scholarly journals Reproduction and feeding ecology of Amphisbaena munoai and Anops kingi (Amphisbaenia, Amphisbaenidae) in the Escudo Sul-Rio-Grandense, southern Brazil

2011 ◽  
Vol 101 (1-2) ◽  
pp. 93-102 ◽  
Author(s):  
Rafael L Balestrin ◽  
Lize H Cappellari
Keyword(s):  
Feeding Ecology ◽  
Original Data ◽  
Adult Males ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Gut Content ◽  
Insect Larvae ◽  
Males And Females ◽  
Sexually Mature ◽  
Unimodal Pattern

This study presents original data on the reproduction and feeding ecology of two syntopic amphisbaenians, Amphisbaena munoai Klappenbach, 1969 and Anops kingi Bell, 1833, from southern Brazil. Sampling was carried out from April 2004 to April 2006 at a highland area located in São Jerônimo and Barão do Triunfo municipalities, Rio Grande do Sul, Brazil. A total of 647 amphisbaenians were collected, 510 specimens of A. munoai and 137 specimens of A. kingi, of which 130 and 93, respectively, had their gonads and gut content analyzed. Both species presented a unimodal pattern of seasonal distribution, sexually mature females with significantly larger snout vent length (SVL) than sexually mature males, and seasonal reproductive cycle. Adults of A. kingi had significantly larger (SVL) than those of Amphisbaena munoai. Both species had generalist diets, but termites (Isoptera) was a staple item in their diet. Greater predominance of insect larvae was observed in the diet of A. kingi, which may be due to its larger body in comparison to A. munoai. Insect larvae ingested by A. kingi were significantly larger than those ingested by A. munoai. Diets of adult males and females of both species were not significantly different. The ontogenetic diet comparison in both species revealed significant numerical differences, with adults consuming higher numbers of prey.

scholarly journals Feeding ecology in the small neotropical amphisbaenid Amphisbaena munoai (Amphisbaenidae) in southern Brazil

2006 ◽  
Vol 96 (4) ◽  
pp. 487-489 ◽  
Author(s):  
Jorge S. Bernardo-Silva ◽  
Eduardo M. Von-Mühlen ◽  
Marcos Di-Bernardo ◽  
Jochen Ketterl
Keyword(s):  
Feeding Ecology ◽  
Alimentary Tract ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Gut Content ◽  
Insect Larvae ◽  
Invertebrate Prey ◽  
Prey Items ◽  
Individual Prey

We analyzed the alimentary tract of 66 specimens of Amphisbaena munoai Klappenbach, 1969 from the Serra do Sudeste, state of Rio Grande do Sul, southern Brazil. Forty specimens (60.6%) had prey items in their gut. The diet consisted mainly of small invertebrate prey, such as termites, insect larvae and ants. The most abundant prey item was termites, found in 62.5% of the non empty stomachs. The high number of individual prey items in the majority of stomachs, the small size of the regular prey items, and the absence of gut content in specimens of A. munoai kept alive for about two days, indicate that this species forages very frequently. The predominance of fossorial prey items and the occasional records of nomadic ants lead us to suggest that A. munoai usually feeds underground, and occasionally forages on the surface.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

Social behavior in a non-pupping colony of Steller sea lions (Eumetopias jubata)

1975 ◽  
Vol 53 (11) ◽  
pp. 1596-1613 ◽  
Author(s):  
A. S. Harestad ◽  
H. D. Fisher
Keyword(s):  
Relative Proportion ◽  
Behavior Patterns ◽  
Social Stability ◽  
Adult Males ◽  
Steller Sea Lions ◽  
Female Behavior ◽  
Sea Lions ◽  
Energy Conserving ◽  
Males And Females ◽  
Sexually Mature

An ethogram of 22 behavior patterns is described. Larger and older sea lions (Eumetopias jubata) are dominant to smaller and younger ones. Males are more socially involved, and their behavior becomes more complex than that of females.Adult male and female behavior is less vigorous than that of subadult males. Territories where adult males and females are concentrated are more tranquil than areas where subadult males aggregate. Since females avoid areas of activity and harassment by sexually mature subadult males, they group in territories which act as refuges. This contributes to the spacial organization of the colony.The behavior of subadult males results in social disruption, whereas social stability is accommodated by adult males and females who are more stationary and so maintain prolonged social relationships.Non-pupping colonies are spacially organized similar to pupping colonies except for the relative proportion of age–sex classes. Socially, non-pupping colonies are less organized than pupping colonies. Social organization in E. jubata is promoted by the tranquil or energy-conserving behavior and ability of adults and inhibited by the behavior of subadult males.

