Nematode Parasites of Vertebrates: Their Development and Transmission

Fil: Vaira, Marcos. Universidad Nacional de Jujuy. Facultad de Ingenieria. Centro de Investigaciones Basicas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina

/pdf/categorizacion-del-estado-de-conservacion-de-los-anfibios-de-1trwo2y5p8.pdf

Categorización del estado de conservación de los anfibios de la República Argentina

Parasitological studies on helminths of amphibians in South America have increased in the past few years. Here, we present a list with summarized data published on helminths of South American amphibians from 1925 to 2012, including a list of helminth parasites, host species, and geographic records. We found 194 reports of helminths parasitizing 185 amphibian species from eleven countries: Argentina, Brazil, Chile, Colombia, Equador, French Guyana, Guyana, Paraguay, Peru, Uruguay and Venezuela. Helminth biodiversity includes 278 parasite species of the groups Acanthocephala, Nematoda, Cestoda, Monogenea and Trematoda. A list of helminth parasite species per host, and references are also presented. This contribution aims to document the biodiversity of helminth parasites in South American amphibians, as well as identify gaps in our knowledge, which in turn may guide subsequent studies.

/pdf/checklist-of-helminth-parasites-of-amphibians-from-south-3np9x665wg.pdf

Checklist of Helminth parasites of Amphibians from South America.

One hundred seventy-two frogs (Leptodactylus chaquensis) were collected from November 2002 to November 2003, in agricultural (n = 132) and nonagricultural (n = 40) areas. Both sites are near the city of Corrientes, Argentina. The main goals of this study were as follows: (1) to determine the helminth parasite community in agricultural and nonagricultural habitats; (2) to analyze the relationships between helminth parasites and site of infection, frog body size, and gender; (3) to identify and examine covariation and association of helminth communities; and (4) to determine the mean richness and diversity of parasite communities. The helminth compound community of this amphibian species consisted of 24 species: 19 in agricultural habitats and 18 in nonagricultural habitats. The mean richness, mean diversity, and evenness of helminths were significantly different between the habitats (P < 0.05). The body size of the host was the important factor in determining parasite richness. Both habitats exhibited differences in community ordination. The helminth species in the 2 habitats exhibited the same interspecific relationships, although differences were observed in the intensity of infection.

https://www.jstor.org/stable/pdfplus/40058651.pdf

Species affinity and infracommunity ordination of helminths of leptodactylus chaquensis (anura: leptodactylidae) in two contrasting environments from northeastern argentina

Activity of B-esterases (BChE: butyrylcholinesterase and CbE: carboxylesterase using two model substrates: α-naphthyl acetate and 4-nitrophenyl valerate) in a native frog, Leptodactylus chaquensis from rice fields (RF1: methamidophos and RF2: cypermethrin and endosulfan sprayed by aircraft) and non-contaminated area (pristine forest) was measured The ability of pyridine-2-aldoxime methochloride (2-PAM) to reactivate BChE levels was also explored In addition, changes in blood cell morphology and parasite infection were determined Mean values of plasma BChE activities were lower in samples from the two rice fields than in those from the reference site CbE (4-nitrophenyl valerate) levels varied in the three sites studied, being highest in RF1 Frog plasma from RF1 showed positive reactivation of BChE activity after incubation with 2-PAM Blood parameters of frogs from RF2 revealed morphological alterations (anisochromasia and immature erythrocytes frequency) Moreover, a major infection of protozoan Trypanosoma sp in individuals from the two rice fields was detected We suggest that integrated use of several biomarkers (BChE and CBEs, chemical reactivation of plasma with 2-PAM, and blood cell parameters) may be a promising procedure for use in biomonitoring programmes to diagnose pesticide exposure of wild populations of this frog and other native anuran species in Argentina

B-esterase activities and blood cell morphology in the frog Leptodactylus chaquensis (Amphibia: Leptodactylidae) on rice agroecosystems from Santa Fe Province (Argentina)

Niche overlap and resource partitioning among five sympatric bufonids (Anura, Bufonidae) from northeastern Argentina. The niche overlap and resource partitioning were analyzed for five sympatric bufonids from Northeastern Argenti- na: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa, and Melanophryniscus cupreuscapularis. The primary objectives were to analyze the diet and pattern of coexistence relative to the microhabitats among species. The bufonids, which are primarily terrestrial, exhibited a preference for small, hard prey such as formicids or coleopterans. The smallest species preferably consumed ants, while R. schneideri preferred beetles. Significant differences were detected for the diets of these five species. In addition, significant overlap in the trophic niche was noted for all species except between R. granulosa and R. schneideri. Studying the diet behaviors and trophic parameters of sympatric species provides important data for understanding the community and for the development of conservation guidelines.

