ABSTRACT
Microevolutionary processes in parasites are driven by factors related to parasite biology, host abundance and dispersal, and environmental conditions. Here, we test the prediction that isolation of host populations results in reduced genetic diversity and high differentiation among parasite populations. We conducted a population genetic analysis of two pinworms, Trypanoxyuris minutus and Trypanoxyuris atelis, commonly found parasitizing howler and spider monkeys in tropical rainforests across south-eastern Mexico, whose populations are currently isolated due to anthropogenic habitat loss and fragmentation. Mitochondrial DNA was employed to assess parasite genetic patterns, as well as to analyse their demography and population history. Both pinworm species showed high haplotype diversity but, unexpectedly, lower nucleotide diversity than that reported for other parasites. No genetic differentiation or population structure was detected in either pinworm species despite habitat loss, fragmentation and host isolation. Several scenarios are discussed that could help to explain the genetic panmixia found in both pinworm species, including higher than expected primate inter-fragment dispersal movements, and passive dispersal facilitating gene flow between parasite populations. The results suggest that large population sizes of parasites could be helping them to cope with the isolation and fragmentation of populations, delaying the effects of genetic drift. The present study highlights the complexity of the drivers that intervene in the evolutionary processes of parasites. Detailed genetic studies are needed, both in host and parasite populations, to assess the effects that habitat perturbation and environmental changes could have on the evolutionary dynamics of pinworms and primates.
Subject(s)
Alouatta/parasitology , Atelinae/parasitology , Monkey Diseases/parasitology , Oxyuriasis/veterinary , Oxyuroidea/genetics , Animals , Bayes Theorem , DNA, Helminth/chemistry , DNA, Mitochondrial/chemistry , Ecosystem , Feces/parasitology , Forests , Genetic Variation , Genetics, Population , Haplotypes , Host Specificity , Mexico , Oxyuriasis/parasitology , Oxyuroidea/isolation & purificationABSTRACT
This study reports on infection by Trypanoxyuris (Trypanoxyuris) minutus among Alouatta guariba clamitans through biometry on adults and eggs. A total of 58 adult helminths were recovered from the small segment of the animal's large intestine. This study is the first report of this parasite among A. guariba clamitans in Rio de Janeiro.
Subject(s)
Alouatta , Monkey Diseases/parasitology , Oxyurida Infections/veterinary , Oxyurida/anatomy & histology , Animals , Brazil , Female , Intestinal Diseases, Parasitic/parasitology , Intestinal Diseases, Parasitic/veterinary , Male , Oxyurida/isolation & purification , Oxyurida Infections/parasitologyABSTRACT
Syphacia (Seuratoxyuris) hugoti n. sp. (Nematoda: Oxyuridae) is described from the cecum of Sooretamys angouya (Cricetidae: Sigmodontinae: Oryzomyini) captured in Formosa Province, Argentina. The diagnosis of the subgenus is emended, and the new species is separated from eight congeners by the distribution of submedian papillae and amphids, shape of the cephalic plate, presence of deirids, absence of cervical and lateral alae, length of the spicule, structure of the accessory hook of the gubernaculum and distance of excretory pore and vulva from the anterior extremity. The analysis suggests that S. (Se.) oryzomyos should be removed from Seuratoxyuris and redesignated as S. (Syphacia) oryzomyos n. comb. To date, of the species of Syphacia found in South and North American, 7 parasitize Oryzomyini rodents, of which two are distributed in Argentina. The present study constitutes the first record of the subgenus Seuratoxyuris from Argentina and the third record of a Syphacia species from rodents of the tribe Oryzomyini.
Subject(s)
Arvicolinae/parasitology , Oxyuroidea/isolation & purification , Animals , Argentina , Cecum/parasitology , Female , Male , Oxyuroidea/anatomy & histology , Oxyuroidea/classificationABSTRACT
Steindachnerina brevipinna is a freshwater fish from the Curimatidae family,and its occurrence is restricted to some South American countries (Argentina, Brazil,Paraguay and Uruguay), distributed in the Paraguay, lower and upper Paraná and lowerUruguay rivers. There are no parasitological studies related to this fish. The present studyrecords and illustrates a species of digenean, Sphincterodiplostomum musculosum fromsubfamily Diplostominae, present on the ovary and three species of nematodes,Cosmoxynema vianai Travassos, 1949, Travnema travnema Pereira, 1938, Spinoxyuris sp., ofsuperfamily Oxyuridea, parasitizing the intestine of S. brevipinna collected in the tributariesGuairacá and Corvo of the Paranapanema River, Parana State, Brazil.
Steindachnerina brevipinna é um peixe dulcícola da família Curimatidae e suaocorrência é restrita a alguns países da América do Sul (Argentina, Brasil, Paraguai eUruguai) e estão distribuídos nos rios Paraguai, baixo e alto Paraná e baixo Uruguai. Aindanão existem estudos parasitológicos relacionados a esse peixe. No presente trabalho foramregistrados e ilustrados uma espécie de digêneo, Sphincterodiplostomum musculosum Dubois,1936 da subfamília Diplostominae presente no ovário e três espécies de nematodas,Cosmoxynema vianai Travassos, 1949, Travnema travnema Pereira, 1938 e Spinoxyuris sp.,pertencentes à superfamília Oxyuridea localizados no intestino, para os espécimes de S.brevipinna coletados nos tributários Corvo e Guairacá do rio Paranapanema, Estado doParaná, Brasil.