scholarly journals Reproductive biology and feeding of Curimatella lepidura (Eigenmann & Eigenmann) (Pisces, Curimatidae) in Juramento reservoir, Minas Gerais, Brazil

2006 ◽  
Vol 23 (2) ◽  
pp. 314-322 ◽  
Author(s):  
Érika R. de Alvarenga ◽  
Nilo Bazzoli ◽  
Gilmar B. Santos ◽  
Elizete Rizzo
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Sexual Maturation ◽  
Nutrient Recycling ◽  
Reproductive Activity ◽  
Feeding Habit ◽  
Southeastern Brazil ◽  
Short Rainy Season ◽  
Probable Role ◽  
Energetic Reserves

Reproductive biology and feeding of Curimatella lepidura (Eigenmann & Eigenmann, 1889) were studied in Juramento reservoir, São Francisco River basin, Southeastern Brazil. Histological analyses and gonadosomatic indexes revealed females and males in reproductive activity from October to March and total spawning occurring from January to March coupled with the peak of spermiating males. In the dry season, the fishes accumulated energetic reserves for reproduction during a short rainy season. The species presented sexual dimorphism, being females larger than males and sexual maturation occurring close to 7.7 cm standard length for females and 7.1 cm for males. C. lepidura presented iliophagous feeding habit, ingesting mainly sediment/detritus and a small amount of acari, algae, Tricoptera insects and Ostracoda crustaceans, suggesting a probable role in nutrient recycling of the Juramento reservoir.

Reproductive biology of the false coral snake Oxyrhopus guibei (Colubridae) from southeastern Brazil

2002 ◽  
Vol 23 (4) ◽  
pp. 495-504 ◽  
Author(s):  
Otavio Marques ◽  
Lígia Pizzatto
Keyword(s):  
Body Size ◽  
Reproductive Biology ◽  
Rainy Season ◽  
Reproductive Activity ◽  
Climatic Conditions ◽  
Southeastern Brazil ◽  
Coral Snake ◽  
Males And Females ◽  
Reproductive Cycles ◽  
Number Of Individuals

AbstractThe reproductive biology of the false coral snake, Oxyrhopus guibei, was studied through dissection of 496 specimens, combined with observations on captive individuals. Males mature with smaller body size than females, females attain much larger body size, and male-male combat is not expected. Clutch size ranged from 3 to 20, and was correlated with female length. Reproductive cycles in both males and females seem to be continuous, with vitellogenesis and spermatogenesis occurring throughout the year. Reproductive activity in both sexes decreased at the end of the rainy season possibly due to previous intense reproductive activity in more favorable climatic conditions. The smaller number of individuals collected at the end of the rainy season apparently occurs due to the decrease of reproductive activity of this snake.

Aspects of the reproductive biology of Physalaemus cuvieri (Anura: Leptodactylidae) in northeastern Brazil

1995 ◽  
Vol 16 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Larissa Barreto ◽  
Gilda V. Andrade
Keyword(s):  
Reproductive Biology ◽  
Reproductive Activity ◽  
Northeastern Brazil ◽  
Southeastern Brazil ◽  
Territorial Behaviour ◽  
Open Area ◽  
Reproductive Tactics ◽  
Male And Female ◽  
Calling Activity ◽  
Physical Interactions

AbstractObservations were made on the reproductive biology of Physalaemus cuvieri from open area habitat in São Luis, MA, Brazil, from August 1988 to August 1989. The reproductive tactics are compared to those of the same species in southeastern Brazil. Vocalization and reproductive activity were restricted the rainy season (January to June), with peaks of activity during late March and early April. Nocturnal calling activity turn was prolonged, with little variation in the number of individual calling during the night. The presence of communal foam nests suggests non-territorial behaviour in this species. However, males called from the same sites all night long. They showed differentiated vocalizations or antiphony, and aggressive physical interactions, which suggests that there may be some territorial behaviours in males. The remainder of the territorial behaviour is related to persistence of the invading male. Satellite behaviour, females mate choice, and a stereotyped behaviour (e.g. quick circular movement of both male and female) prior to amplexus, were also associated with territoriality.

