scholarly journals Reproductive strategy of a non-annual rivulid in a perennial wetland

2015 ◽  
Vol 105 (3) ◽  
pp. 288-296
Author(s):  
Laísa W. Cavalheiro ◽  
Clarice B. Fialho
Keyword(s):  
Sex Ratio ◽  
Reproductive Strategy ◽  
Aquatic Vegetation ◽  
Abiotic Factors ◽  
Gonadosomatic Index ◽  
Rio Grande ◽  
Reproductive Period ◽  
Rio Grande Do Sul ◽  
Reproductive Tactics ◽  
Patos Lagoon

ABSTRACT Atlantirivulus riograndensis (Costa & Lanés, 2009) is a fish registered to the basin of Patos lagoon and the adjacent coastal plains in southern states of Rio Grande do Sul and Santa Catarina, Brazil, found in shallow water courses with that have large quantities of aquatic vegetation and forest edges. The objective of this study was to investigate the reproductive strategy and tactics of this species including the sex ratio, the length at first maturity, spawning type, fecundity and the possible associations among reproduction and abiotic factors. Sampling of specimens occurred in perennial wetlands within the Banhado dos Pachecos wildlife refuge, in the city of Viamão, state of Rio Grande do Sul, Brazil, which is a conservation unit that belongs to an area of environmental protection in the Pampa Biome. The capture of 30 A. riograndensis specimens per month occurred from January to December of 2012. A total of 188 females and 172 males were captured and the total sex ratio was 1:1 in the sampled population. Sexual maturity of the species occurs after 13.59 and 11.92 mm (SL) for females and males, respectively. Both a multiple spawning and a long reproductive period (since August to March) were confirmed by the presence of post-ovulatory follicles that were observed through histological analysis and the values of the gonadosomatic index in females considered spawning capable. The average absolute fecundity of the species is of 19.33 (± 6.18) vitellogenic oocytes in mature ovaries. No significant relationship was found between mean GSI and the abiotic data. Reproductive tactics presented by A. riograndensis indicate a species with an opportunistic reproductive strategy, following the pattern of other species of the Rivulidae family.

Reproductive cycle of native viviparous fish species (Actinopterygii: Cyprinodontiformes: Goodeidae) in a subtropical Mexican lake

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Arely Ramírez-García ◽  
Rodrigo Moncayo-Estrada ◽  
Juan José González-Cárdenas ◽  
Omar Domínguez-Domínguez
Keyword(s):  
Sex Ratio ◽  
Reproductive Cycle ◽  
Fish Species ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
High Fertility ◽  
Reproductive Tactics ◽  
Subtropical Lake ◽  
Viviparous Fish ◽  
First Maturity

Abstract Reproductive tactics and strategies contribute to the persistence and maintenance of long-term populations in fish species. Members of the subfamily Goodeinae are a group of small-bodied freshwater fish with specialized reproduction (viviparity-matrotrophy). They are found in the highlands of central Mexico, most of them endemic. The aim of this study was to conduct a comprehensive investigation to evaluate the annual reproductive cycle of seven species of goodeines (splitfins). We carried out our study in the subtropical Lake Zacapu, Mexico, with bi-monthly sampling from May 2019 to March 2020. We obtain the fertility, size at first maturity (L50), sex ratio, and gonadosomatic index. Our result shows that populations of goodeines have high fertility compared to other populations of the same species in other aquatic systems and also to other species of goodein. We found that males mature at smaller sizes than females, the observed proportion of females was greater than males in all the goodeines. Lake Zacapu goodeines have two reproductive peaks, one in spring (April to June) and another in fall (September to November). These tactics (fertility rates, sex ratio, reproductive period) and strategies (viviparity-matrotrophy) favor reproductive success in this environmentally stable subtropical lake in the highlands of Mexico.

scholarly journals Non-seasonal reproduction in inseminating species of Mimagoniates (Characidae, Characiformes) from southern Brazil

2018 ◽  
Vol 58 ◽  
pp. 2
Author(s):  
Vinicius Renner Lampert ◽  
Marco Aurélio Azevedo
Keyword(s):  
Gonadosomatic Index ◽  
Rio Grande ◽  
Reproductive Period ◽  
Day Length ◽  
Size Analysis ◽  
Seasonal Reproduction ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Oocyte Size ◽  
Stomach Weight

