The cycle of gonad development inPatella vulgata(Mollusca; Gastropoda): The use of oocyte diameter measurements and gravimetric estimates of sexual maturity

Sarsia ◽  
1987 ◽  
Vol 72 (1) ◽  
pp. 29-35
Author(s):  
P.R. Garwood
2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Tridjoko Tridjoko

This study aimed to determine the effect of LHRH-a hormone implantation on gonadal development of humpback grouper, Cromileptes altivelis 2nd generation (F-2). Individuals used were 20 female grouper fish with weight range of 600-800 gram/fish and total length range of 28.0-30.0 cm. The treatment used 5 fish each with tagging. Grouper fishes were stocked into the 75 m3 circular concrete tank. Hormone of LHRH-a with dosage of 50 μg/kg body weight was used as implant treatment of (A) 1 time,, (B) 2 times, (C) 3 times, and (D) without implant. The results showed that implantation of LHRH-a hormone were significantly stimulate gonad development of humpback grouper second generation (F-2). Treatment of 3 times implant every month showed the best results produced  oocyte diameter up to 480 μm, while the control of oocyte diameter only reached <400 μm. Keywords: LHRH-a hormone, implantation, Humpback grouper, gonad development


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.


2017 ◽  
Vol 58 (1) ◽  
pp. 117-125
Author(s):  
Tatjana Dobroslavić ◽  
Renata Mozara ◽  
Branko Glamuzina ◽  
Vlasta Bartulović

The reproductive characteristics of bogue (Boops boops) in the southeastern Adriatic Sea are presented in this study. The analysis is based on 676 specimens caught by seine net from December 2011 to November 2012. Total length of females ranged from 13.3 to 29.3 cm and males from 15.1 to 26.3 cm. The overall sex ratio of females to males was 1:0.85 (χ2=4.314; P &lt; 0.05) with a slightly higher number of females in the largest size class. Length-weight relationship for the total population indicated negative allometric growth (b=2.911). Values of the condition factor are relatively low for both sexes. Maximum values were recorded in September 1.025 for females and 1.029 for males. Gonadosomatic index and histological examination showed that the spawning season of the bogue in the Adriatic is from January to May with peak in February. Six stages of gonad development were identified: immature, undergoing maturation, ripening, ripe, spawning and spent. The monthly distribution of the different sexual maturity stages and the frequency distribution of oocyte diameter revealed that this species is a batch spawner.


Author(s):  
Rosana Mazzoni ◽  
Jaqueline Petito

Aspects of the reproductive biology of one Tetragonopterinae was assessed in the Ubatiba river - Maricá / RJ. Length structure and mean size suggested sexual dimorphism, females reaching larger sizes than males. The onset of sexual maturity occured at 2.8cm for both the sexes. Fecundity, determined on ripe ovaries, showed positive correlation to females size and weight and varied from 595 to 5520 for 3.9cm and 6.2cm lengths respectively. The spawning type, defined as total, was determined by the oocyte diameter frequency from ovaries in different development stages. The frequency distribution of ovarian/testis maturation stages, associated with the temporal variation of the gonadosomatic index, suggested that the reproduction period was prolonged along the whole annual cycle.


2015 ◽  
Vol 75 (2) ◽  
pp. 324-330
Author(s):  
MR. Oliveira ◽  
NB. Silva ◽  
ME. Yamamoto ◽  
S. Chellappa

The gonad development and reproductive aspects of Hemiramphus brasiliensis from the coastal waters of Rio Grande do Norte, Brazil were verified. This paper presents data on the length-weight relationship, sex ratio, length at first sexual maturity, gonad development, reproductive period and fecundity of H. brasiliensis. Females of this species predominated in the sampled population and were larger in size than the males. The length at the first sexual maturation of males was 20.8 cm and that of females was 21.5 cm. The macroscopic characteristics of the gonads indicated four maturation stages. Histological studies of gonads of H. brasiliensis showed six phases of oocyte development and four phases of spermatocyte development. The batch fecundity of this species is 1153 (±258.22) oocytes for 50 g body weight of female. The microscopic characteristics of gonad development indicate that H. brasiliensis is a multiple spawner, with active reproductive period during the months of January to June and October. The reproductive period of this species is independent of the rainy period of the region.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mônica Rocha de Oliveira ◽  
Sathyabama Chellappa

The reproductive aspects ofHemiramphus brasiliensiswere analyzed with a view to verify the temporal dynamics of reproduction. This paper presents data on sex ratio, length at first sexual maturity, macroscopic and histological aspects of gonad development, gonadosomatic index (GSI), reproductive period, and fecundity ofH. brasiliensis. The fishes were captured from the coastal waters of Rio Grande do Norte, northeastern Brazil. Females of this species predominated in the sampled population and were larger in size than the males. The length at the first sexual maturation of males was 20.8 cm and that of females was 21.5 cm. The macroscopic characteristics of the gonads indicated four maturation stages. Histological studies of gonads ofH. brasiliensisshowed six phases of oocyte development and four phases of spermatocyte development. The batch fecundity of this species was 1153 (±258.22) mature oocytes for 50 g body weight of female. The microscopic characteristics of gonad development indicate thatH. brasiliensisis a multiple spawner, presenting a prolonged reproductive period during the whole year, with a peak in the month of April, and is considered as an opportunistic strategist.


