New and unpublished distribution records are provided for 22 of the26 amphibian taxa (species and subspecies) known to occur in the Free State province of South Africa. Four of these taxa, namely Heleophryne natalensis, Bufo gariepensis nubicolus, Breviceps v. verrucosus and Tomopterna natalensis, were not recorded during an intensive survey of the region in the 1970s.
The 27 anuran species and subspecies presently known to occur in the Vernon Crookes Nature Reserve in southern Kwazulu-Natal represent 94% of all anuran species and subspecies found in the Kwazulu-Natal coastal region.
Namibia is the most arid country south of the Sahara, yet 45 species of anurans are known, and a further l5 are expected to be found there. The northern assemblage consists of highly water-dependent species in the Caprivi that originate from rich faunas in Angola, Zambia, Zimbabwe, Malawi, Mozambique and Zaire. The southern assemblage which is partially arid-adapted originates from the rich Namaqualand fauna as well as from the Orange River watershed.
Two subspecies of reedfrogs HyperoIius mamoratus broadleyi (eastern Zimbabwe) and Hyperolius mamoratus verrucosus (Tsitsikama area - Knysna) were analysed for variation in nuclear ribosomal DNA by mapping restriction endonucIease sites.
A population of Breviceps adspersus Peters was studied over a ten year period in Pietersburg, Northern Transvaal, South Africa. An analysis of the advertisement call and data pertaining to the breeding period, callsite, chorus organization, and subterranean eggchambers are presented.
Marked similarities exist between the flora and fauna of the arid southwestern and northeastern corners of Africa. Among amphibians, a tendency towards this distribution is shown by vicariating species of the Bufo vertebralis group, by the B. garmanilpseudogarmanilpoweri complex and by Tomopterna cryptotis. In all of these, greater taxonomic complexity is present in the south, and ranges include the moister southeast.
With its lymphoid organs thymus and spleen, its T and B cells with their specific receptors Ig and TCR.MHC class I and class II, the immune system of Xenopus is basically similar to that of mammals. Less complex, involving a smaller number of lymphocytes, and lacking both lymph nodes and germinal centers, the Xenopus immune system presents additional peculiarities that make it an attractive model to study the ontogeny of thc immune system
Anurans exhibit modes of fertilization which place them in a category between true aquatic and true internal fertilizers. Their fertilization environments range from aquatic to terrestrial. This study descriptionbes the sperm structure and ultrastructure of representatives of two groups of anurans. The ranines occupy fertilization environments within bodies of water (aquatic) and the African rhacophorids in a foam nest on a tree branch (terrestrial).