Intensive collection in southern Mozambique across and outside the potential range of Nothobranchius furzeri, the species with the shortest recorded life span among vertebrates used as a model in ageing research, revealed that, contrary to previous data, it is a widespread species. It occurs in small freshwater pools south of the Save River and north of the Incomati River, including basins of the Limpopo, Changane, Chefu, Mazimechopes and Vaneteze Rivers. During collection in February 2008 (the second part of the rainy season), populations were strongly female biased (mean, 28% of males across 19 populations), and there was a spatial pattern in female bias among metapopulations. Populations varied in the proportion of male colour morphs. Fourteen populations were composed exclusively of the red male phenotype, three populations of the yellow male phenotype and 12 populations were mixed. Overall, the red phenotype was more common, but there was strong geographical variation in morph proportion, with yellow males more abundant at the periphery and red male dominance in the centre of the range of N. furzeri in the Limpopo basin. Nothobranchius furzeri was sympatric with Nothobranchius orthonotus (35% of investigated pools) and Nothobranchius rachovii (27% of sites). Analysis of habitat use of N. furzeri is presented; N. furzeri was associated with pools containing a soft muddy substratum and turbid water.

• MeSH
• demografie MeSH
• ekosystém MeSH
• fenotyp MeSH
• Fundulidae fyziologie   MeSH
• pigmentace MeSH
• poměr pohlaví MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Mosambik MeSH

Geographical isolation, habitat variation and trophic specialization have contributed to a large extent to the astonishing diversity of cichlid fishes in the Great East African lakes. Because parasite communities often vary across space and environments, parasites can accompany and potentially enhance cichlid species diversification. However, host dispersal may reduce opportunities for parasite-driven evolution by homogenizing parasite communities and allele frequencies of immunity genes. To test for the relationships between parasite community variation, host dispersal and parasite-induced host evolution, we studied two sympatric cichlid species with contrasting dispersal capacities along the shores of southern Lake Tanganyika. Whereas the philopatric Tropheus moorii evolved into several genetically differentiated colour morphs, Simochromis diagramma is phenotypically rather uniform across its distribution range and shows only weak population structure. Populations of both species were infected with divergent parasite communities and harbour differentiated variant pools of an important set of immune genes, the major histocompatibility complex (MHC). The overall extent of geographical variation of parasites and MHC genes was similar between host species. This indicates that immunogenetic divergence among populations of Lake Tanganyika cichlids can occur even in species that are strongly dispersing. However, because this also includes species that are phenotypically uniform, parasite-induced evolution may not represent a key factor underlying species diversification in this system.

• MeSH
• cichlidy genetika   imunologie   parazitologie   MeSH
• fenotyp MeSH
• hlavní histokompatibilní komplex genetika   MeSH
• imunogenetika * MeSH
• paraziti MeSH
• populační genetika MeSH
• rozšíření zvířat * MeSH
• sympatrie * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Tanzanie MeSH

In predators an ontogenetic trophic shift includes change from small to large prey of several different taxa. In myrmecophagous predators that are also mimics of ants, the ontogenetic trophic shift should be accompanied by a parallel mimetic change. Our aim was to test whether ant-eating jumping spider, Mexcala elegans, is myrmecomorphic throughout their ontogenetic development, and whether there is an ontogenetic shift in realised trophic niche and their mimetic models. We performed field observations on the association of Mexcala with ant species and investigated the natural prey of the ontogenetic classes by means of molecular methods. Then we measured the mimetic similarity of ontogenetic morphs to putative mimetic models. We found Mexcala is an inaccurate mimic of ants both in the juvenile and adult stages. During ontogenesis it shifts mimetic models. The mimetic similarity was rather superficial, so an average bird predator should distinguish spiders from ants based on colouration. The realised trophic niche was narrow, composed mainly of ants of different species. There was no significant difference in the prey composition between ontogenetic stages. Females were more stenophagous than juveniles. We conclude that Mexcala is an ant-eating specialist that reduces its prey spectrum and shifts ant models during ontogenesis.

• MeSH
• bio-ontologie MeSH
• biologická adaptace fyziologie   MeSH
• biologická evoluce MeSH
• ekosystém MeSH
• Formicidae MeSH
• mimikry fyziologie   MeSH
• pavouci metabolismus   fyziologie   MeSH
• predátorské chování fyziologie   MeSH
• selekce (genetika) genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH