scholarly journals Reproductive biology of blue swimming crab, Portunus segnis (Forskal, 1775) in Yumurtalık Cove, Northeastern Mediterranean, Turkey

2017 ◽  
pp. 424 ◽  
Author(s):  
CANAN TURELI ◽  
IREM NUR YESILYURT

Blue swimming crab, Portunus segnis is a Lessepsian migrant into the Mediterranean and little is known about the biology of it in Iskenderun Bay, Northeastern Mediterranean, Turkey. In the present study the sex ratio, gonadal development stages, gonadosomatic index, size at first sexual maturity, and the fecundity of P. segnis were examined. The specimens of P. segnis were collected monthly from July 2014 to June 2015 (except February) with trawl net from the Yumurtalık Cove. The crabs were found throughout the year and were abundant between July to October (74%). Carapace width range of all samples was between 38.1-163.17 mm, and body weight ranged from 3.46-324.36 g. The population sex ratio was obtained Male:Female=0.7:1 which showed more abundant female population. Fifty percent of the female crabs attained sexual maturity when they reached the sized of 115-119.99 mm CW. The ovigerous female crabs ranging between 101.39- 154.03 mm CW can produced 139379 to 2745236 eggs. The mean fecundity of P. segnis was 1070425±580978 eggs with a mean carapace width of 130.04±12.77 mm. In Yumurtalık Cove, breeding season of P. segnis were observed throughout the year, except winter. Further studies are needed for assessing the reproductive biology of blue crabs in other locations of Turkey.

2019 ◽  
Vol 66 (1) ◽  
Author(s):  
C. Viswanathan ◽  
M. Pravinkumar ◽  
T.V. Suresh ◽  
V. Elumalai ◽  
S.M. Raffi

The present study was conducted to assess the size distribution, sex ratio, size at first sexual maturity, fecundity and spawning season of the commercially important orange mud crab Scylla olivacea (Herbst, 1796) in Pichavaram mangroves in south-east India. This study is the first contribution to the knowledge of reproductive biology of S. olivacea from the Indian coast. Size distribution analysis in the fishery revealed the irrational exploitation of undersized S. olivacea. The estimated sex ratio deviated from equality, being 1:0.87, revealing a male domination. Size at first sexual maturity was determined to be 87 mm in carapace width (CW) in females. Fecundity ranged from 1.16 to 3.53 million in females of 76 to 135 mm CW. Breeding takes place year-round with a peak in pre-monsoon, indicating that it is a prolific breeder. Results revealed that immature individuals of S. olivacea contributed significantly to the catches and thus an effective management of the resource by framing minimum legal size is crucial so that the females are allowed to spawn at least once prior to capture.


Author(s):  
Huynh Minh Sang ◽  
Le Thi Thu Thao ◽  
Ho Son Lam ◽  
Phan Minh-Thu

The reproductive biology of the land crab Gecarcoidea lalandii was documented for the Ly Son Island, Quang Ngai Province, Vietnam. Approximately 30 crabs, collected every month in the 12-month period from August 2019 to July 2020, were analyzed gonadal development stages, sex ratio, spawning season, fecundity and size at first sexual maturity. Results showed that number of male and female crab in nature was not significantly different. Gonadal of the crab passed through five stages of maturation. The crab spawns continuously during the spawning season. In nature, the crab can mature whole year-round with a higher proportion from January to August and the peak maturation from June to July.  The spawning season is of this species is only on the raining period from June to July. Length at first sexual maturity of the crab was 53.91 mm of carapace width for female and 50.39 mm male crab. The absolute fecundity varied in 473,000-820,000 eggs ind-1 and highly related to body weight. The current findings provide the scientific foundation for fishery resource management and artificial breeding of the land crab in Ly Son.


2020 ◽  
Vol 40 (6) ◽  
pp. 746-755
Author(s):  
Ernesto López-Uriarte ◽  
Fernando Vega-Villasante ◽  
Ingo S Wehrtmann ◽  
Edilmar Cortés-Jacinto ◽  
Marcelo U García-Guerrero ