oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
The metazoan parasites of Stellifer minor (Tschudi, 1844): an ecological approach
Oliva, Marcelo E.;Luque, Jose L.;Iannacone, Jose A.;
Memórias do Instituto Oswaldo Cruz , 1990, DOI: 10.1590/S0074-02761990000300003
Abstract: a quantitative and qualitative analysis of the parasite fauna of the sciaenid stellifer minor (tschudi) from chorrillos, peru, was made. some characteristics of the infectious processes, in terms of intensity and prevalence of infection, as a function of host sex and size, are given. moreover, comments on the characteristics of the parasite fauna, related with host role in the marine food webs are included. the parasite fauna of stellifer minor taken of chorrillos, peru, include the monogeneans pedocotyle annakohni, pedocotyle bravoi, rhamnocercus sp. and cynoscionicola sp., the digenean helicometra fasciata, the adult acantocephalan rhadinorhynchus sp. and the larval corynosoma sp., the nematode procamallanus sp., the copepods caligus quadratus, clavellotis dilatata and bomolochus peruensis and one unidentified isopod of the family cymothoidae. a distinctive characteristic of the parasite fauna (metazoa) of s. minor is the almost absence of larval forms.
Kudoa sciaenae (Myxozoa: Multivalvulidae) cysts distribution in the somatic muscles of Stellifer minor (Tschudi, 1844) (Pisces: Sciaenidae)
Oliva, Marcelo;Luque, Jose Luis;Teran, Luz;Llican, Leonardo;
Memórias do Instituto Oswaldo Cruz , 1992, DOI: 10.1590/S0074-02761992000100006
Abstract: the distribution of kudoa sciaenae cysts (myxozoa), in terms of intensity and prevalence, in the somatic muscles of the sciaenid stellifer minor, shows an apparent preference for the anterior body region, including the head. the observed preference seems to be a consequence of the differential distribution of muscle mass, in the defined area, because when density (cyst/g dry muscle), is considered, all the somatic areas, but not cephalic area, do no show significant differences in terms of mean intensity and prevalence.
Variación entre a os de la fauna de parásitos metazoos de Sciaena deliciosa (Tschudi, 1846) (Perciformes: Sciaenidae) en Lima, Perú Between-year variation of metazoan parasite fauna on Sciaena deliciosa (Tschudi, 1846) (Perciformes: Sciaenidae) in Lima, Peru  [cached]
José Iannacone,Luis Morón,Sandra Guizado
Latin american journal of aquatic research , 2010,
Abstract: Se evalúa la estructura comunitaria de los parásitos de Sciaena deliciosa (Tschudi, 1846), y se analiza si la composición, riqueza, diversidad, prevalencia e intensidad media de sus comunidades parasitarias cambia entre muestras tomadas con 20 a os de diferencia en Lima, Perú, entre agosto 1987 y julio 1988 y de agosto a septiembre del 2008 en peces de similar longitud corporal. Los parásitos metazoos fueron colectados y censados empleando las técnicas convencionales. La abundancia total fue de 1,7 (0 a 13) y la riqueza de especies de parásitos fue 0,7 (0 a 2 especies de parásitos por pez). Treinta hospederos mostraron infección con al menos un parásito (60%). Se encontraron siete taxa de parásitos: dos monogeneos Cynoscionicola sciaenae y Hargicotyle sciaenae; un digeneo Helicometra fasciata; un nemátodo Dycheline amaruincai, un acantocéfalo Tegorhynchus sp., y dos copépodos Caligus callaoensis y Lernanthropus huamani. Un análisis comparativo entre los parásitos de S. deliciosa entre 1987-1988 y 2008, muestran una disminución en la prevalencia de Tegorhynchus sp., D. amaruincai, Bomolochusperuensis y Neobrachiella oralis. La intensidad media aumentó para C. americana y Tegorhynchus sp. y disminuyó para C. callaoensis. Las diferencias entre a os pudieran estar influenciadas por las variaciones en la temperatura del agua que afectaron los estados larvales y/o reproducción de los copépodos, en la amplitud del periodo de estudio y en el tama o de la muestra. The community structure of parasites on Sciaena deliciosa (Tschudi, 1846), is evaluated and eventual changes are analyzed in the composition, richness, diversity, prevalence