Reproductive cycle, sexual maturity and longevity of Odontophrynus americanus (Anura: Odontophrynidae) in South Brazil

2020 ◽  
Author(s):  
Amanda J.C. Brum ◽  
Luiza Loebens ◽  
Cynthia P. A. Prado ◽  
Sonia Z. Cechin
2020 ◽  
Vol 41 (4) ◽  
pp. 445-459
Author(s):  
Luiza Loebens ◽  
Selma Maria Almeida-Santos ◽  
Sonia Zanini Cechin

Abstract We described the reproductive cycle, size-fecundity relationships, reproductive effort, and sexual maturity of Tomodon dorsatus in South Brazil. We examined 87 individuals (25 males and 62 females) from herpetological collections. The description of the reproductive cycle was based on the morpho-anatomical and histological changes in male testes, ductus deferens, and kidney and in female ovary and oviduct. The age at the onset of sexual maturity was estimated by skeletochronology of the caudal vertebra. The reproduction is seasonal semi-synchronous with most of the individuals showing a reproductive peak in the spring. Males and females have developed sperm storage strategies, increasing the reproductive success. Males store sperm in the ductus deferens during the autumn and winter, while females storage takes place in the utero-vaginal junction furrows during the autumn and early winter. Larger females produce a higher number of larger follicles and eggs. Females invest more in growth before reaching sexual maturity than males. Females reach sexual maturity earlier (4 years old) than males (5 years old) and have larger bodies but lower longevity. Reproductive strategies of Tachymenini specie are highly conserved.


2017 ◽  
Vol 98 (7) ◽  
pp. 1645-1657 ◽  
Author(s):  
Paula Moura ◽  
Paulo Vasconcelos ◽  
Fábio Pereira ◽  
Paula Chainho ◽  
José Lino Costa ◽  
...  

The present study aimed to describe the reproductive cycle and estimate the size at sexual maturity of the Manila clam (Ruditapes philippinarum) in the Tagus Estuary (Portugal). Specimens were collected monthly from September 2013 to December 2015 during fishing surveys using bivalve dredges. The gametogenic cycle was described in detail using gonad histology and monitored throughout the study period by the monthly variation in the frequency of gonad maturation stages, mean gonadal index and mean oocyte diameter. This invasive population of R. philippinarum displayed synchronous gonadal development between sexes, with ripening occurring mainly in April and May followed by an extensive spawning period until November–December. Individuals reached the size at first sexual maturity at 29.4 mm in shell length (i.e. before 1 year old). Furthermore, the reproductive strategy, dynamics and potential were compared between the invasive R. philippinarum and the native congeneric carpet shell clam (Ruditapes decussatus). Overall, the data gathered in this study constitutes valuable baseline information to propose conservation strategies and implement management measures to minimize the harmful impacts caused by this invasive species on local ecosystems and native biodiversity, particularly over populations of autochthonous bivalves.


2011 ◽  
Vol 27 (5) ◽  
pp. 1190-1196 ◽  
Author(s):  
R. Sánchez-Cárdenas ◽  
M. Arellano-Martínez ◽  
M. C. Valdez-Pineda ◽  
R. E. Morán-Angulo ◽  
B. P. Ceballos-Vázquez

2019 ◽  
Vol 14 (1) ◽  
pp. 1 ◽  
Author(s):  
Vinícius Matheus Caldart ◽  
Luiza Loebens ◽  
Amanda Jamile Carvalho Brum ◽  
Lívia Bataioli ◽  
Sonia Zanini Cechin

1989 ◽  
Vol 1 (3) ◽  
pp. 255 ◽  
Author(s):  
KB Karim ◽  
S Banerjee

At and near Agra, in Uttar Pradesh, India, R. h. hardwickei had a strictly defined annual reproductive cycle. Although many females were inseminated during late February to mid April, ovulation was not recorded until 11 March. Progressively more females ovulated and conceived during the following weeks until the end of April and released one ovum from either of the ovaries with nearly equal frequency. A single conceptus was carried in the ipsilateral uterine cornu during each cycle. The gestation period was 95-100 days. Births occurred between the second week of June and the end of July. Lactation lasted at least 20 days. Females attained sexual maturity at an age of 8.5-9.0 months. Males took at least 16-17 months to attain sexual maturity. Females were segregated during lactation; during the rest of the year, males and females lived together.


2005 ◽  
Vol 26 (4) ◽  
pp. 527-533 ◽  
Author(s):  
Luís Felipe Schmidt de Aguiar ◽  
Marcos Di-Bernardo

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.


Author(s):  
Anthony S. Ilano ◽  
Katsuaki Fujinaga ◽  
Shigeru Nakao

The reproductive cycle and size at sexual maturity of the commercial whelk Buccinum isaotakii in Funka Bay, southern Hokkaido, Japan, was examined using monthly samples of individuals collected from May 1999 until October 2000. Female and male sexual maturity was determined based on reproductive organ sizes and histological examination, and sex ratios did not differ from parity. There were parallel annual cycles in the size of the ovary and pallial oviduct, and an inverse cycle for the digestive gland. The testis and seminal vesicle showed inverse cycles. The peak in seminal vesicle size was at the same time as the peak in ovary and pallial oviduct. The size of the male digestive gland exhibited no evident cycle. Males were mature from May to October 1999 and from April to October 2000, and spent individuals first appeared in September 1999 and then decreased in numbers until June 2000. Sperm content and epithelium in seminal vesicle indicated that the copulating period started in March and lasted until August 2000. Ovarian maturation and oogenesis occurred from October 1999 onwards and peaked in January 2000, with egg laying occurring from May until September. An increase in temperature coincided with the advancement of spermatogenesis and the egg laying while the transfer of the sperm from the testis to the seminal vesicle in males and the maturation of ovaries in females coincided with a decrease in temperature.


2017 ◽  
Author(s):  
Kazuhiro Ura ◽  
Narumi Takei ◽  
Ichiro Higuchi ◽  
Tomoharu Yuhi ◽  
Osamu Nishimiya ◽  
...  

AbstractBoth female and male sea urchins accumulate the major yolk protein (MYP) in the nutritive phagocytes of immature gonads before gametogenesis, and MYP is the most abundant protein in the coelomic fluid of both sexes. In females, MYP in the coelomic fluid is taken up by the nutritive phagocytes and transported to the growing oocytes. This study examined quantitative changes of MYP in the coelomic fluid of both sexes during the reproductive cycle of wild sea urchins,Mesocentrotus nudus. Levels of MYP in the coelomic fluid of females increased and reached a peak at the histological pre-mature stage of gonad activity (i.e. Stage 3), and positive correlation between the MYP level and the gonadosomatic index (GSI) was observed. In male sea urchins the level of MYP in the coelomic fluid increased at the pre-mature stage, though positive correlation between the MYP level and GSI was not observed. These results indicate that MYP in the coelomic fluid is suitable as a biomarker of the onset and progression of sexual maturity in female sea urchins.


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