Caprella mutica (Crustacea, Amphipoda) has been widely introduced to non-native regions in the last 40 years. Its native habitat is sub-boreal northeast Asia, but in the Northern Hemisphere, it is now found on both coasts of North America, and North Atlantic coastlines of Europe. Direct sequencing of mitochondrial DNA (cytochrome c oxidase subunit I gene) was used to compare genetic variation i...

We examined functions of residual yolk (RY) in hatchling Smooth Softshell Turtles (Apalone mutica). Removal of RY did not affect survival, shell growth, or resting metabolic rates of turtles for 40 d after hatching. Our estimates of metabolic rate suggest that RY can fuel maintenance and activity metabolism for approximately 25 days. A. mutica absorb more than 1g of water in the first 2 weeks o...

An active filter feeding organism strains suspended matter from the surrounding water using a sieving structure. Small marine filter feeders however, have to cope with the physical problems of the high viscosity as indicated by the low Reynolds number. In a highly viscous regime, organisms' appendages are surrounded by a thick boundary layer, which makes movement and filter feeding difficult. I...

The endemic South African sac spider genus Lessertina Lawrence, 1942, previously known only from the type species (L. mutica Lawrence, 1942), is revised. Both sexes of L. mutica are redescribed and the species is recorded from the Eastern Cape, KwaZulu-Natal and Limpopo Provinces. A new species, L. capensis sp. nov., is described from the Eastern and Western Cape Provinces.

Sexual development has long been the target of study and despite great advances in our understanding of the composition and regulation of the gene network underlying gonadogenesis, our knowledge remains incomplete. Of particular interest is the relative role that the environment and the genome play in directing gonadal formation, especially the effect of environmental temperature in directing t...

The evolution of sex determination has long fascinated biologists, as it has paramount consequences for the evolution of a multitude of traits, from sex allocation to speciation and extinction. Explaining the diversity of sex-determining systems found in vertebrates (genotypic or GSD and temperature-dependent or TSD) requires a comprehensive and integrative examination from both a functional an...

The second largest BamHI fragment (B2) of the chloroplast DNA in Triticum (wheat) and Aegilops contains a highly variable region (a hotspot), resulting in four types of B2 of different size, i.e. B2l (10.5kb), B2m (10.2kb), B2 (9.6kb) and B2s (9.4kb). In order to gain a better understanding of the molecular nature of the variations in length and explain unexpected identity among B2 of Ae. ovata...