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Background: African annual killifishes (Nothobranchius spp.) are adapted to seasonally desiccating habitats (ephemeral pools), surviving dry periods as dormant eggs. Given their peculiar life history, geographic aspects of their diversity uniquely combine patterns typical for freshwater taxa (river basin structure and elevation gradient) and terrestrial animals (rivers acting as major dispersal barriers). However, our current knowledge on fine-scale interspecific and intra-specific genetic diversity of African annual fish is limited to a single, particularly dry region of their distribution (subtropical Mozambique). Using a widespread annual killifish from coastal Tanzania and Kenya, we tested whether the same pattern of genetic divergence pertains to a wet equatorial region in the centre of Nothobranchius distribution. Results: In populations of Nothobranchius melanospilus species group across its range, we genotyped a part of mitochondrial cytochrome oxidase subunit 1 (COI) gene (83 individuals from 22 populations) and 10 nuclear microsatellite markers (251 individuals from 16 populations). We found five lineages with a clear phylogeographic structure but frequent secondary contact. Mitochondrial lineages were largely congruent with main population genetic clusters identified on microsatellite markers. In the upper Wami basin, populations are isolated as a putative Nothobranchius prognathus, but include also a population from a periphery of the middle Ruvu basin. Other four lineages (including putative Nothobranchius kwalensis) coexisted in secondary contact zones, but possessed clear spatial pattern. Main river channels did not form apparent barriers to dispersal. The most widespread lineage had strong signal of recent population expansion. Conclusions: We conclude that dispersal of a Nothobranchius species from a wet part of the genus distribution (tropical lowland) is not constrained by main river channels and closely related lineages frequently coexist in secondary contact zones. We also demonstrate contemporary connection between the Ruvu and Rufiji river basins. Our data do not provide genetic support for existence of recently described cryptic species from N. melanospilus complex, but cannot resolve this issue.

Abstract. Body measurements of 110 beef cows of 9 breeds (Hungarian Simmental, Hereford, Aberdeen Angus, Red Angus, Lincoln Red, Shaver, Charolais, Limousin and Blonde d’Aquitaine) were taken in December 2004. The absolute, relative measurements and measurement indices moreover correlations between age, live weight and measurements were evaluated and compared for the mentioned breeds. Animals in study were born between 1989 and 2002, kept on the same condition on peat-bog soil pasture at Keszthely. Significant differences (P<0.05) were found among breeds in most of the body measurements. Blonde d’ Aquitaine was the heaviest in live weight (638 kg), highest as for the height at withers (142.5 cm), height at rump (146.6 cm) and length of the body (151.5 cm). Limousin had longest measurements as for the length of the rump (47.4 cm) and width of the rump (58.3 cm). Shaver had the longest width between shoulders (52.9 cm) and width of the head (25.1 cm) while Lincoln Red the longest length of the head (52.8 cm). The correlations between live weight and measurements were medium or strong positive (r = 0.40–0.83), between age and measurements slight positive (r = 0.01–0.46), among the different measurements medium or strong positive (r = 0.22–0.81).

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Karyotypes of two species of the African annual killifish genus Nothobranchius Peters, 1868, Nothobranchius brieni Poll, 1938 and Nothobranchius sp. from Kasenga (D.R. Congo) are described. Both species displayed diploid chromosome number 2n = 49/50 for males and females respectively with multiple-sex chromosome system type X1X2Y/X1X1X2X2. The karyotypes of studied species are considerably different from those previously reported for the genus Nothobranchius and similar to the Actinopterygii conservative karyotype.

The karyotype differentiation of the twelve known members of the Nothobranchius ugandensis Wildekamp, 1994 species group is reviewed and the karyotype composition of seven of its species is described herein for the first time using a conventional cytogenetic protocol. Changes in the architecture of eukaryotic genomes often have a major impact on processes underlying reproductive isolation, adaptation and diversification. African annual killifishes of the genus Nothobranchius Peters, 1868 (Teleostei: Nothobranchiidae), which are adapted to an extreme environment of ephemeral wetland pools in African savannahs, feature extensive karyotype evolution in small, isolated populations and thus are suitable models for studying the interplay between karyotype change and species evolution. The present investigation reveals a highly conserved diploid chromosome number (2n = 36) but a variable number of chromosomal arms (46–64) among members of the N. ugandensis species group, implying a significant role of pericentric inversions and/or other types of centromeric shift in the karyotype evolution of the group. When superimposed onto a phylogenetic tree based on molecular analyses of two mitochondrial genes the cytogenetic characteristics did not show any correlation with the phylogenetic relationships within the lineage. While karyotypes of many other Nothobranchius spp. studied to date diversified mainly via chromosome fusions and fissions, the N. ugandensis species group maintains stable 2n and the karyotype differentiation seems to be constrained to intrachromosomal rearrangements. Possible reasons for this difference in the trajectory of karyotype differentiation are discussed. While genetic drift seems to be a major factor in the fixation of chromosome rearrangements in Nothobranchius, future studies are needed to assess the impact of predicted multiple inversions on the genome evolution and species diversification within the N. ugandensis species group.

1. The small and colourful Nothobranchius fishes inhabit ephemeral habitats in freshwater wetlands of Africa and have extreme life-history adaptations that allow their eggs to survive the periodic drying up of the seasonal natural habitats.They are subject to high levels of threat, with 72% of the 94 assessed species falling into one of the threatened Red List categories, as a consequence of habitat degradation of seasonal wetlands. There is, therefore, a need to conserve ephemeral waters for species that rely on the seasonality of habitats.2. Extinction risk factors for all species of the genus were entirely reworked with IUCN Red List assessments, whereas first-time assessments were established for species that had previously not been evaluated. These fishes complete their

Commentary and discussion on a recent paper promoting the use of Nothobranchius guentheri, a small African annual fish from the Island of Zanzibar as a tool to control mosquito larvae in temporary bodies of freshwater throughout Africa is presented.Arguments on major points; (1) expected low success of annual fish introductions, (2) low success of mosquito control in the field, (3) ecological threats, and (4) ethical issues are detailed.Despite serious problems with mosquito-borne diseases in tropical Africa and elsewhere, we encourage responsible means of biological control of parasite vectors. We show that effectiveness of Nothobranchius translocations is low (the previous attempts failed), likelihood of effective mosquito larvae control under field condition is negligible and ecological threats from Nothobranchius translocations from within and outside the naturally occurring range are serious. We advocate against the proposed next step of the project, i.e. field trials in Tanzania.