and mean intensity of parasite communities on fish specimens that were similar in body length but were sampled 20 years apart (August 1987 to July 1988 vs. August to September 2008) in Lima, Perú. Metazoan parasites were collected and counted employing conventional techniques. Total abundance was 1.7 (0-13) and parasite species richness was 0.7 (0-2 parasite species per fish). Thirsty hosts (60%) were infected by at least with one parasite. Seven parasite taxa were found: two monogeneans (Cynoscionicola sciaenae, Hargicotyle sciaenae), a digenean (Helicometra fasciata), a nematode (Dycheline amaruincai), an acanthocephalan (Tegorhynchus sp.), and two copepods (Caligus callaoensis, Lernanthropus huamani). This comparative analysis (parasites of S. deliciosa in 1987-1988 vs in 2008), showed a decreased prevalence of Tegorhynchus sp., D. amaruincai, Bomolochus peruensis, and Neobrachiella oralis. The mean intensity increased for C ame
Variación entre a?os de la fauna de parásitos metazoos de Sciaena deliciosa (Tschudi, 1846) (Perciformes: Sciaenidae) en Lima, Perú
Iannacone,José; Morón,Luis; Guizado,Sandra;
Latin american journal of aquatic research , 2010,
Abstract: the community structure of parasites on sciaena deliciosa (tschudi, 1846), is evaluated and eventual changes are analyzed in the composition, richness, diversity, prevalence and mean intensity of parasite communities on fish specimens that were similar in body length but were sampled 20 years apart (august 1987 to july 1988 vs. august to september 2008) in lima, perú. metazoan parasites were collected and counted employing conventional techniques. total abundance was 1.7 (0-13) and parasite species richness was 0.7 (0-2 parasite species per fish). thirsty hosts (60%) were infected by at least with one parasite. seven parasite taxa were found: two monogeneans (cynoscionicola sciaenae, hargicotyle sciaenae), a digenean (helicometra fasciata), a nematode (dycheline amaruincai), an acanthocephalan (tegorhynchus sp.), and two copepods (caligus callaoensis, lernanthropus huamani). this comparative analysis (parasites of s. deliciosa in 1987-1988 vs in 2008), showed a decreased prevalence of tegorhynchus sp., d. amaruincai, bomolochus peruensis, and neobrachiella oralis. the mean intensity increased for c americana and tegorhynchus sp. and diminished for c callaoensis. differences between years could be influenced by variations of sea temperature that affect larval stages and/or copepod reproduction over the course of the study period and size of the sample.
Chromosomes of Girella laevifrons (Tschudi 1846) (Osteichthyes: Kyphosidae)
Northland-Leppe,Irma; Véjar,Drina; Jara-Seguel,Pedro; Fuentes,Nelson; Nú?ez,Cristian;
Gayana (Concepción) , 2010, DOI: 10.4067/S0717-65382010000200007
Abstract: the chromosome number and karyotype morphology of girella laevifrons (tschudi 1846) are described for the first time. g. laevifrons presents a chromosome number of 2n = 48 and its karyotype is formed in both sexes by 24 acrocentric chromosome pairs, similar to what has been described for other species of girella gray, 1835.
Chromosomes of Girella laevifrons (Tschudi 1846) (Osteichthyes: Kyphosidae) Cromosomas de Girella laevifrons (Tschudi 1846) (Osteichthyes: Kyphosidae)  [cached]
Irma Northland-Leppe,Drina Véjar,Pedro Jara-Seguel,Nelson Fuentes
Gayana (Concepción) , 2010,
Abstract: The chromosome number and karyotype morphology of Girella laevifrons (Tschudi 1846) are described for the first time. G. laevifrons presents a chromosome number of 2n = 48 and its karyotype is formed in both sexes by 24 acrocentric chromosome pairs, similar to what has been described for other species of Girella Gray, 1835. El número cromosómico y la morfología del cariotipo de Girella laevifrons (Tschudi 1846) son descritos por primera vez. G. laevifrons presenta un número cromosómico 2n = 48 y su cariotipo está constituido por 24 pares de cromosomas acrocéntricos en ambos sexos, similar a lo documentado previamente para otras especies del género Girella Gray, 1835.
