This indicates that although female foraging areas appear to contain more food than outside the areas, harem males refrained from foraging there when the resident females were present. We suggest that harem males will attempt to keep female foraging areas in good condition, whereby they may get females to reside in male territories and/or promote female gonadal maturation.
Reproductive behavior and parental roles of the cichlid fish Laetacara araguaiae
Neotropical Ichthyology, 2011
We described the reproductive behavior of the small South American cichlid Laetacara araguaiae in streams from Brazil. We predicted that this species will show reproductive cooperation and division of labor between males and females in a similar way presented by other substrate-spawner cichlids. Thus, we studied 34 pairs in the pre-spawning (n = 11), egg/wriggler (n = 11) and fry (n = 12) phases. In the pre-spawning phase both sexes become involved in nest building and territorial defense, but females emphasizes building nest (p = 0.03), while males invest more time in territorial defense (p = 0.04). After spawning, male and female alternate between rearing eggs and defending nest in the territory. In the egg/wriggler phase females devotes more time rearing the brood while males remain defending territory (p = 0.02). These differences disappear when young are in the fry stage, and parents jointly stay closer to fry (p = 0.98). However, at this phase, there is a reduction in the freq...
Journal of Fish Biology, 2009
A rare form of alternative reproductive behaviour without simultaneous parasitic spawning was observed in Ophthalmotilapia ventralis, a lekking mouth-brooding cichlid from Lake Tanganyika. Floater males attempted to sneak opportunistically into the territory to actively court the female, while the owner (bourgeois male) defended the territory against other potential intruders. Floater males had more body fat than territory owners and generally higher condition factors. In field experiments, the response of bourgeois males and courted females was tested towards floaters and egg predators (a catfish Synodontis multipunctatus) present in the territories. Territory owners responded aggressively particularly to floaters, and female responsiveness to bourgeois male courtship tended to decline when floaters were present. The potential influence of reproductive parasitism on sexual selection in mouth-brooding cichlids is discussed.