Author(s):  
Junyan Bai ◽  
Zhihao Dong ◽  
Zhengyu Fan ◽  
Xinle Wang ◽  
Ying Lei ◽  
...  

Background: GnRH-1 mainly exists in hypothalamus and it is vital to gonad development and sexual maturity of animals. This study mainly analyzed the association between GnRH-1 polymorphism and carcass traits of quails, Research conclusions can provide references for breeding of new species of quail.Methods: From 2018 to 2019, 31 female samples of Chinese Yellow quail, beijingbai quail and Korean quail were collected in Luolong District, Luoyang City, Henan Province, China.SNP mutation sites of GnRH-1 gene were investigated in China yellow quail, Beijing white quail and Korean quail through PCR amplification and DNA sequencing technologys. Moreover, correlation analysis between polymorphism sites of GnRH-1 gene and carcass traits of quail was performed. Result: According to research results, a total of 14 SNP mutation sites of GnRH-1 were detected in China yellow quail, Beijing white quail and Korean quail, which were C71T, C108T, C168T, C178T, A184G, C206T, A209C, C215T, A252G, A279T, C281T, C293G, C339T and C458T. For A209C and C281T, only 2 genotypes were detected in China yellow quail and Beijing white quail, while for the remaining 12 SNP mutation sites, 3 genotypes were detected in three quail species. Correlation analysis showed that A209C, A279T, C281T and C339T were significantly correlated with liver weight (P less than 0.05), A209C, C281T and C339T were significantly correlated with dressing percentage (P less than 0.05), C215T and A279T were significantly correlated with breast muscle weight(whole) (P less than 0.05), A209C was significantly correlated with body weight, dressed carcass weight and whole net carcass weight (P less than 0.05).


2018 ◽  
Vol 70 (1) ◽  
pp. 213-221 ◽  
Author(s):  
G. Failla ◽  
A. Calais Júnior ◽  
L. Pavanelli ◽  
L.C. Nunes

ABSTRACT Studies on reproduction in sea turtles are important due to its life cycle, migratory patterns, high juvenile mortality and environmental impacts. This study aimed to analyse histomorphometrically gonads of C. mydas from the coastline of the Espírito Santo State, Brazil. Ovaries and testicles were collected between 2014 and 2015 from stranded animals. The material was fixed in formalin 10%, assessed macroscopically and processed for histomorphometrical evaluation. Gonads from 34 individuals were evaluated, twenty-four females and ten males. Macroscopic sexual identification presented 100% accuracy confirmed by histology. Sexual dimorphism was observed in one individual, which was considered as adult (CCL=1.023 m). Microscopy of female gonads revealed predominant previtellogenic follicles; oocyte diameter ranged between 161µm and 750µm and a positive correlation between ovarian length, largest oocyte and CCL was found. In males, autolysis was verified in five individuals. Viable testicles revealed predominant spermatogonia, primary spermatocytes and Sertoli cells in the seminiferous tubules and, Leydig cells and fibroblasts in the stroma. There was a positive correlation between tubular diameter and CCL and testicle length and CCL. Maturation of stromal tissue and a positive correlation between tubular lumen and CCL were also observed. Gonad development is proportional to individual growth.


2018 ◽  
Vol 69 (9) ◽  
pp. 1379 ◽  
Author(s):  
Daniela Milano ◽  
Juan P. Barriga

Reproductive characteristics of the native fish Galaxias platei were studied in Lake Moreno, an ultra-oligotrophic deep lake in North Patagonia. According to histological analysis of ovaries, G. platei presents synchronous oocyte development typical of a group-synchronous spawner. Mature oocyte diameter ranged from 1031 to 1419μm. Based on the gonadosomatic index, annual spawning occurs between April and June (austral autumn) and is directly related to the water temperature of deeper strata (below 30m) where this species lives, but not with photoperiod. Female G. platei acquire sexual maturity at a length of 105mm, whereas males acquire sexual maturity at a length of 177mm. Delaying maturity to obtain higher fecundity, as well as maximum body size and longevity, indicates that G. platei is more specialised than the other South American Galaxias, G. maculatus, in terms of lifestyle. These specialised features are related to the stable environment G. platei lives in and indicate that it could eventually become a vulnerable species in unstable environments, such as the Patagonian lakes dominated by salmonids.


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