Some aspects of reproduction in two species of Mimagoniates, M. microlepis (Steindachner 1877) and M. rheocharis Menezes & Weitzman 1990 are herein described. Samples were taken monthly from January 1998 to February 1999 in two streams in the locality of Maquiné, Rio Grande do Sul, Brazil. Results from the analysis of hundreds of specimens of M. microlepis and M. rheocharis in two investigated sites indicated mature specimens and peaks of the gonadosomatic index (GSI) along the year. There was a negative and significant correlation between M. microlepis male’s GSI and water temperature. Females of the latter species and both sexes of M. rheocharis, in turn, showed no correlation with any of the tested parameters (relative stomach weight, day length, rainfall). Absolute and relative fecundity are lower than in externally fertilized species of Characidae. Maximum oocyte length was 1.14 mm for M. microlepis and 1.02 mm for M. rheocharis and both species were characterized as total spawners based on the type of oocyte development estimated through oocyte size analysis. Features like non-seasonal reproductive period, low fecundity, and insemination may indicate adaptive advantages, which may enhance the chance of survival even with low energetic investment and improved fertilization.

scholarly journals Reproductive period and fecundity of Serrapinnus piaba (Characidae: Cheirodontinae) from the rio Ceará Mirim, Rio Grande do Norte, Brazil

2003 ◽  
Vol 1 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Jacira Silvano ◽  
Cristina L. C. Oliveira ◽  
Clarice B. Fialho ◽  
Hélio C. B. Gurgel
Keyword(s):  
Gonadosomatic Index ◽  
Rio Grande ◽  
Total Body Weight ◽  
Mature Female ◽  
Reproductive Period ◽  
Day Length ◽  
Maturation Stages ◽  
Total Body ◽  
Spearman Test ◽  
Test Correlation

Specimens of Serrapinnus piaba were collected monthly from April 2001 to April 2002 in the rio Ceará Mirim, Rio Grande do Norte State, Brazil. The reproductive period, determined through the monthly variation of the gonadosomatic index (GSI) and maturation stages, occurred from January to April. Non-parametric Spearman test was performed in order to test correlation of monthly GSI variation in males and females with water temperature, rainfall and day length. Rainfall and Temperature were correlated with GSI variation in females only and day length showed a negative correlation with GSI variation of males only. It was verified the presence of hooks on the anal fin of mature and maturing males along all the period of study. The absolute fecundity mean was 441 (±178.08) oocytes, determined by the number of yolky oocytes counted in 27 mature female gonads. The relative fecundity, estimated by the number of yolky oocytes divided by milligram of total body weight was 0.74 (± 0.19).

scholarly journals Diversity and spatial distribution of black flies (Diptera: Simuliidae) in the Ijuí river drainage basin, Rio Grande do Sul, Brazil

2019 ◽  
Vol 12 (2) ◽  
pp. 47-56
Author(s):  
Tieli Cláudia Menzel ◽  
Sirlei Maria Hentges ◽  
David Augusto Reynalte Tataje ◽  
Milton Norberto Strieder
Keyword(s):  
River Basin ◽  
Indicator Species ◽  
Drainage Basin ◽  
Abiotic Factors ◽  
Principal Component ◽  
Rio Grande ◽  
Anthropogenic Pressure ◽  
Black Flies ◽  
Rio Grande Do Sul ◽  
Significant Difference