Population biology of Stellifer rastrifer, S. brasiliensis and S. stellifer in Caraguatatuba Bay, northern coast of S o Paulo, Brazil  [cached]
Maíra Pombo,Marcia Regina Denadai,Alexander Turra
Brazilian Journal of Oceanography , 2012, DOI: 10.1590/s1679-87592012000300001
Abstract: Ecosystems may reflect environmental changes in many respects, from the debilitation of individuals to alterations in community composition. Equally, population parameters may provide reliable indications of environmental changes. Members of the sciaenid fish genus Stellifer are usually very abundant where they occur, often with two or more species living in sympatry. Here, the population dynamics of three Stellifer species from southeastern Brazil were assessed. Sampling was carried out in shallow marine areas of Caraguatatuba Bay, from August 2003 to October 2004. The species evaluated were Stellifer rastrifer (n=3183), S. brasiliensis (n=357) and S. stellifer (n=116). The area under greater continental influence tended to support more, but smaller individuals. Size variations over time were similar among species and negatively correlated with Krel, which showed smooth fluctuations. The general length-frequency distribution was concentrated between 6.0 and 9.0 cm, and the great majority of females did not present mature gonads during the sampling period. The findings support the existence of a stratification by size for these species, indicating that the area is essential for the development of younger fish. Failure to consider these characteristics for the management of similar areas may have serious implications for these environments. Os ecossistemas podem refletir mudan as ambientais em muitos aspectos, desde o enfraquecimento dos indivíduos até altera es na composi o da comunidade. Do mesmo modo, os parametros populacionais podem fornecer indica es confiáveis de mudan as ambientais. Sciaenídeos do gênero Stellifer s o peixes geralmente muito abundantes e em suas popula es é frequente a ocorrência de duas ou mais espécies simpátricas. No presente trabalho, a dinamica populacional de três espécies de Stellifer do sudeste do Brasil foi avaliada. A amostragem ocorreu em águas rasas das zonas marinhas da Baía de Caraguatatuba, de agosto de 2003 a outubro de 2004. As espécies avaliadas foram Stellifer rastrifer (n = 3.183), S. brasiliensis (n = 357) e S. stellifer (n = 116). Os resultados mostraram que a área sob maior influência continental tende a suportar um número maior de indivíduos menores. Varia es de tamanho ao longo do tempo foram semelhantes entre as espécies e negativamente correlacionadas com o Krel, que apresentou flutua es suaves. De modo geral a distribui o de freqüência de comprimento ficou concentrada entre 6,0 e 9,0 cm e para a grande maioria das fêmeas as g nadas se apresentaram imaturas durante o período avaliado. Os resultad
Aspectos biológicos de Stellifer stellifer (Bloch) na pesca artesanal do camar?o sete-barbas, Arma??o do Itapocoroy, Penha, Santa Catarina, Brasil
Almeida, Laura Ribas de;Branco, Joaquim Olinto;
Revista Brasileira de Zoologia , 2002, DOI: 10.1590/S0101-81752002000200016
Abstract: stellifer stellifer (bloch, 1790) is one among the most abundant ictiofauna species which are caught by sea-bob-shrimp's artisanal fishery in arma??o do itapocoroy. aiming to analyze its population structure, a total of 1459 specimens were collected from july/1996 to august/1997. stellifer stellifer presented lengths varying between 3,7 and 17,7 cm, macroscopic sex differentiation started from 6,0cm, with a higher frequency of females (sex ratio = 1:3,2). the relationship between length and weight was wt = 0,0073lt3,1415. first maturation size was determined for females (7,5 cm) and males (8,1 cm). the fishery acts in a similar way on juveniles and adults. stellifer stellifer presented two spawning seasons, one in spring and another in autumn.
Molecular Phylogeny of Weakfish Species of the Stellifer Group (Sciaenidae, Perciformes) of the Western South Atlantic Based on Mitochondrial and Nuclear Data  [PDF]
Andressa Jisely Barreto Barbosa, Iracilda Sampaio, Horacio Schneider, Simoni Santos
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0102250
Abstract: The phylogenetic relationships within the Stellifer group of weakfishes (Stellifer, Odontoscion, Ophioscion, and Bairdiella) were evaluated using 2723 base pairs comprising sequences of nuclear (rhodopsin, TMO-4C4, RAG-1) and mitochondrial (16S rRNA and COI) markers obtained from specimens of nine species. Our results indicate a close relationship between Bairdiella and Odontoscion, and also that the genus Stellifer is not monophyletic, but rather that it consists of two distinct lineages, one clade containing S. microps/S. naso/S. brasiliensis and the other, S. rastrifer/S. stellifer/Stellifer sp. B, which is closer to Ophioscion than the former clade. The O. punctatissimus populations from the northern and southern Brazilian coast were also highly divergent in both nuclear (0.8% for rhodopsin and 0.9% for RAG-1) and mitochondrial sequences (2.2% for 16S rRNA and 7.3% for COI), which we conclude is consistent with the presence of two distinct species. The morphological similarities of the members of the Stellifer group is reinforced by the molecular data from both the present study and previous analyses, which have questioned the taxonomic status of the Stellifer group. If, on the one hand, the group is in fact composed of four genera (Stellifer, Ophioscion, Odontoscion, and Bairdiella), one of the two Stellifer clades should be reclassified as a new genus. However, if the close relationship and the reduced genetic divergence found within the group is confirmed in a more extensive study, including representatives of additional taxa, this, together with the morphological evidence, would support downgrading the whole group to a single genus. Obviously, these contradictory findings reinforce the need for a more systematic taxonomic revision of the Stellifer group as a whole.
Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil
Chaves, Paulo de Tarso C.;Vendel, Ana Lúcia;
Brazilian Archives of Biology and Technology , 1998, DOI: 10.1590/S1516-89131998000400006
Abstract: feeding habits of stellifer rastrifer (perciformes, sciaenidae) at guaratuba mangrove, parana, brazil, were studied from february 1996 to february 1997. it was observed that its diet was based on invertebrates, mainly decapoda non-brachyura and polychaeta. in a smaller proportion there were plants, copepoda, gammaridea and mollusca. the level of contribution of each food item changed according to the season and the individual size. such plasticity in feeding behaviour was similar to that described to some fish populations from other estuaries, and could be an indicator of the high level of instability presented by this kind of ecosystem.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.