scholarly journals Distribution, abundance and morphometry of Atlantoraja cyclophora (Regan, 1903) (Elasmobranchii: Rajidae) in southern Brazil, Southwestern Atlantic

2004 ◽  
Vol 2 (3) ◽  
pp. 137-144 ◽  
Author(s):  
María Cristina Oddone ◽  
Carolus Maria Vooren

A total of 459 individuals of Atlantoraja cyclophora were captured along the Rio Grande do Sul coast between latitudes 30º40'S and 34º30'S. Two surveys were performed, in the winter 2001 and in the summer/autumn 2002, using bottom-trawl between the depths of 100 and 600 m. This species occurred between 100 and 300 m deep, without significant differences in the frequency of occurrence and abundance (CPUE; kg/hour) between latitudes, depth and seasons. The sex ratio was not significantly different from 1:1 in all depths. In the study area, temperature ranged between 10.0 ºC and 17.6 ºC and salinity between 35.2 e 36.0 ppm. There was no correlation between CPUE and depth, temperature and salinity. Mean total length of females (53.2 cm) was significantly larger than males (50.9 cm). No differences were detected in mean total length between seasons, but mean total length was significantly larger in depths of 100 m and 200 m. The distribution of the frequencies of total length was asymmetric, indicating rareness or lack of juveniles in the samples.

2009 ◽  
Vol 57 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Gabriel Maciel de Souza Vianna ◽  
Carolus Maria Vooren

The distribution and abundance of the lesser electric ray, Narcine brasiliensis, was assessed based on bottom-trawl survey data collected off the coast of Rio Grande do Sul, southern Brazil. Between 1980 and 1984 and in 2005, 416 bottom trawl hauls were carried out at depths of 10-100 m. Narcine brasiliensis occurred mainly in waters with bottom temperature between 20 and 25ºC. Density of the species was higher between the depths of 10 and 20 m, during the summer and autumn. The seasonal pattern of N. brasiliensis in the shallow coastal water of Rio Grande do Sul reflects a southward migration in summer. This is conditioned by the southward advance of warmer and high-salinity Tropical Water of the Brazil Current In winter, the return or northward migration is a response to seasonal cooling of the coastal waters and to the northward advance of cold Coastal Water of lower salinity. The latitudinal gradient in density of N. brasiliensis was related to the latitudinal gradient in salinity of the bottom waters. This was caused by the freshwater runoff from the Patos Lagoon establishing a physical barrier to the occurrence of the species farther south than the city of Rio Grande.


2004 ◽  
Vol 2 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Aloisio Sirangelo Braun ◽  
Nelson Ferreira Fontoura

Menticirrhus littoralis is an important sport and commercial fish species in southern Brazil. This paper aims to analyze the reproductive biology of the species in Rio Grande do Sul coastal waters. Captures were carried out at Cidreira's fishing pier (30º 08' S; 50º 11' W) located on the Northern Coast of Rio Grande do Sul, where sport-fishing takes place throughout the year. Sport fishermen using hook-and-line with different hook sizes and varied baits exclusively made the captures. A total of 807 individuals were obtained from June 1997 to May 1998. Sexual proportion was 0.67 female for each male (323 females and 484 males; chi2c = 32.120; DF=1; P<0.001). The smallest individual (total length) for captured animals was a male of 13 cm whereas the largest was a female of 46 cm. The minimum size (total length) for a mature female was 19.8 cm. The size at first maturation (L50) was 23 cm and females larger than 27 cm spawned at least once (L100). The reproductive period for M. littoralis is from September to March. Gonadosomatic index (GSI) showed a clear seasonal pattern. Mean ovarian weight was highest in November when it reached 5% of total body weight. Apparently, there is a size gradient for M. littoralis in the area. Larger individuals inhabit deeper water, and they move to the coast mainly for spawning.


2003 ◽  
Vol 1 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Ana Paula S. Dufech ◽  
Marco A. Azevedo ◽  
Clarice B. Fialho

The diet of two populations of Mimagoniates rheocharis, from two freshwater streams of the rio Tramandaí, northeastern Rio Grande do Sul, Brazil, are described and compared. The specimens were collected monthly from January 1998 to March 1999, with dip nets and seine nets and preserved in 10% formalin. In laboratory, the standard length of each specimen was measured. The stomachs were removed and dissected for identification of the alimentary items. The data were analyzed using the frequency of occurrence, percent composition and index of alimentary importance methods, being the last two compared among different classes of standard length. Three methods of analysis showed the highest values for allochthonous insects, regardless the locality of collection or body size of the specimens.


Zootaxa ◽  
2006 ◽  
Vol 1177 (1) ◽  
pp. 21 ◽  
Author(s):  
M. E. ANDERSON ◽  
MICHAEL M. MINCARONE

A new species of deep-sea eelpout, Pachycara alepidotum, is described from four specimens, 199– 282 mm SL, collected in the upper bathyal zone off Rio Grande do Sul state, southern Brazil, and is the first record of the genus in the southwestern Atlantic. It is characterized by its lack of scales and ventral lateral line, few caudal vertebrae and only 1–2 rakers on the upper limb of the first gill arch. The largest specimen is an adult female.


