Over the last two decades my colleagues and I have assembled the literature on a good percentage of most of the coccidians (Conoidasida) known, to date, to parasitise: Amphibia, four major lineages of Reptilia (Amphisbaenia, Chelonia, Crocodylia, Serpentes), and seven major orders in the Mammalia (Carnivora, Chiroptera, Lagomorpha, Insectivora, Marsupialia, Primates, Scandentia). These vertebrates, combined, comprise about 15,225 species; only about 899 (5.8%) of them have been surveyed for coccidia and 1,946 apicomplexan valid species names or other forms are recorded in the literature. Based on these compilations and other factors, I extrapolated that there yet may be an additional 31,381 new apicomplexans still to be discovered in just these 12 vertebrate groups. Extending the concept to all of the other extant vertebrates on Earth; i.e. lizards (6,300 spp.), rodents plus 12 minor orders of mammals (3,180 spp.), birds (10,000 spp.), and fishes (33,000 spp.) and, conservatively assuming only two unique apicomplexan species per each vertebrate host species, I extrapolate and extend my prediction that we may eventually find 135,000 new apicomplexans that still need discovery and to be described in and from those vertebrates that have not yet been examined for them! Even doubling that number is a significant underestimation in my opinion.
Species–area relationships and nestedness patterns were studied in three groups of small terrestrial vertebrates (mammals, reptiles, amphibians) on 14 landbridge islands of the eastern Adriatic. Islands ranged in surface area between 15 and 410 km2 and contained from eight to 36 species from a total species pool of 48. Reptiles were the most species rich group (S = 28), and had more species than mammals (S = 13) and amphibians (S = 7) combined. Island surface area predicted species richness best in reptiles (r2 = 0.79) and most poorly in amphibians (r2 = 0.52). Mammals showed a significantly lower slope of the species–area curve than amphibians and reptiles, and thus accumulated species counts with increase in area at the lowest rate. Nestedness patterns in all groups were significantly more organised than expected by chance. Amphibian nested structure points to extinction dominated and well insularised populations with no subsequent recolonisations. Frequent unexpected presences and absences in the nestedness patterns of mammals and reptiles suggest complex biogeographic histories for these two groups, with several factors putatively in operation: heterogeneity in habitats and the original source fauna, post- isolation immigrations and differential extinction rate due to human-caused habitat degradation.
The highest altitude recorded for an amphibian in Europe (west of the Caucasus) is 2965 m. It refers to the "lacs de Cambalès" according to an old reference. However, these lakes are all situated below 2600 m, while the altitude corresponds exactly to that of the summit of the Pic de Cambalès. We undertook an almost complete survey of ponds in a 2.5 km radius from the Cambalès peak, and complemented these data by fieldwork in a larger portion of the Central Pyrenees. Based on our observations in a total of 325 lakes and ponds we conclude that no water bodies above 2800 m exist in the Cambalès area, and that no water bodies above 2600 m are populated by Rana temporaria. The highest amphibian record was that of a single R. temporaria specimen at 2569 m, while the highest reproducing population was found at 2516 m. Highest records of other amphibians were 2516 m (Alytes obstetricans), 2160 m (Bufo bufo), 2259 m (Euproctus asper), and 2142 m (Salamandra salamandra). The presence of ice-free water bodies during a sufficient amount of time for larval development is probably the limiting factor for elevational distribution of Pyrenean amphibians, and the adequate conditions are usually not met above 2500 m in this massif. In contrast, in the Alps, ponds at higher altitudes are often protected by much higher surrounding peaks, which leads to higher elevational occurrence of amphibians. The Italian Laghi di Tre Becchi (up to 2742 m) are therefore the highest locality of a reproducing anuran population in Europe west of the Caucasus.