Reproductive Biology and Sexual Dimorphism of Gymnophthalmus vanzoi (Squamata, Gymnophthalmidae) in a Population South of the Amazon River, Brazil

2020 ◽  
Vol 2020 (15) ◽  
pp. 30
Author(s):  
Maiume Silva-da-Silva ◽  
Danilo Augusto Almeida-Santos ◽  
Síria Ribeiro ◽  
Renato Sousa Recoder ◽  
Alfredo P. Santos
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Amazon River

scholarly journals Population biology of the crab Armases angustipes (Crustacea, Decapoda, Sesarmidae) at Brazilian tropical coast

2014 ◽  
Vol 104 (2) ◽  
pp. 150-161 ◽  
Author(s):  
Marina de Sá Leitão C. de Araújo ◽  
Deusinete de O. Tenório ◽  
Daniela da S. Castiglioni
Keyword(s):  
Population Structure ◽  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Population Biology ◽  
Carapace Width ◽  
Reproductive Activity ◽  
Coastal Regions ◽  
Phytoplankton Productivity ◽  
Number Of Individuals ◽  
Tropical Coast

The semi terrestrial crabs are important elements of the fauna of coastal regions. The aim of this study was to analyze the population structure of Armases angustipes (Dana, 1852) at estuaries of the Ariquindá River, considered a non impacted area, and Mamucabas River, considered a few impacted area, on the south coast of state of Pernambuco, Brazil. The species occurred in all months of the year. The number of individuals per month varied, being higher in the months of transition between the seasons. This is probably due to significant seasonal variations of air and burrow temperature and burrow salinity. There was no sexual dimorphism in size of A. angustipes in the mangrove of Ariquindá River, but males were larger than females in the mangrove of Mamucabas River. In both estuaries, the sex ratio did not differ from Mendelian proportion, but showed a deviation for females. The analysis of temporal variation in sex ratio showed significant differences in some months of the year. These variations are due to cyclical events that act distinctly on each sex. In both estuaries, size classes of carapace width were equally represented by both sexes. The ovigerous females of A. angustipes occurred only in some months of the year, especially in summer, in both estuaries. Probably the high phytoplankton productivity observed in summer favors the reproductive activity, since these algae serve as food for the larvae. Specimens of the population of Rio Ariquindá are largest and wider than those of Mamucabas River. This fact, associated with the low abundance of crabs and the lower frequency of ovigerous females observed in Mamucabas River, is an indication that this population may be influenced by the environmental impacts that this estuary has received.

scholarly journals Intertidal life: field observations on the clingfish Gobiesox barbatulus in southeastern Brazil

2011 ◽  
Vol 9 (1) ◽  
pp. 233-240 ◽  
Author(s):  
Tiago H. S Pires ◽  
Fernando Z Gibran
Keyword(s):  
Developmental Stages ◽  
Feeding Activity ◽  
Single Layer ◽  
Egg Laying ◽  
Reproductive Season ◽  
Feeding Habit ◽  
Southeastern Brazil ◽  
Field Observations ◽  
Nocturnal Feeding ◽  
Particulate Feeding

The clingfish Gobiesox barbatulus shows nocturnal feeding activity, spending most part of the day stationary and adhered to the inferior part of stones. To feed, this species uses the sit-and-wait and particulate feeding tactics. It shows a carnivorous feeding habit mostly consuming small benthic crustaceans. It can move in two ways: (1) "stone-by-stone", sliding its ventral sucker disc across each stone and (2) "surf", when it takes advantage of the energy of the ebbing tide to quickly cross a distance up to four times its body length. Its reproductive season occurs between the end of spring and the beginning of summer, during which time it lays about 2,000 adhesive eggs of 1 mm each in a single layer under stones. It has more than one egg-laying session per reproductive season, therefore showing several different developmental stages. It performs fanning, mouthing and guarding of the eggs as forms of parental care. Data shown here also indicates that G. barbatulus has some shelter fidelity, being probably territorial.

