Navegando por Assunto "Molusco"

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Acesso aberto (Open Access)
Aspectos ultraestruturais do espermatozóide de Natica marochiensish (Gmelin) (Mollusca, Gastropoda) do litoral norte do Brasil
(1997-09) MATOS, Edilson Rodrigues; MATOS, Patrícia Santos; CASAL, Graça Maria Figueiredo; AZEVEDO, Carlos José Correia de
Spermatozoa of Natica marochienssish (Gmelin, 1791) is described by light and electron microscopy. The spermatozoon is of the primitive type with head contains a conical acrosomal complex with an acrosomal vesicle of dense matrix having a basis occupied by the subacrosomal space. The middle piece shows the centriolar complex surrounded by mitochondria and the tail contains the axoneme with a 9+2.
Acesso aberto (Open Access)
Avaliação e comparação de projetos comunitários de ostreicultura localizados no nordeste paraense
(Universidade Federal do Pará, 2009) HOSHINO, Priscila; MCGRATH, David Gibbs; http://lattes.cnpq.br/4373475491613670
The aquaculture is being characterized as strategy to minimize the reduction of the fish. At Pará, the oyster farming was implanted in 2003 as an opportunity regarding to occupation and profits generation at Northeastern of this state. In 2005 this initiative was expanded to other communities with different levels of familiarity with the mollusk, regarding to the support either on the researches in this sector or on the extractive activity. This research evaluated the communitarian oyster farming performance in the state of Pará. It was studied three projects with at least two years of implementation and with either different levels of preservation and oyster harvest activity. The implementation of the firsts cultivations occurred simultaneously and in a similar way regarding to institutional support, however with different performances. The main producer issues are to obtain the license to develop this activity and also the necessity to take care about the tide. It is necessary to provide more detailed feasibility studies, with more commitment from the side of the interested institutions in order to perform the actions they are supposed to work out, providing events where it will be possible to spread the information and discuss the aquaculture bottlenecks at the state of Pará, as well to provide a consolidated partners network to prepare the groups regarding to organization, activity management and helping in the market access. The most part of the oyster famers are small producers, artisanal fishermen that found a way to manage their families via oyster farming. However, the oyster farming is a secondary activity to them, once it is still not enough to support their necessities. Nevertheless, several farmers already declared once they manage how to increase the oyster production they will be exclusively dedicated to this activity.
Acesso aberto (Open Access)
Diversidade e distribuição do gênero Alvania (Mollusca, Gastropoda: Rissoidae) no litoral brasileiro
(Universidade Federal do Pará, 2012-04-13) SILVA, Luciana Soares da; SANTOS, Franklin Noel dos; http://lattes.cnpq.br/2437036625902034; VENEKEY, Virág; http://lattes.cnpq.br/1106411624280455
The Rissoidae Gray, 1847 are composed of small shells or micro-shells, abundant in the oceans of the world. A great diversity of species of this group is found in areas of low tide and along the coast, where there is a higher occurrence of algae, rocks, corals and other places that provide shelter, however, they also occur in many areas of the deep sea. In Rissoidae, Alvania is one of the most diverse concerning species number with frequent descriptions or re-descriptions within this genus. The aim of this study was to determine the diversity and distribution of Alvania, therefore, describe and expand the knowledge of the fauna in Brazilian littoral, through conquiological analyses, beyond the geographical and bathymetric distribution of the species of this genus. All material is originated from collections of museums, oceanographic expeditions and also material collected in the second half of 2010 and in 2011. Previously, seven species were listed for the west cost of the Atlantic, and in the present study three of these species were not found. We analyzed 3599 specimens belonging to ten species: Alvania auberiana (Orbigny, 1842); Alvania cancapae Bouchet & Warén, 1993; Alvania colombiana Rommer & Moore, 1988; Alvania faberi De Jong & Coomans, 1988; Alvania tarsodes (Watson, 1886), Alvania valeriae Absalão, 1993 and four possible new species: Alvania sp. nov. 1, Alvania sp. nov. 2, Alvania sp. nov. 3, Alvania sp. nov.4.
Acesso aberto (Open Access)
Estrutura fina do espermatozóide de Tagelus plebeius (Lightfoot) (Mollusca, Bivalvia) do litoral norte do Brasil
(1997-09) MATOS, Edilson Rodrigues; MATOS, Patrícia Santos; CASAL, Graça Maria Figueiredo; AZEVEDO, Carlos José Correia de
It is described the sperm ultraestructure differentiation during spermiogenesis of Tagelus plebeius (Lightfoot, 1786). The spermatozoon is an uniflagellated cell of the primitive type. The head region contains a rounded or conical nucleus surrounded by acrosome. The middle piece contains four mitochondria which are arranged around the axoneme. The flagellum contains the usual microtubular axoneme.