2019 ◽  
Vol 2 ◽  
pp. 28
Author(s):  
Marcelo Pereira de Barros ◽  
Ana Paula Lima da Silveira ◽  
Bruna Reis Ferreira

As aves destacam-se dentro dos vertebrados por serem um grupo diverso e adaptado a diferentes ambientes, a composição da comunidade de aves de um determinado local é um importante bioindicador ambiental, pois ela reflete alterações recentes ou pretéritas de determinada área. Na Bacia Hidrográfica do Rio dos Sinos, as pressões sobre os remanescentes de ecossistemas naturais são intensas em decorrência da urbanização crescente, do estabelecimento de indústrias e da ampliação das fronteiras agrícolas, esses fatores associados geram a redução e fragmentação de habitats, com impactos irrecuperáveis para a flora e a fauna. Devido à escassez de dados sobre a avifauna do município de Taquara, o presente estudo teve como objetivo levantar informações sobre o grupo, listando as espécies de aves locais. Entre agosto de 2016 e junho de 2017 foram realizadas quatro amostragens mensais em duas áreas rurais do município, totalizando 44 campanhas de observação e 132 horas de esforço amostral. As espécies foram identificadas e classificadas conforme sua frequência de ocorrência mensal, em espécies comuns e raras. Foram registradas 133 espécies distribuídas em 47 famílias, o que representa mais de 20% das espécies ocorrentes para o estado. Ao longo do período amostrado, 90 espécies foram classificadas como comuns e 47 consideradas raras para as áreas pesquisadas.Palavras-chave: Aves. Bacia hidrográfica do Rio dos Sinos. Preservação.ABSTRACTBirds stand out within vertebrates because they are a diverse group adapted to different environments. The composition of the bird community of a certain place is an important environmental bioindicator since it reflects recent or previous environmental disturbances of a certain area. In the Sinos River Basin, environmental pressures on the remnants of natural ecosystems are intense as a result of increasing urbanization, the establishment of industries and expansion of agricultural frontiers which generate habitat reduction and fragmentation with irrecoverable damages on flora and fauna. Due to the scarcity of data on the avifauna of the municipality of Taquara, the present study aimed to gather information and list the species of local birds. Between August 2016 and June 2017, four monthly samplings were carried out in two rural areas of the municipality, totaling 44 observation campaigns and 132 hours of sample effort. The species were identified and classified as common and rare according to their frequency of occurrence. There were 133 species distributed in 47 families, representing more than 20% of the species that occurred in the state. During the sampled period, 90 species were classified as common and 47 were considered rare for the areas surveyed.Keywords: Birds. Hydrographic basin of Sinos River. Preservation.


2019 ◽  
Vol 36 (2) ◽  
pp. 55-60 ◽  
Author(s):  
Vanessa da Silva Fay ◽  
Tatiana Schäffer Gregianini ◽  
Ana Beatriz Gorini da Veiga ◽  
Stela Maris Bottin Gonçalves ◽  
Diana Mara Rodrigues ◽  
...  

Author(s):  
Gratchela D. Rodrigues ◽  
Eduardo Blodorn ◽  
Ândrio Zafalon-Silva ◽  
William Domingues ◽  
Roberta Marques ◽  
...  

Author(s):  
Daniel Danilewicz ◽  
Eduardo R. Secchi ◽  
Paulo H. Ott ◽  
Ignacio B. Moreno ◽  
Manuela Bassoi ◽  
...  

The patterns of habitat use by the franciscana dolphins (Pontoporia blainvillei) along its distribution are poorly known. This study investigates the patterns of habitat use with respect to depth for 181 individuals of different age, size, gender and reproductive condition off Rio Grande do Sul, southern Brazil. The results reveal that franciscanas are very homogeneously distributed according to depth. Individuals from all lengths utilize nearly the entire range of depths of the surveyed area. Larger or older animals do not use deeper waters than younger animals, indicating that body size and age are not limiting factors for franciscanas that occupy deeper or offshore waters. Gestation seems to not cause a change in the distribution of females. Although the sex-ratio of the overall data did not vary from 1:1 in different depth intervals, a small-scale comparison between the northern and southern coast demonstrated the existence of some kind of sexual segregation. Franciscana by-catch in Rio Grande do Sul is not sustainable and it is agreed that management procedures are needed. Nevertheless, the available data on species distribution do not allow the designing of a protected area in order to minimize the by-catches of a particular sex/reproductive class.


Check List ◽  
2016 ◽  
Vol 12 (5) ◽  
pp. 1964
Author(s):  
Omar Machado Entiauspe-Neto ◽  
Tângela Denise Perleberg ◽  
Marco Antonio de Freitas

Faunistic inventories regarding natural history of amphibians and reptiles are considered scarce and very little is known about their assemblages in urban areas; the Pampas morphoclimatic domain, also known as Uruguayan Savannah or Southern Grasslands, is also poorly known regarding their faunal composition.  Herein, we present a checklist of 16 amphibian and 20 reptile species recorded over a course of four years in the Instituto Federal de Educação, Ciências e Tecnologia, Câmpus Pelotas-Visconde da Graça, in Pelotas, Rio Grande do Sul, Brazil. We also present data on natural history and discuss conservation efforts to be undertaken in the area, in one of the least preserved and known Brazilian morphoclimatic domains, providing insights into urban herpetofaunal diversity patterns and showing the importance of modified areas in its conservation.


2014 ◽  
Vol 74 (3) ◽  
pp. 656-658 ◽  
Author(s):  
VS Sturza ◽  
STB Dequech ◽  
M Toebe ◽  
TR Silveira ◽  
A Cargnelutti Filho ◽  
...  

Microtheca spp. (Coleoptera: Chrysomelidae) are insect pests primarily related to Brassicaceae crops. In the State of Rio Grande do Sul (RS), southern Brazil, they are found on forage turnip, Raphanus sativus L. var. oleiferus Metzg., which is commonly grown during fall/winter seasons. This work reports the predation of Microtheca spp. larvae by Toxomerus duplicatus Wiedemann, 1830 (Diptera: Syrphidae) larvae, on forage turnip crop, in Santa Maria, RS. This register provides new information about Microtheca spp. natural enemies in Brazil, which might be a new option for integrate pest management of these species.


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