/pdf/niche-overlap-and-resource-partitioning-among-five-sympatric-8q0vp5e5zb.pdf

Niche overlap and resource partitioning among five sympatric bufonids (Anura, Bufonidae) from northeastern Argentina

We studied the trophic and reproductive ecology and document the helminth fauna of the Cei's white-lipped frog, Leptodactylus chaquensis, from north-eastern Argentina. This frog is a generalist predator, using an intermediate strategy between active foraging and sit and wait predation. The diet consisted of 17 types of prey and was dominated numerically and volumetrically by coleopterans. The number of mature ova per female (ovarian complement) ranged from 3113 to 16234, and the ovum diameter varied from 0.4 to 1.2 mm. The testes mass ranged from 0.32 to 1.54 g, and the species has an explosive reproductive pattern. The parasite fauna was rich, consisting of 20 species of helminths (twelve trematodes, one cestodes, six nematodes and one acanthocephalan), the kidneys, lungs and large intestine being the organs most infected. The trophic niche breadth and the habitats where this species is living structured the parasite community.

Trophic, reproductive and parasitological aspects of the ecology of Leptodactylus chaquensis (Anura: Leptodactylidae) in Argentina

The main objectives of this paper were to update the distribution range of Pseudopaludicola boliviana in Argentina, to determine its diet composition and the feeding patterns, to analyze some reproductive variables as mature ova count and diameter in relation to female snoutvent length, to describe the advertisement call for Argentinean populations, and to identify and to localize its helminth parasites. Eleven prey types were identified; dipterans were more important both in number (23.53%) and in volume (41.30%); other important preys were collembolans, arachnids and coleopterans. The trophic niche width was 7.15 and the standardized trophic niche value was 0.61. Ovarian complement (number of mature ova for female) ranged from 50 to 319 (mean 175.3 ± 86.12), while ovum diameter ranged from 0.2 to 0.4 mm (mean 0.27 ± 0.062). The nuptial call is composed by five notes. The dominant frequency ranged from 3.488 to 5.927 kHz; emphasized frequency fluctuated between 4.942 and 5.224 kHz. A total of 10 helminth species (larvae and adults) were found in 54 (96%) infected frogs. Helminths were represented by Trematoda (7 species), Cestoda (1), Nematoda (1), and Acanthocephala (1).

/pdf/ecological-aspects-of-diet-reproduction-and-parasitism-of-3hrfg5pl87.pdf

Ecological aspects of diet, reproduction, and parasitism of Pseudopaludicola boliviana (Anura, Leptodactylidae) from Corrientes, Argentina

The anuran biodiversity and richness of a frog community inhabiting rice fields in northeastern Argentina was surveyed and analyzed. The samples were taken...

Diversity of amphibians in rice fields from northeastern argentina

This communication provides notes on 2 species of toads, Chaunus schneideri and Chaunus granulosus, infested with ixodid ticks, Amblyomma rotundatum, from the provinces of Corrientes and Formosa in northern Argentina. Chaunus schneideri is a new amphibian host record for A. rotundatum, a species previously reported to parasitize other anurans and also reptiles. We examined 74 ticks on 5 toads. All ticks were A. rotundatum; all adults were females, and all developmental stages were randomly attached to host body parts. Ticks remained attached to one of the toads for from 7 to 17 days after the host was captured. One toad, encumbered with 33 ticks, was moribund when found and died shortly thereafter.

https://bioone.org/journals/journal-of-parasitology/volume-94/issue-2/GE-1271.1/Ticks-Amblyomma-rotundatum-Acari--Ixodidae-on-Toads-Chaunus-schneideri/10.1645/GE-1271.1.pdf

Eduardo Federico Schaefer

Papers

Niche overlap and resource partitioning among five sympatric bufonids (Anura, Bufonidae) from northeastern Argentina

Trophic, reproductive and parasitological aspects of the ecology of Leptodactylus chaquensis (Anura: Leptodactylidae) in Argentina

Ecological aspects of diet, reproduction, and parasitism of Pseudopaludicola boliviana (Anura, Leptodactylidae) from Corrientes, Argentina

Diversity of amphibians in rice fields from northeastern argentina

Ticks, Amblyomma rotundatum (Acari: Ixodidae), on Toads, Chaunus schneideri and Chaunus granulosus (Anura: Bufonidae), in Northern Argentina