ABSTRACT
The Amphibia are considered the most threatened vertebrate class globally, yet in Brazil they are also one of the more diverse and species rich groups. Although, in recent years there has been strong focus on amphibian related research, their parasites have not received the same attention. In Brazil, only a single species of Hepatozoon, namely H. leptodactyli (Lesage, 1908) Pessoa, 1970, has been described from anuran hosts. The present study aimed to describe three new species of Hepatozoon parasitising Leptodactylus labyrinthicus and Leptodactylus latrans from Mato Grosso State, Brazil. From 66 anurans screened for haemogregarines, four belonging to the Leptodactylidae were found positive for species of Hepatozoon. Based on the morphological analysis of peripheral blood gamonts and spleen and liver tissue meronts, three different morphotypes of Hepatozoon spp. were identified. Morphotype 1 (M1) and morphotype 2 (M2) in L. labyrinthicus and morphotype 3 (M3) in L. latrans. Molecular data based on partial 18S rDNA sequences revealed an interspecific divergence, between the species ranging from 0.43% to 1.16%. Phylogenetic analysis recovered isolates from the present study monophyletic with other isolates from Brazilian reptile and anuran hosts, sister to a clade comprising species isolated from African, North American and European reptile and anuran host species. Thus, using morphological and molecular analysis three new species infecting Brazilian Leptodactylidae anurans were identified and described. This study increases the knowledge of Brazilian anurans blood parasites and demonstrates the importance of using integrative approaches for diagnosis of hemoparasites.
ABSTRACT
Understanding the effects of atrazine exposure on embryo development in oviparous animals may provide important data regarding the impacts of agrochemical use on wildlife and the ecosystem. This study set out to determine the effects of embryonic atrazine exposure on the development of osseous and cartilaginous components of scleral ossicles in Podocnemis expansa. Eggs were collected at the Environmental Protection Area Meandros do Rio Araguaia, Brazil, and artificially incubated in sand treated with solutions containing 2, 20 or 200 µg/L of atrazine. Sixty embryos were collected per treatment throughout the incubation period. Embryos were diaphanized with potassium hydroxide (KOH) and stained with Alizarin Red S and Alcian blue (bone and cartilage tissue respectively). Scleral ossicles were then counted and examined for skeletal abnormalities at different stages of embryonic development. Scleral ossicle counts were significantly reduced in P. expansa embryos treated with 200 µg/L atrazine solution. Rudimentary ossicles and gaps were also noted in embryos exposed to atrazine concentrations of 2 µg/L or 200 µg/L. Findings of this study emphasize the relevance of ecotoxicological investigations in determining the impacts of agrochemicals on native fauna.
Subject(s)
Atrazine/toxicity , Environmental Exposure/adverse effects , Herbicides/toxicity , Animals , Atrazine/administration & dosage , Brazil , Dose-Response Relationship, Drug , Herbicides/administration & dosage , Sclera/drug effects , Sclera/embryology , Turtles/embryologyABSTRACT
The Dactylosomatidae Jakowska and Negrelli, 1955 are one of four families belonging to adeleorinid coccidia and comprise the genera Babesiosoma Jakowska and Nigrelli, 1956 and Dactylosoma Labbé, 1894. These blood protozoa occur in peripheral blood of lower vertebrates, and are commonly reported parasitising amphibians. The present study describes Dactylosoma piperis n. sp. from the pepper frog Leptodactylus labyrinthicus (Spix, 1824) (Anura: Leptodactylidae), collected in 2018 at the municipality of Araguaiana, Mato Grosso State, Brazil, based on morphology of intra-erythrocytic trophozoite, primary and secondary merogonic stages and a molecular analysis (partial 18S rDNA). Dactylosoma piperis n. sp. forms a well-supported clade with other Dactylosomatidae. This is the first molecular characterization of a species of Dactylosoma from a Brazilian anuran.
TITLE: Une nouvelle espèce, Dactylosoma piperis n. sp. (Apicomplexa, Dactylosomatidae), parasite de la grenouille Leptodactylus labyrinthicus (Anura, Leptodactylidae) de l'état du Mato Grosso, Brésil. ABSTRACT: Les Dactylosomatidae Jakowska et Negrelli, 1955 sont l'une des quatre familles appartenant aux coccidies Adeleorina et comprennent les genres Babesiosoma Jakowska et Nigrelli, 1956 et Dactylosoma Labbé, 1894. Ces protozoaires sanguins se trouvent dans le sang périphérique des vertébrés inférieurs et sont fréquemment signalés comme parasitant des amphibiens. Ce travail décrit Dactylosoma piperis n. sp. de la grenouille Leptodactylus labyrinthicus (Spix, 1824) (Anura : Leptodactylidae), collectée en 2018 dans la municipalité d'Araguaiana, État du Mato Grosso, Brésil, d'après la morphologie du trophozoïte intra-érythrocytaire, des stades mérogoniques primaires et secondaires et une analyse moléculaire (ADNr 18S partiel). Dactylosoma piperis n. sp. forme un clade bien soutenu avec d'autres Dactylosomatidae. Il s'agit de la première caractérisation moléculaire d'une espèce de Dactylosoma à partir d'un anoure brésilien.