Abstract. In southern Brazil there are several problems regarding the hematophageal activity of black flies, and the information on the distribution of species are still insufficient. In this study, our main goals were to recognize Simuliidae species and to analyze abiotic factors regarding the distribution of immature stages (larva and pupa) in streams from the Ijuí River basin, Northwest of Rio Grande do Sul, Brazil. We sampled simulids specimens in 27 study sites, covering three regions (high, intermediate and low altitude). Concomitantly, we recorded abiotic factors in the studied sites, such as: temperature, electrical conductivity, dissolved oxygen, atmospheric pressure, pH, altitude and stream width. For data analysis, we performed Kruskal-Wallis, ANOVA, Principal Component Analysis (PCA), Analysis of Indicator Species and Canonical Correspondence (CCA). A total of 10 species of black Flies was recorded. Simulium pertinax Kollar, Simulium incrustatum Lutz and Simulium orbitale Lutz were the most frequent. There was no significant difference in richness and density of the species between the different regions studied, except for Simulium jujuyense Paterson & Shannon. The sampled environments were segregated according to the location within the basin, and only S. jujuyense was considered an indicator species of the upper region. These results can be explained by the homogeneous conditions of the Ijuí River basin, which have suffered anthropogenic pressure mainly due to agricultural activities, resulting in losses in local aquatic biodiversity. Also, it may indicate that the control must be conducted considering the basin as a whole, and not only as isolated stretches of the streams.Diversidade e distribuição espacial de borrachudos (Diptera: Simuliidae) na bacia hidrográfica do rio Ijuí, Rio Grande do Sul, BrasilResumo. No sul do Brasil existem problemas com atividade hematofágica de borrachudos e as informações referentes à distribuição das espécies ainda são insuficientes. O presente estudo visa reconhecer as espécies de Simuliidae e analisar fatores abióticos quanto a distribuição dos estágios imaturos (larva e pupa) em riachos da Bacia do Rio Ijuí, no Noroeste do Rio Grande do Sul, Brasil. Foram coletados simulídeos em 27 pontos de estudo, cobrindo três regiões da bacia (alta, intermediária e baixa altitude). Concomitantemente, foi feito o registro de fatores abióticos nos trechos estudados, tais como: temperatura, condutividade elétrica, oxigênio dissolvido, pressão atmosférica, pH, altitude e largura do riacho. Foram realizadas análises de Kruskal-Wallis ou ANOVA, Análise de Componentes Principais (PCA), Análise de Espécie Indicadora e de Correspondência Canônica (CCA). Foi registrado um total de 10 espécies de Simuliidae. Simulium pertinax Kollar, Simulium incrustatum Lutz e Simulium orbitale Lutz foram as mais frequentes. Não ocorreu diferença na riqueza e na densidade das espécies entre as diferentes regiões estudadas, exceto para Simulium jujuyense Paterson & Shannon. Os ambientes nos pontos de amostragem foram segregados de acordo com a sua localização na bacia, e apenas S. jujuyense foi considerada uma espécie indicadora da região alta. Tais resultados podem ser explicados pelas condições homogêneas da Bacia do Rio Ijuí, que vêm sofrendo pressão antropogênica principalmente devido às atividades agrícolas, resultando em perdas na biodiversidade aquática local. Também, indicam que o controle deve ser realizado considerando a bacia como um todo e não apenas em trechos isolados dos riachos.

Recognizing Different Lifeways and Subsistence Practices through Analysis of the Material Cultures of Mound Sites in Rio Grande do Sul, Brazil

2020 ◽  
Vol 31 (2) ◽  
pp. 308-324
Author(s):  
Anderson Marques Garcia
Keyword(s):  
Central Region ◽  
Rio Grande ◽  
Rio Grande Do Sul ◽  
Hunter Gatherers ◽  
Patos Lagoon ◽  
Projectile Points ◽  
Brazilian State ◽  
Subsistence Practices ◽  
Mound Sites

In the Brazilian state of Rio Grande do Sul, the term cerrito was traditionally used to designate archaeological phenomena that emerge in the form of mounds in different landscapes. Except for recent research developed in the southwestern region of the Patos Lagoon, few advances have occurred since the 1980s in the study of cerritos in Brazil. This article presents an analysis of the lithic industries of sites with mounds in the southwestern region of the Patos Lagoon and in the central region in the current territory of Rio Grande do Sul. The results, along with other data from the sites, suggest that coastal sites were occupied by sedentary fisher-hunter-gatherers, who also possibly domesticated certain plants. Lithic material was scarce there and was mainly produced from pebbles and quartz cobbles using the anvil technique. In contrast, central region formations presented mounds on outcrops, using land, pebbles, and boulders; the area was occupied by a hunter-gatherer group that had projectile points and other instruments carved mainly by façonnage and débitage.

scholarly journals Population biology of shrimp Macrobrachium jelskii (Miers, 1778) (Decapoda, Palaemonoidea) at the Grande River at northwest of the state of Minas Gerais, Brazil

2012 ◽  
Vol 24 (3) ◽  
pp. 266-275 ◽  
Author(s):  
Samara de Paiva Barros-Alves ◽  
Ariádine Cristine Almeida ◽  
Vivian Fransozo ◽  
Douglas Fernandes Rodrigues Alves ◽  
José Carlos da Silva ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Frequency Distribution ◽  
Population Biology ◽  
Abiotic Factors ◽  
Mesh Size ◽  
Minas Gerais ◽  
Reproductive Period ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Monthly Basis