A sample of over 6,000 specimens of frogs belonging to about 120 species of all families occurring in West Africa and Madagascar were screened for parasitic mites. Three species of Endotrombicula Ewing, 1931 were found in representatives of two African and two Madagascan frog families. All Trombiculidae found in African frogs belonged to Endotrombicula pillersi (Sambon, 1928), whereas in Madagascar E. madagascariensis (Sambon, 1928) and E. ptychadenae sp. n. were sampled. These three species are described, data about their parasitic associations are provided, and their zoogeographical distribution is discussed. Only those frog species that spend a considerable time in terrestrial ground habitats were parasitized; neither arboreal nor strictly aquatic frogs were infected. The geographic distribution of Endotrombicula, restricted to Africa, the Arabian Peninsula and Madagascar, suggests that these mites invaded Madagascar from the African continent. This is supported by the observation that the ancestors of Ptychadena mascareniensis (Duméril et Bibron) (Ptychadenidae), the host of E. ptychadenae, colonized Madagascar from the African continent quite recently, possibly accompanied by its Endotrombicula parasites.
The genus Maxvachonia Chabaud et Brygoo, 1960 (Ascaridomorpha: Cosmocercidae) is a poorly known group of parasitic nematodes. Species of Maxvachonia are native to Madagascar-Australo-Papuan Region, where they are known to parasitise frogs, snakes and skinks. Unfortunately, most of Maxvachonia species have been inadequately described. In the present study, we report the native species Maxvachonia chabaudi Mawson, 1972 from the intestine of the invasive marine toad Rhinella marina (Linnaeus) in Australia for the first time. We speculate that the marine toads infected with M. chabaudi are likely related to their eating skinks or the similarity in diet/habitat/ecology between the toad and the skinks. The detailed morphology of M. chabaudi was studied using light microscopy and, for the first time, scanning electron microscopy, based on the newly collected specimens. Some characters important for the specific diagnosis of M. chabaudi are reported for the first time, including each lip with distinct inner flanges, the location of vulva varying from anterior to posterior of the oesophageal bulb and the presence of single medio-ventral precloacal papilla. An identification key to the species of Maxvachonia is provided.
Blood smears prepared from the peripheral blood of 20 wild caught Amietia quecketti (Boulenger) from the North-West University Botanical Gardens, North West Province, South Africa, were examined for the presence of haemogregarines. A haemogregarine species comparative in morphology, host and geographical locality to that of Haemogregarina theileri Laveran, 1905 was detected. The original description of H. theileri was based solely on frog peripheral blood gamont stages. Later, further parasite stages, including trophozoites and merogonic liver stages, were recorded in a related Amietia sp. from equatorial Africa. This species was originally classified as a member of the genus Haemogregarina Danilewsky, 1885, but due to the close life cycle and morphological resemblance to those of Hepatozoon species, H. theileri was later transferred from Haemogregarina to Hepatozoon Miller, 1908. In the present study, meront and merozoite stages not described before, along with previously observed trophozoite, immature and mature gamont stages, are described from the peripheral blood of hosts. In addition, comparative phylogenetic analysis of the partial 18S rDNA sequence of Hepatozoon theileri to those of other haemogregarine species, including those of species of Hepatozoon and a Haemogregarina, support the taxonomic transfer of H. theileri to Hepatozoon, nesting H. theileri within a clade comprising species parasitising other amphibians. This is the first molecular and phylogenetic analysis of an African anuran species of Hepatozoon.
Data on external ultrastructure of myxospores and internal ultrastructure of advanced pseudoplasmodia and myxospores of topotypic samples of Sphaerospora ranae (Morelle, 1929) from Rana dalmatina Bonaparte are provided, together with in situ hybridisation results. In both frogs examined, the infection was restricted to renal tubules and corpuscles. The infection site restriction was confirmed by light and transmission electron microscopy, as well as by in situ hybridisation. In addition, large myxospore masses measuring up to 500 μm were detected in seminal vesicles. Only late-sporogonic stages, i.e. pseudoplasmodia harbouring immature and/or mature myxospores, were observed and analysed. Scanning electron microscopy revealed that spores have smooth surface with exception of posterior valvular bulges, which possess numerous outwards opening internal canals. As revealed by both scanning and transmission electron microscopy, the canals are continuous invaginations of the outer spore surface. Myxospores of S. ranae are characterised by the presence of two uninucleate sporoplasms, bilayered polar capsules, S/H-shaped polar filaments in transversal section and multilayered polar filament eversion pole plugging complex. Ultrastructural observations are discussed in the context of available data for other species of Sphaerospora sensu stricto and apparent synchronisation of myxospore shedding with a brief aquatic breeding phase of vertebrate intermediate host is highlighted.