Population biology and growth of the hermit crab Dardanus insignis at Armação do Itapocoroy, southern Brazil

2002 ◽  
Vol 82 (4) ◽  
pp. 597-603 ◽  
Author(s):  
Joaquim Olinto Branco ◽  
Alexander Turra ◽  
Flávio Xavier Souto
Keyword(s):  
Population Biology ◽  
Outer Part ◽  
Growth Function ◽  
Hermit Crabs ◽  
Reproductive Pattern ◽  
Southern Brazil ◽  
Von Bertalanffy Growth Function ◽  
Temporal Oscillation ◽  
Males And Females ◽  
Unimodal Pattern

This study was conducted between January and December 1995 at Armação do Itapocoroy, Penha, Santa Catarina, southern Brazil. Monthly samples were carried out in the morning, afternoon, and evening using two over-trawls with 6 m at the opening, 3·0-cm mesh at the outer part and 2·0-cm mesh in the bag. Dardanus insignis was collected year round but with higher densities in September and October. The hermit crabs were more abundant during the evening than the afternoon but no differences were recorded between morning and both evening and afternoon. Females were slightly more abundant than males but the sex ratio did not differ from 1:1. Females were more abundant in the smallest size-classes (<1·8 cm) while males outnumbered females in the largest ones (>2·2 cm). The individuals of this population of D. insignis have a mean cephalothoracic length of 1·89±0·40 cm (range 1·00 to 3·90 cm) and a mean weight of 40·26±27·06 g. The size distribution showed an unimodal pattern, with males being larger than ovigerous females, which, in turn, were larger than non-ovigerous females. Dardanus insignis showed a seasonal reproductive pattern with a peak from September to November and complete absence of ovigerous females from April to August. The von Bertalanffy growth function (VBGF) with temporal oscillation fitted for this population of D. insignis had the following parameters: L∞=4·40 cm, K=0·60, C=0·95, WP=0·35. Recruitment was estimated to start in September and was extended to the following months. Estimates of longevity ranged from 20 to 62 months. A mortality rate of 2·21 was estimated based on the length converted catch curve. The cephalothoracic length of males and females showed, respectively, positive and negative allometry with both cephalothoracic width and crab weight.

Reproduction of the water snake Helicops infrataeniatus (Colubridae) in southern Brazil

2005 ◽  
Vol 26 (4) ◽  
pp. 527-533 ◽  
Author(s):  
Luís Felipe Schmidt de Aguiar ◽  
Marcos Di-Bernardo
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Statistical Difference ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Water Snake ◽  
Males And Females ◽  
Two Peaks

AbstractThe reproductive cycle, sexual maturity, fecundity, and sexual dimorphism of Helicops infrataeniatus Jan, 1865, were inferred from the analysis of 374 preserved specimens (110 males, 140 females) from the eastern Central Depression of Rio Grande do Sul, Brazil. There was no statistical difference between the SVL of newborn males and females, but mature females attained greater length than mature males. The tail of mature individuals was proportionally longer in males than in females. Males matured at a smaller size than females. The reproductive cycle of this species was longer than what is known for oviparous colubrids from subtropical and temperate zones of Brazil. In the studied population, vitellogenesis occurred from September to February. Oviductal embryos were found from September to May. Births took place in September, January, February and March, and occurred in two peaks. Litter size ranged from 5 to 22 offspring. The differences between the number of vitellogenic follicles and embryos, and between embryos and newborns were not significant, thus practically all follicles were generally converted into embryos and embryos into newborns.

scholarly journals Reproductive biology and sexual dimorphism in Cnemidophorus vacariensis (Sauria, Teiidae) in the grasslands of the Araucaria Plateau, southern Brazil

2009 ◽  
Vol 99 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Fabíola M. Rezende-Pinto ◽  
Laura Verrastro ◽  
Juliana C. Zanotelli ◽  
Paulo C. R. Barata
Keyword(s):  
Sexual Dimorphism ◽  
Environmental Factors ◽  
Clutch Size ◽  
Morphological Characteristics ◽  
Rio Grande ◽  
Reproductive Season ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Threatened Fauna ◽  
Sexually Mature

The reproductive cycle and sexual dimorphism of the lizard Cnemidophorus vacariensis Feltrim & Lema, 2000 were studied on the basis of data gathered between August 2004 and August 2006 in Vacaria, Rio Grande do Sul, Brazil. Snout-vent length (SVL) of sexually mature males varied between 48.8 and 72.9 mm (x = 63.3 ± 6.0 mm; n = 76) and, for females, between 57.4 and 81.8 mm (x = 70.0 ± 5.9 mm; n = 73). Other morphological characteristics were also compared between sexes. Reproduction was seasonal, and observations indicate two clutches in the same reproductive season. Clutch size and other reproductive characteristics were analyzed as well as the relation between reproduction and environmental factors. Cnemidophorus vacariensis is apparently endemic to highland plateaus in southern Brazil and has been classified as vulnerable on some lists of threatened fauna in this country. Some suggestions for conservation measures are presented, due to the observed degradation of this species' environment.

scholarly journals A note on strandings of Bryde's whales (Balaenoptera edeni) in the southwestern Atlantic

2020 ◽  
Vol 21 (1) ◽  
pp. 9-15
Author(s):  
Eduardo Cabral Casado Lima
Keyword(s):  
Sexual Maturity ◽  
Brazilian Coast ◽  
Southwestern Atlantic ◽  
Simple Linear Regression ◽  
Rio Grande Do Sul ◽  
Significant Difference ◽  
Males And Females ◽  
Anthropogenic Threats ◽  
Sexually Mature