AIM: The population biology of the freshwater shrimp Macrobrachium jelskii was investigated here emphasizing the length-frequency distribution, sex ratio, reproductive period and juvenile recruitment. In addition, the abundance of individuals was correlated with the abiotic factors. METHODS: Samples were collected on a monthly basis from July 2005 to June 2007 along the river margin in shallow water of Grande River, at Planura region, State of Minas Gerais, Brazil (20º 09' S and 48º 40' W), using a trawl net (1.0 mm mesh size, and 2.0 m × 0.5 m wide). The fishing gear was handled by two people along the marginal vegetation of the Grande River in a course of 100 m, covered for one hour. In the laboratory, the specimens were identified, measured and sexed. RESULTS: A total of 2,789 specimens was analyzed, which corresponded to 1,126 males (549 juveniles and 577 adults) and 1,663 females (1,093 juveniles, 423 adults non-ovigerous and 147 ovigerous). The sex ratio differed significantly in favor of the females of M. jelskii (1:1.48; χ² = 103.95; p < 0.0001). The mean size of carapace length (CL) of females (6.32 ± 1.84 mm CL) was statistically higher than of males (5.50 ± 1.07 mm CL) (p < 0.001). The length-frequency distribution of the specimens revealed an unimodal pattern and non-normal distribution for males and females (W = 0.945; p < 0.01). No significant relationship between the abundance of M. jelskii and the environmental variables was observed (p = 0.799). CONCLUSION: The presence of ovigerous females and juveniles in the population suggests a continuous reproduction pattern and recruitment for M. jelskii at Planura region.

scholarly journals OCORRÊNCIA E DISTRIBUIÇÃO DE VERTEBRADOS AMEAÇADOS DE EXTINÇÃO NO PONTAL DA BARRA, PELOTAS, RIO GRANDE DO SUL, BRASIL / OCCURRENCE AND DISTRIBUTION OF THREATENED VERTEBRATE SPECIES AT PONTAL DA BARRA, PELOTAS, RIO GRANDE DO SUL, BRAZIL

2018 ◽  
Vol 3 (3) ◽  
pp. 301
Author(s):  
Giovanni Nachtigall Maurício ◽  
Omar Machado Entiauspe-Neto ◽  
Fernando Marques Quintela ◽  
Daniel Loebmann ◽  
Leonardo Amaral De Moraes
Keyword(s):  
Rio Grande ◽  
Iucn Red List ◽  
Vertebrate Species ◽  
Rio Grande Do Sul ◽  
Mammal Species ◽  
Patos Lagoon ◽  
Scenic Beauty ◽  
Wetland Site ◽  
Threatened Taxa ◽  
Environmental Integrity

