Reproductive biology ofPhilodryas patagoniensis(Snakes: Dipsadidae) in south Brazil: Female reproductive cycle

2017 ◽  
Vol 99 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Luiza Loebens ◽  
Claudio Augusto Rojas ◽  
Selma Maria Almeida-Santos ◽  
Sonia Zanini Cechin
2016 ◽  
Vol 98 (4) ◽  
pp. 329-339 ◽  
Author(s):  
Luiza Loebens ◽  
Sonia Zanini Cechin ◽  
Tiago Felipe Theis ◽  
Livia Bataioli Moura ◽  
Selma Maria Almeida-Santos

2016 ◽  
Vol 23 (1) ◽  
pp. 28-31
Author(s):  
Gerrut Norval ◽  
Jean-Jay Mao ◽  
Stephen R. Goldberg ◽  
Shao-Chang Huang

We collected 13 (male = 2; female = 10; juvenile = 1) Takydromus formosanus on an ad hoc basis from a Betelnut Palm (Areca catechu) plantation in Santzepu, Sheishan District, Chiayi County, as part of a herpetofaunal survey of the area. The smallest reproductively active female had a snout-vent length (SVL) of 44mm, and the smallest male with an enlarged tail base had a SVL of 41 mm. A histological examination and oviposition indicated that the female reproductive cycle commences in April and lasts until at least June. We recorded no clutch sizes greater than two eggs. Takydromus formosanus is a poorly studied species, and many aspects of the reproductive biology of this species merit further research.


2008 ◽  
Vol 25 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Patrícia Calil ◽  
Carlos A. Borzone

Mysidacea are common sublittoral crustaceans that inhabit all coasts in the world. In this study, the population characteristics and the reproductive biology of Metamysidopsis neritica Bond-Buckup & Tavares, 1992 were studied in the surf zone of a south Brazilian beach (Atami). Mysids were sampled at monthly intervals from August, 1999 to July, 2000 (total of 29,490 individuals). Individuals were classified into six population categories. The highest abundance occurred in May (8,665) and August (6,415), and lowest in September (336) and December (368). Three main generations were identified, namely the summer, fall and winter generations. The winter generation was the longest (four to five months). The fall generation lasted four months, and the summer one extended from three to four months. Ovigerous females occurred throughout the year, with a greater proportion in July. The number of eggs or larvae varied from one to 16. Weak associations were found between female length and egg number, egg volume, and the number of larvae with and without eyes. Egg volume increased during the coldest season, whereas the smallest values were recorded during summer. These results suggest a possible direct relationship between egg volume and generation longevity.


2011 ◽  
Vol 9 (4) ◽  
pp. 831-838 ◽  
Author(s):  
Marilú Estalles ◽  
Nidia Marina Coller ◽  
Edgardo Ernesto Di Giácomo ◽  
María Raquel Perier

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.


Copeia ◽  
1976 ◽  
Vol 1976 (2) ◽  
pp. 256 ◽  
Author(s):  
Dennis Jacob ◽  
L. S. Ramaswami

2020 ◽  
Author(s):  
Amanda J.C. Brum ◽  
Luiza Loebens ◽  
Cynthia P. A. Prado ◽  
Sonia Z. Cechin

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