RESUMEN
Hemipenes are important structures for the systematics of Squamata, and may assist in the diagnosis of closely related taxa. Only one of the species of Glaucomastix (G. venetacauda) had its hemipenial morphology described in literature so far. Here we analyze and describe for the first time the hemipenes of seven specimens of G. abaetensis and 20 specimens of G. littoralis from the reptile collection of Museu Nacional, Universidade Federal do Rio de Janeiro. In both species the hemipenes are bilobed with a forked sulcus spermaticus in a centripetal orientation and present laminar ornamentations on the hemipenial body and paired awns on the apical region of the lobes. The two species differed from each other only in the modal number of proximal laminae. The main differences in hemipenial morphology between Glaucomastix and its sister genus Ameivula are the presence of laminae in the hemipenial body (absent in Ameivula) and the absence of digitiform papillae on the apical lobular region (present in Ameivula). We expect that our data can be used as an additional tool to diagnose species within the genus Glaucomastix/Ameivula.
Asunto(s)
Lagartos , Animales , Lagartos/anatomía & histología , Lagartos/clasificación , Masculino , Femenino , Especificidad de la Especie , BrasilRESUMEN
We analyzed some reproductive aspects of 16 coastal populations, belonging to five lizard species (A. ocellifera, A. abaetensis, A. nativo, A. littoralis and C. lacertoides) from different restinga habitats along the eastern coast of Brazil. This study aimed to evaluate to what extent the reproductive aspects vary geographically and among species. For each female, we recorded the number of vitellogenic follicles, size and color of the largest follicle, presence and size of corpora lutea, and number and size of oviductal eggs. Clutch size of almost all coastal populations/species of Ameivula had little variation and most clutches were composed of two eggs. There was a significant relationship between female size and the mean clutch size when females from different species were pooled. Mean egg volume, among species, varied from 420 to 655 mm3. Relative clutch mass varied from 0.129 to 0.159 and did not differ significantly among species. We concluded that the five coastal species studied (four bisexuals and one parthenogenetic) had similar reproductive characteristics. Most of them presented multiple clutches, low clutch size and low relative clutch mass, similar to other species in the genus and to unisexual and bisexual species of the Teiidae family.
RESUMEN
We present data on species composition, relative abundance and estimated densities for leaf-litter anuran amphibians from an Atlantic Forest area within the Parque Estadual do Desengano, in the state of Rio de Janeiro, Brazil, based on results of a short-term survey carried out during the winter at altitudes of 1000-1500 m. Three sampling methods were used: plot sampling, visual encounter surveys (VES; performed during the day, at the twilight, and at night), and pitfall traps. We recorded 13 species, with the direct-developer Ischnocnema parva (Girard, 1853) being the most abundant. Most frogs (ca. 90% of all individuals) sampled by VES were captured during the crepuscular and nocturnal periods. The estimated density of the local leaf-litter frog assemblage based on plot sampling was 13.2 ind.100 m-2, which is one of the highest values currently reported for Atlantic Rainforest areas. This is the first study analyzing the anuran fauna of the Parque Estadual do Desengano and adds to the knowledge of the fauna of the northern region of the state of Rio de Janeiro, which is still poorly studied.
Apresentamos dados sobre a composição de espécies, abundância relativa e densidade estimada para anfíbios anuros de serrapilheira de uma área de Mata Atlântica no Parque Estadual do Desengano, no Estado do Rio de Janeiro, Brasil, com base em resultados de um estudo de curto prazo realizado durante o inverno a altitudes de 1000-1500 m. Três métodos de amostragem foram utilizados: amostragem em parcelas, encontros visuais (realizados durante o dia, no crepúsculo e à noite) e armadilhas de queda. Foram registradas 13 espécies, com Ischnocnema parva (Girard, 1853), uma forma com desenvolvimento direto, sendo a mais abundante. A maioria dos anuros (ca. 90% de todos os indivíduos) amostrados pelo método de encontros visuais foi coletada durante os períodos crepuscular e noturno. A densidade estimada para anuros de serrapilheira foi de 13,2 ind.100 m-2, que é um dos valores mais altos atualmente registrados para áreas de Mata Atlântica. Este é o primeiro estudo que analisa a fauna de anuros do Parque Estadual do Desengano e contribui para o conhecimento da fauna da região norte do estado do Rio de Janeiro, que ainda é pouco estudada.
RESUMEN
Host-choice experiments were carried out with rodent and bat ectoparasites on Ilha Grande, state of Rio de Janeiro, Brazil. We constructed experimental chambers that enclosed three different rodent or bat host species, and then introduced a selected set of ectoparasitic arthropods. When given the opportunity to choose among host species, the ectoparasites showed a strong tendency to select their primary hosts, and reject novel host species. These kinds of simple experiments can be valuable tools for assessing the ability of ectoparasites to locate and discern differences between host species, and make choices about which hosts to infest, and which hosts to avoid.
Asunto(s)
Artrópodos/fisiología , Quirópteros/parasitología , Conducta de Elección/fisiología , Roedores/parasitología , Animales , Interacciones Huésped-Parásitos/fisiologíaRESUMEN
Host-choice experiments were carried out with rodent and bat ectoparasites on Ilha Grande, state of Rio de Janeiro, Brazil. We constructed experimental chambers that enclosed three different rodent or bat host species, and then introduced a selected set of ectoparasitic arthropods. When given the opportunity to choose among host species, the ectoparasites showed a strong tendency to select their primary hosts, and reject novel host species. These kinds of simple experiments can be valuable tools for assessing the ability of ectoparasites to locate and discern differences between host species, and make choices about which hosts to infest, and which hosts to avoid.
Asunto(s)
Animales , Artrópodos/fisiología , Conducta Animal/fisiología , Quirópteros/parasitología , Conducta de Elección/fisiología , Roedores/parasitología , Interacciones Huésped-Parásitos/fisiologíaRESUMEN
Estudamos o comportamento de termorregulação e uso do habitat do lagarto teídeo partenogenético Cnemidophorus nativo e o efeito de variáveis ambientais na regulação de sua temperatura corpórea, na Restinga de Guaratiba, Prado, Bahia. Os lagartos foram coletados mensalmente, sendo medidas: a temperatura da cloaca [Tb], a temperatura do ar [Ta] e temperatura do substrato [Ts] com um termômetro cloacal Schultheis [precisão de 0,2°C], sendo registrado o microhabitat de cada lagarto. Cnemidophorus nativo em Guaratiba possui Tb de 39,0+2,0°C [31-42°C]. A relação entre a Tb e Ta foi significativa [F= 24,211,86; R2= 0,220; p<0,001], assim como a relação entre Tb e Ts [F = 27,401,51; R2 = 0,35; p<0,001]. A Tb não estava relacionada com o comprimento rostro-anal [F=3,131,95; R2 =0,032; p=0,08]. A Tb diferiu significativamente entre as estações [p=0,008] indicando que variações nas temperaturas ambientais afetam a Tb da espécie. Cnemidophorus nativo é uma espécie diurna com Tb relativamente elevada, necessária para manter a sua elevada taxa de movimentação. Os dados indicaram que Ta e Ts interagem para influenciar a Tb e ambas explicam apenas uma pequena parte da Tb o que é esperado para forrageadores ativos que se deslocam continuamente [AU]