RESUMO
Using nearly range-wide sampling, we analyze up to 1848 bp of mitochondrial DNA of 183 helmeted terrapins and identify a minimum of 12 deeply divergent species-level clades. Uncorrected p distances of these clades equal or clearly exceed those between the currently recognized species of Pelusios, the genus most closely related to Pelomedusa. We correlate genetic discontinuities of Pelomedusa with data on morphology and endoparasites and describe six new Pelomedusa species. Moreover, we restrict the name Pelomedusa subrufa (Bonnaterre, 1789) to one genetic lineage and resurrect three further species from its synonymy, namely P. galeata (Schoepff, 1792), P. gehafie (Rüppell, 1835), and P. olivacea (Schweigger, 1812). In addition to these ten Pelomedusa species, we identify two further clades from Cameroon and Sudan with similar levels of genetic divergence that remain unnamed candidate species. We also note that some problematical terrapins from South Africa and Somalia may represent two additional candidate species. Some of the Pelomedusa species are morphologically distinctive, whilst others can only be identified by molecular markers and are therefore morphologically cryptic taxa.
Assuntos
Biodiversidade , DNA Mitocondrial , Tartarugas/classificação , África Subsaariana , Animais , Feminino , Madagáscar , Masculino , Oriente Médio , Filogenia , Tartarugas/anatomia & histologia , Tartarugas/genéticaRESUMO
The genus Serpinema was erected from the genus Camallanus to include species parasitising freshwater turtles. Following this, the taxonomic status of Serpinema was challenged by different authors considering it as a subgenus or junior synonym of Camallanus. Several specimens of these nematodes were retrieved from the spot-legged wood turtle Rhinoclemmys punctularia from Cayenne, French Guiana. These specimens clearly differed from previously reported Serpinema and Camallanus species parasitising turtles by the number of caudal papillae, shape of spicules and development of vulvar lips. Based on morphological characters the nematodes were assigned to the genus Serpinema and described as a new species S. cayennensis n. sp. The description followed by the molecular data analyses based on 28S, 18S rDNA and cytochrome oxidase subunit 1 (COI) gene sequences.
Assuntos
Nematoides , Parasitos , Tartarugas , Animais , Guiana Francesa , Água Doce , Filogenia , Tartarugas/parasitologiaRESUMO
Rhabdias picardiae previously known from the Guttural Toad, Sclerophrys gutturalis (Bufonidae) is described from a new host, Delaland's River Frog, Amietia delalandii (Pyxicephalidae). The species identification is confirmed by analysis of the COI gene sequence and morphological comparison with the original description. Morphological details of apical structures in adult parasitic R. picardiae, namely, the shape and position of lips, the number and position of external labial papillae, and the buccal capsule morphology are described using light and scanning electron microscopy. The buccal capsule width and length, the distance from anterior end to nerve ring and excretory pore, and ratios of distance to vulva to body length and body length to width were identified as less variable metrical characters in the studied sample of 30 specimens. Adult specimens demonstrated differences in the position of lips in relation to the oral opening and position of the buccal capsule in relation to the oesophagus depending on the size (age) of worms. The infective larvae of R. picardiae are described for the first time and characterised by two lateral alae consisting of two ridges, triangular pseudolabia with rounded tops, and presence of ornamentation on the rounded tail tip.
Assuntos
Anuros/parasitologia , Tylenchida/anatomia & histologia , Tylenchida/genética , Estruturas Animais/anatomia & histologia , Animais , Biometria , Complexo IV da Cadeia de Transporte de Elétrons/genética , Microscopia , Microscopia Eletrônica de Varredura , Filogenia , Rios , Análise de Sequência de DNA , África do Sul , Tylenchida/classificação , Tylenchida/isolamento & purificaçãoRESUMO
Leaf-folding frogs of the genus Afrixalus comprise 33 species across South-East, Central and West Africa (Frost 2018) with tadpoles being described for Afrixalus aureus Pickersgill, A. delicatus Pickersgill, A. dorsalis (Peters), A. fornassinii (Bianconi), A. fulvovittatus (Cope), A. laevis (Ahl), A. morerei Dubois, A. nigeriensis Schiøtz, A. spinifrons (Cope), A. stuhlmanni (Pfeffer), A. uluguruensis (Barbour Loveridge), A. vibekensis Schiøtz, A. vittiger Peters, and A. weidholzi (Mertens) (see Pickersgill 2005; Channing et al. 2012). Members of the genus have a unique approach to egg deposition, laying their eggs on soft-leaved hydrophytes. The male folds or rolls the leaf with his hind legs into a sheath following oviposition and fertilisation (Rose 1950; Wager 1954; Du Preez Carruthers 2017), excreting an adhesive substance and enclosing the eggs within while the "glue" cures (Rose 1950, Wager 1954, authors pers. obs.).
Assuntos
Anuros , África Ocidental , Animais , Feminino , Larva , Masculino , Oviposição , ÓvuloRESUMO
The South African leech Marsupiobdella africana is a temporary ectoparasite of the amphibian Xenopus laevis, has a phoretic association with a freshwater crab Potamonautes perlatus, and exhibits advanced parental care by incubating its offspring in a brood pouch. Because phoretic associations are usually regarded to favor the phoront's dispersion, its occurrence within the biology of a parasitic species reflects an intimate context of interactions. In addition to phoresy, attachment to the crab may confer other advantages pertaining to offspring development and predator avoidance, dispersion and the parasitic life cycle. Two ponds where amphibian and crab hosts co-occur were sampled twice a month for a period of 1 year. The population dynamics of the leeches and their use of specific microhabitats as attachment sites on the crabs were also investigated. Results indicate a direct relationship between intra-specific variation in the sex ratio among captured crab hosts and the number of leeches recruited over time. The attachments to specific microhabitats on the hard surfaces of the host suggest a proximal proximate anti-predatory strategy. Finally, the importance of oxygen accessibility for the offspring development has been investigated experimentally. Results revealed a remarkable network of interactions linking all partners of this system raising the question as to whether the crabs merely act as a vehicle or play a role within the parasitic life cycle.