The aim of the present study is to trace a diagnosis of Bryde´s whale (Balaenoptera edeni) strandings in jurisdictional Brazilian waters through the compilation of published records and those conveyed in communication channels. During 1972 and 2015, 74 strandings were documented between the states of Rio Grande do Sul and Rio de Janeiro, Bahia and Maranhão. The results point out statistically significant differences between the frequencies of strandings in relation to Brazilian regions (χ² = 103.17), with the highest abundance found for the Southeast region (71.62%). Statistically significant differences were also observed between stranding frequency and sexual maturity (χ² = 12.31), with a higher abundance for sexually mature females(54.25%). No statistically significant difference between the stranding frequency in relation to seasonality (χ² = 2.34) was observed. Regarding sex, no statistically significant difference between stranding frequency for males and females was found (χ²=3.12). A trend of increasing B.edeni strandings was observed from the 1980s onwards, by the use of a simple linear regression. This may be due to population growth of the species, increased monitoring throughout the Brazilian coast, and/or increased anthropogenic threats. Thus,stranding monitoring is important for the adoption of conservation measures for this species, as well as for the determination of regional stocks through genetic analyses.  

scholarly journals Diet of Teius oculatus (Sauria, Teiidae) in southern Brazil (Dom Feliciano, Rio Grande do Sul)

2007 ◽  
Vol 97 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Lize Helena Cappellari ◽  
Thales de Lema ◽  
Paulo Prates Jr. ◽  
Carlos Frederico Duarte da Rocha
Keyword(s):  
Diet Composition ◽  
Stomach Contents ◽  
Prey Type ◽  
Adult Males ◽  
Rio Grande Do Sul ◽  
Importance Value Index ◽  
Importance Value ◽  
Important Prey ◽  
Adult Females ◽  
Males And Females

We analyzed stomach contents of 58 specimens of Teius oculatus (D'Orbigny & Bibron, 1837) (20 adult males, 17 adult females and 21 juveniles) captured in Dom Feliciano, RS, Brazil, to evaluate diet composition and sexual and ontogenetic variations in prey consumption. Diet was composed of 15 prey categories, all arthropods. Orthoptera was the most frequent prey type. Quantitatively, termites were the most important prey item (59.5%). There were no significant differences between the diets of adult males and females. Ontogenetic differences were found, mainly concerning volume of prey consumed. Adult lizards ingested significantly larger prey than juveniles (U = 170.00; p < 0.001). Juveniles, although having a comparatively less diverse diet (10 prey types) consumed a larger number of items (45.7% of total). Diet similarity was higher between juveniles and adult males (Ojk = 0.97) and prey diversity was higher in the diet of adult females (H' = 2.65). Based on importance value index the most important item in the diet of T. oculatus was Orthoptera. We conclude that T. oculatus in Dom Feliciano has a relatively generalized diet and it is an opportunist lizard, feeding on arthropods, mainly insects.

scholarly journals Growth of the Silverside Atherinella brasiliensis in Tramandaí Estuary, Southern Brazil (Actinopterygii: Atherinopsidae)

2007 ◽  
Vol 5 (4) ◽  
pp. 485-490 ◽  
Author(s):  
Giovana Bervian ◽  
Nelson F. Fontoura
Keyword(s):  
Growth Parameters ◽  
Growth Curves ◽  
Von Bertalanffy ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Beach Seine ◽  
Frequency Distributions ◽  
First Reproduction ◽  
Males And Females ◽  
One Year

The growth of Atherinella brasiliensis (Quoy & Gaimard, 1824) was studied through monthly samples taken at Tramandaí Lagoon, Imbé County, Rio Grande do Sul, Brazil. Animals were captured using a beach seine net. Length-weight relationships and age- growth curves for males and females were adjusted. The growth parameters of the von Bertalanffy growth formulae are Linf=16.0 and k=0.883 for males and Linf=17.0 and k=0.825 for females. First reproduction occurred one year after recruitment. Once reaching maturity, adults of A. brasiliensis reproduced once more in the next spring with two-year-olds and disappeared soon after from size frequency distributions. A few captured animals showed a size compatible with an age of three years.

scholarly journals Taxonomic review of the Neotropical genus Neopachylus (Arachnida, Opiliones, Gonyleptidae)

2015 ◽  
Vol 105 (1) ◽  
pp. 101-121
Author(s):  
Vivian Moreira Montemor ◽  
Cibele Bragagnolo ◽  
Ricardo Pinto-da-Rocha
Keyword(s):  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Santa Catarina ◽  
Taxonomic Review ◽  
Males And Females ◽  
Subjective Synonym

A taxonomic review of the genus Neopachylus Roewer, 1913 together with keys to the species for both males and females are presented. Gephyropachylus marginatus Mello-Leitão, 1931 is considered a junior subjective synonym of Neopachylus serrinha Soares & Soares, 1947, and Huralvius incertus Mello-Leitão, 1935 is considered a synonym of Neopachylus nebulosus (Mello-Leitão, 1936). This genus is restricted to southern Brazil, occurring in states of Paraná, Santa Catarina and Rio Grande do Sul.

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