Reproductive biology of the commercial sea cucumber Parastichopus californicus (Stimpson) (Echinodermata: Holothuroidea). I. Reproductive periodicity and spawning behavior

1986 ◽  
Vol 64 (1) ◽  
pp. 168-175 ◽  
Author(s):  
J. Lane Cameron ◽  
Peter V. Fankboner

The commercial sea cucumber Parastichopus californicus (Stimpson) has an annual reproductive cycle, with spawning occurring in the late spring through summer within the inland waters of southwestern British Columbia, Canada. The sexes are separate and occur at a 1:1 ratio within the population studied. Ovarian and testicular tubules regenerate and proliferate preceding the spawning season each year. Spawning is partially synchronous and may be mediated by an increase in the intensity and duration of insolation.

1997 ◽  
Vol 48 (8) ◽  
pp. 869 ◽  
Author(s):  
Megumi Minagawa

Reproductive biology of the spiny lobster Panulirus japonicus was histologically examined by monthly sampling between March 1993 and September 1994 at Oshima Island, near Tokyo. P. japonicus had a well defined reproductive cycle. Yolk accumulation became manifest in February and ovaries grew rapidly in March. Females spawned from late April to mid August and were ovigerous to mid September. Of large females with a carapace length (CL) of ≥47 mm, 93% were estimated to spawn twice during the spawning season. Size at which 50% of females reached sexual maturity was estimated to be 41.8 mm CL, as calculated from a logistic model. Some individuals considered to be primiparous showed delayed vitellogenesis and were estimated to spawn only once during the season.


2014 ◽  
Author(s):  
Angus Yeomans ◽  
Nichol Thompson ◽  
Jennifer Castle-Miller ◽  
David O Bates ◽  
Domingo Tortonese

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1729
Author(s):  
Sara Falvo ◽  
Luigi Rosati ◽  
Maria Maddalena Di Fiore ◽  
Federica Di Giacomo Russo ◽  
Gabriella Chieffi Baccari ◽  
...  

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E2) and androgens are higher during the reproductive period compared to the non-reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2-induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt-1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non-reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt-1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad.


2021 ◽  
Author(s):  
Fumihiro Yamane ◽  
Katsuyoshi Suitoh ◽  
Takuji Okumura ◽  
Kenji Toyota ◽  
Naoaki Tsutsui ◽  
...  

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.


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