Browsing by Author "Hess, Anthony Jacobus"

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    Genetic variation between two subspecies of Reedfrogs in the genus Hyperolius (Anura: Hyperoliidae)
    (University of the Western Cape, 1993) Hess, Anthony Jacobus; Hendricks, Denver
    The frog genus Hyperolius is the largest of 19 genera in the Hyperoliidae (Channing, 1939). The members of the genus display considerable morphological homogeneity with a diversity of dorsal colour patterns. The genus is endemic to Africa and is distributed throughout the wetlands south of the Sahara excluding the western plateau slopes and South African plateau. They are found in close proximity to water, on reeds, sedges and also on water-lily leaves (Iambiris, 1989). The South African forms are commonly referred to as reedfrogs (Passmore and Camrthers, 1979). The members of the genus bury themselves in the ground and under leaves during the dry season and emerge after the first rains (Iambiris, 1989). The eggs are laid in water, attached to waterplants, but certain species deposit eggs above the water level or between water-lily leaves (Lambiris, 1989). Characters that disqinguish the genus from other African genera are as follows: The pupil is horizontal to round; Vomerine teeth are absent; The fingers and toes are webbed; The oral disc is ventrally situated (Passmore and Camrthers, 1979).
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    "Genetic variation between two subspecies of reedfrogs in the genus Hyperolius (Anura: Hyperoliidae)"
    (University of the Western Cape, 1993) Hess, Anthony Jacobus; Hendricks, Denver
    H. m. broadleyi and H. m. verrucosus are not only different in terms of colour pattern, but distinct genetic differences were detected in restriction site maps of their ribosomal DNA. A sequence divergence value of 13,8% was found between the subspecies. This value exceeds the range recorded between separate species of the genus Rana, ie. 2,2 % between Rana pustulosa and Rana tarahumarae, and 10, 1 % between Rana pustulosa and Rana pipiens. The value of 13,8% between the subspecies is also in the same range as that found between was detected between samples from three different localities within the distribution range of H. m. verrucosus. The genetic data associated with the different colour patterns, suggests that H. m. broadleyi and H. m. verrucosus can be regarded as distinct species. However, a similar study should be performed to examine the genetic status of the subspecies forming the gradient along the east coast of southern Africa. Although the effect of concerted evolution (as discussed in Chapter 2) allows for small sample sizes it would be useful to examine a large number of individuals especially from the overlap zones to determine the extent of genetic heterozygosity and to determine if similar genetic differences (found between H. m. broadleyi and H. m. verrucosus) exist between the rest of the subspecies. The current study has shown that genetic evaluation of all the southern African H. marmoratus subspecies could have a positive impact on the taxonomy of this group of frogs which is still unresolved. This study has identified at least two species within the H. marmoratus complex and it is possible that more species exist within the group. Because of morphological homogeneity it will be difficult to use morphological characters, but more than one molecular technique can be utilized to verify results obtained with one technique.