Acesso aberto (Open Access)
Novel Microsatellite Markers for Brazilian Mangrove Oysters ( Crassostrea gasar ) and their Cross-Amplification in Crassostrea rhizophorae
(Universidade Federal do Pará, 2016-08) BALDEZ, Renata do Socorro Corrêa; MELO, Mauro Andre Damasceno de; SAMPAIO, Maria Iracilda da Cunha; TAGLIARO, Claudia Helena
A microsatellite CT/GT enriched genomic library was developed for Crassostrea gasar and twelve new polymorphic loci were isolated and characterized. The markers were successfully amplified from 25 individuals of Crassostrea gasar and 11 cross-amplified individuals of Crassostrea rhizophorae. There was no evidence of linkage between loci in either species.
Acesso aberto (Open Access)
Seasonal abundance of the shipworm Neoteredo reynei (Bivalvia, Teredinidae) in mangrove driftwood from a northern Brazilian beach
(2008-03) SANTOS FILHO, Carlos; TAGLIARO, Claudia Helena; BEASLEY, Colin Robert
Shipworms are important decomposers of wood, especially in mangrove forests where productivity is high. However, little emphasis has been given to the activity of shipworms in relation to the export of nutrients from mangroves to adjacent coastal areas. As a first step to obtaining such information, the frequency of colonized mangrove driftwood as well as shipworm density and length were studied by collecting washed up logs during a year at Ajuruteua beach, state of Pará, northern Brazil. A single species, Neoteredo reynei (Bartsch, 1920), was found colonizing driftwood. Although large colonized logs were most common on the beach, shipworm density was higher in small logs, especially during the dry season. In general, however, density was higher during the wet season (January to April) and lowest in July. Overall shipworm mean length was 9.66cm. In large logs, mean length increased between the wet and dry seasons. However, there was no difference in length among log size categories. Mean shipworm length was similar throughout most of the year but tended to be greater in July. Although salinity varied between 10.9 and 40 during the year, no relationship was found between salinity and density or length. The results suggest that shipworm activity in driftwood logs is relatively constant throughout the year. Increased air humidity and rainfall may promote survival during the wet season. Large logs may take longer to colonize and thus have lower densities than small ones which are scarce probably because they are destroyed rapidly by shipworm activity. However, data on the disintegration of logs would be necessary to test this hypothesis. Larger size of shipworms in the dry season may be related to growth after an earlier recruitment period. Shipworms in large logs during the dry season may be better protected from dessication and high temperatures by the insulating properties of the larger volume of wood.
Acesso aberto (Open Access)
Taxonomic implications of molecular studies on Northern Brazilian Teredinidae (Mollusca: Bivalvia) specimens
(2005-03) VALE, Sonia Maria Lima Santos do; TAGLIARO, Claudia Helena; BEASLEY, Colin Robert; SCHNEIDER, Horacio; SAMPAIO, Maria Iracilda da Cunha; SANTOS FILHO, Carlos; MÜLLER, Ana Cláudia de Paula
The current taxonomy of the Teredinidae (shipworms) is wholly based on morphology and up to now no molecular studies of the phylogeny of this group have been published. In the present study the relationships between four genera of the subfamilies Teredininae and Bankiinae were established and the efficiency of the 16S rRNA gene in characterizing four Teredinidae species was tested. Phylogenetic trees support the grouping of Bankia fimbriatula with Nausitora fusticula and of Neoteredo reynei with Psiloteredo healdi, but the genetic distances do not justify the classification of these species into two distinct subfamilies. The results show that B. fimbriatula, N. reynei and P. healdi specimens from the coast of the Brazilian state of Pará have five distinct 16S rRNA haplotypes, with one N. reynei haplotype differing from the other haplotypes in respect to at least seven sequences sites, indicating the existence of two very distinct sympatric lineages.
Acesso aberto (Open Access)
Ultraestrutura do espermatozóide de Protothaca pectorina (Lamarck) (Mollusca, Bivalvia) do litoral norte do Brasil
(1997-12) MATOS, Edilson Rodrigues; MATOS, Patrícia Santos; CASAL, Graça Maria Figueiredo; AZEVEDO, Carlos José Correia de
The ultrastructure of spermatozoa of the Protothaca pectorina (Lamarck, 1818) is described. The most significam differences were found in the structure and arreangement of the acrosomes, with contains two types of material, one fibrilar, the other electrondense granular. It is concluded that sperm ultrastructure is of the primitive type.