O Pontal da Barra é uma área úmida localizada na praia do Laranjal, município de Pelotas, Rio Grande do Sul, no setor sul da laguna dos Patos. A área é rica em biodiversidade, abrigando várias espécies endêmicas dos biomas Mata Atlântica e Pampa, bem como espécies ameaçadas de extinção. Neste estudo reportamos dados detalhados sobre a ocorrência e distribuição, no Pontal da Barra, de oito espécies de vertebrados ameaçados: três peixes, Austrolebias nigrofasciatus Costa & Cheffe, Austrolebias wolterstorffi (Ahl) e Gymnotus refúgio Giora & Malabarba; uma espécie microendêmica e recém-descrita de réptil, Ophiodes enso Entiauspe-Neto et al.; três aves, Circus cinereus Vieillot, Calidris subruficollis (Vieillot) e Xolmis dominicanus (Vieillot); e uma espécie de mamífero, Leopardus geoffroyi (d’Orbigny & Gervais). Essas espécies são ameaçadas em nível nacional ou estadual. Entretanto, duas espécies microendêmicas restritas ao Pontal da Barra e arredores, Austrolebias nigrofasciatus e Ophiodes enso, também se enquadram como ameaçadas globalmente de acordo com os critérios da IUCN (União Internacional para a Conservação da Natureza), embora ainda não tenham sido avaliadas por essa organização. Destacamos que a área abriga as maiores populações conhecidas dessas espécies, o que qualifica o Pontal da Barra como uma prioridade global de conservação. Esse fato, juntamente com a beleza cênica e a integridade ambiental local, justifica a criação de uma unidade de conservação na área.Abstract:Pontal da Barra is a wetland site located at Laranjal beach town, municipality of Pelotas, Rio Grande do Sul state, in the southern end of Patos lagoon. The area is rich in biodiversity, harboring several species endemic to Atlantic Forest and Pampa biomes, as well as threatened taxa. In this paper we report detailed data on the occurrence and distribution of eight threatened vertebrate species at Pontal da Barra: three fishes, namely Austrolebias nigrofasciatus Costa & Cheffe, Austrolebias wolterstorffi (Ahl) and Gymnotus refugio Giora & Malabarba; a recently described microendemic species of reptile, Ophiodes enso Entiauspe-Neto et al.; three birds, namely Circus cinereus Vieillot, Calidris subruficollis (Vieillot) and Xolmis dominicanus (Vieillot); and a mammal species, namely Leopardus geoffroyi (d’Orbigny & Gervais). These species are threatened at national or state levels. However, two microendemic species restricted to Pontal da Barra and vicinity, namely Austrolebias nigrofasciatus and Ophiodes enso, also qualify as threatened at global level according to IUCN criteria, though both taxa have not been (yet) evaluated by IUCN Red List specialists. We highlight that the area harbor the largest known populations of these two species, thus qualifying as a global conservation priority. This fact, in conjunction with scenic beauty and environmental integrity, justify the creation of a conservation unit in the area.Key-words: Pontal da Barra, biodiversity; conservation; marshes; threatened species

scholarly journals Distribution and abundance of the Lesser electric ray Narcine brasiliensis (Olfers, 1831) (Elasmobranchii: Narcinidae) in southern Brazil in relation to environmental factors

2009 ◽  
Vol 57 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Gabriel Maciel de Souza Vianna ◽  
Carolus Maria Vooren
Keyword(s):  
Coastal Water ◽  
Latitudinal Gradient ◽  
Seasonal Pattern ◽  
Rio Grande ◽  
Bottom Trawl ◽  
Trawl Survey ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Patos Lagoon ◽  
Tropical Water

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.

scholarly journals Reproductive biology of Menticirrhus littoralis in southern Brazil (Actinopterygii: Perciformes: Sciaenidae)

2004 ◽  
Vol 2 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Aloisio Sirangelo Braun ◽  
Nelson Ferreira Fontoura
Keyword(s):  
Reproductive Biology ◽  
Seasonal Pattern ◽  
Gonadosomatic Index ◽  
Rio Grande ◽  
Minimum Size ◽  
Northern Coast ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Commercial Fish ◽  
Total Length

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.

scholarly journals Herpetofauna do Parque Natural Municipal de Sertão, Rio Grande do Sul, Brasil

2013 ◽  
Vol 13 (4) ◽  
pp. 290-298 ◽  
Author(s):  
Noeli Zanella ◽  
Almir de Paula ◽  
Samara Arsego Guaragni ◽  
Leonardo de Souza Machado
Keyword(s):  
Species Richness ◽  
Abiotic Factors ◽  
Rio Grande ◽  
Atlantic Rain Forest ◽  
Rio Grande Do Sul ◽  
Environmental Distribution ◽  
Average Temperature ◽  
Forested Areas ◽  
Maximum Temperatures ◽  
Original Vegetation

The northern part of the state of Rio Grande do Sul was extensively deforested in recent decades, and only isolated fragments of the original vegetation remain. The Parque Natural Municipal de Sertão comprises a remnant of Atlantic Rain Forest, one of the largest fragments in northern Rio Grande do Sul. This study examined the diversity of the herpetofauna, focusing on environmental distribution, seasonality and species richness. We used complementary methods of sampling such as pitfall traps, active search and occasional encounters. We recorded 23 species of frogs, nine snakes and one lizard. With respect to the relationship between amphibians and reptiles and the structural and abiotic factors of the environment, the edge of the fragment showed higher richness and increased dominance of amphibians and reptiles than the interior. The highest amphibian abundances were found when the minimum temperatures were higher and maximum temperatures were lower. The abundance of snakes was correlated with humidity, and species richness was influenced by humidity and monthly average temperature. Our results reinforce the importance of the conservation of forested areas to the maintenance of the species

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