scholarly journals Distribution and reproductive biology of the Electric ray Discopyge tschudii Heckel, 1846 in San Matías Gulf, Northern Patagonia, Argentina

2011 ◽  
Vol 9 (4) ◽  
pp. 831-838 ◽  
Author(s):  
Marilú Estalles ◽  
Nidia Marina Coller ◽  
Edgardo Ernesto Di Giácomo ◽  
María Raquel Perier
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Southern Chile ◽  
Southern Brazil ◽  
Southwest Atlantic ◽  
Aggregate Distribution ◽  
Northern Patagonia ◽  
Southeast Pacific ◽  
Discopyge Tschudii

The Electric ray Discopyge tschudii is distributed in the Southwest Atlantic from southern Brazil to southern Argentina and in the Southeast Pacific from Peru to southern Chile. The main threat to this species is fishing. Discopyge tschudii is noncommercial and individuals caught are discarded on board. The present study analyzes the distribution and the morphological and reproductive characteristics of this ray in San Matías Gulf (SMG), Argentina. A total of 1087 individuals were analyzed. The species presented an aggregate distribution, with the main concentrations in the northern and eastern areas of SMG, at depths below 100 m. Males ranged from 9 to 43 cm and females from 11 to 38 cm. The species presented sexual dimorphism. Males were larger and heavier than females and also matured at larger sizes. Size at 50% of maturity was estimated at 30 cm for males and 21 cm for females. A total of 199 embryos were sampled and the proportion of sexes showed no significant differences from the expected 1:1. The number of embryos per female varied from 1 to 12. The most frequent values were 2 and 5. Length at birth was estimated at 82.17 ± 3.87 mm. Based on our findings, we hypothesize that the electric ray D. tschudii completes its reproductive cycle in SMG.

scholarly journals Reproductive biology of Sympterygia bonapartii (Chondrichthyes: Rajiformes: Arhynchobatidae) in San Matías Gulf, Patagonia, Argentina

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
María L. Estalles ◽  
María R. Perier ◽  
Edgardo E. Di Giácomo
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Early Spring ◽  
Egg Laying ◽  
Reproductive Pattern ◽  
Reproductive Parameters ◽  
Egg Capsules ◽  
Northern Patagonia ◽  
Total Length

ABSTRACT This study estimates and analyses the reproductive parameters and cycle of Sympterygia bonapartii in San Matías Gulf, northern Patagonia, Argentina. A total of 827 males and 1,299 females were analysed. Males ranged from 185 to 687 mm of total length (TL) and females from 180 to 742 mm TL. Sexual dimorphism was detected; females were larger, heavier, exhibited heavier livers, wider discs and matured at lager sizes than males. Immature females ranged from 180 to 625 mm TL, maturing females from 408 to 720 mm TL, mature ones from 514 to 742 mm TL and females with egg capsules from 580 to 730 mm TL. Immature males ranged from 185 to 545 mm TL, maturing ones from 410 to 620 mm TL and mature males from 505 to 687 mm TL. Size at which 50% of the skates reached maturity was estimated to be 545 mm TL for males and 594 mm TL for females. According to the reproductive indexes analysed, S. bonapartii exhibited a seasonal reproductive pattern. Mating may occur during winter-early spring and the egg-laying season, during spring and summer.

scholarly journals Morphology of the franciscana (Pontoporia blainvillei) off southeastern Brazil: sexual dimorphism, growth and geographic variation

2002 ◽  
Vol 1 (1) ◽  
Author(s):  
R. M. A. Ramos ◽  
A. P. M. Di Beneditto ◽  
S. Siciliano ◽  
M. C. O. Santos ◽  
A. N. Zerbini ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Geographic Variation ◽  
Southeastern Brazil ◽  
Pontoporia Blainvillei
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