Navegando por Assunto "Larvas"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758) (Squamata: Teiidae)
(Universidade Federal do Pará, 2016-03) MACEDO, Lilian Cristina; MELO, Francisco Tiago de Vasconcelos; ÁVILA-PIRES, Teresa Cristina Sauer de; GIESE, Elane Guerreiro; SANTOS, Jeannie Nascimento dos
Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the “Osvaldo Rodrigues da Cunha” Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard.
Acesso aberto (Open Access)
Effects of environmental factors on community structure of Leptophlebiidae (Insecta, Ephemeroptera) in Cerrado streams, Brazil
(2013-09) BRASIL, Leandro Schlemmer; SHIMANO, Yulie; BATISTA, Joana Darc; CABETTE, Helena Soares Ramos
We analyzed the effects of environmental factors on abundance, species richness, and functional group richness of Leptophlebiidae in 16 sampling points along four Cerrado streams. Across three periods of 2005, we collected 5,492 larvae from 14 species in stream bed substrate. These species belong to three functional feeding groups: scrapers, filtering collectors and shredders. The abundance and species richness were not affected by water quality, but habitat quality related to presence of riparian vegetation had positive effects on the abundance of shredders. Our results add important information on the natural history of the species and functional groups of aquatic insects and also provide relevant data for the monitoring and conservation of streams in the Brazilian Cerrado.
Acesso aberto (Open Access)
Estrutura e composição da comunidade de Trichoptera (Insecta) de rios e áreas alagadas da bacia do rio Suiá-Miçú, Mato Grosso, Brasil
(2011-09) NOGUEIRA, Denis Silva; CABETTE, Helena Soares Ramos; JUEN, Leandro
The composition, abundance and species diversity of Trichoptera immatures was studied in 12 tributaries of Suiá-Miçú River Basin, a mosaic of wetlands, streams and rivers tributary of the Xingu River in the Cerrado-Amazonian Forest transition zone in Mato Grosso, Brazil. The varying sizes, flow types and conservation levels of the tributaries were sampled through three periods between 2007 and 2008 by the use of fixed transects along the environments margins. A total of 867 larvae was collected (divided in seven families, 17 genera, 49 species/morphospecies) with the most abundant and rich families being Hydropsychidae and Leptoceridae and the most abundant species Leptonema sparsum (n = 370). There has been loss of species richness in impacted, large and lentic environments. Composition variations related to the flow, the vegetation type and the interaction between conservation levels and flow was detected. Conservation levels, width and the quantitative habitat integrity index (HII) did not influence the Trichoptera composition. These results may encourage further investigation of impact effects on aquatic insect compositions and pattern of distribution in the transition area between the Cerrado and the Amazonian Forest.
Acesso aberto (Open Access)
Ontogenia do peixe de quatro olhos Anableps anableps: adaptações ósseas e oculares para a visão simultânea aérea e aquática
(Universidade Federal do Pará, 2015-09-30) PEREZ, Louise Neiva; SCHNEIDER, Patrícia Neiva Coelho; http://lattes.cnpq.br/9584217233879031
The evolution and development of the eye has intrigued developmental biologists for centuries. Aside from partial or complete loss, few vertebrates display substantial modifications to the eye morphology. One example is the Four-eyed fish (Anableps anableps). This species is commonly found from Gulf of Paria in Venezuela to Delta of Parnaíba and reproduces throughout the year. The four-eyed fish consists in a unique model system to study eye Evo-Devo due to its distinctive feature of having divided eye structures, such as pupils and cornea. The retina is a unique structure divided into two regions, dorsal (receives aquatic luminous information) and ventral (receives aerial luminous information). The aim of this study was to describe larval stages of this species, and morphological and molecular description of the retina during eye development. Six larval stages were described. The two earlier stages did not split the cornea and pupil, and from stage three, it is possible to observe this division. It was also described the development and expansion of the frontal bone. The appearance of the frontal bone begins at stage three of development. It has been identified the appearance of an inter-orbital septum cartilaginous, starting four stage of the ocular development. It was observed that the early development of the retinal cellular layers are disorganized and is not possible to distinguish between them, but later during development, these layers become organized, with ventral outer nuclear layer thicker than the dorsal one, and the dorsal inner nuclear layer is thinner than the ventral. The pattern of retinal cell proliferation has been described in three stages of development, before and during ocular division. It was observed that the proliferation is greater at the beginning of the larval development and decreases on later stages. The result of this study will shed light on the molecular basis of this innovative feature.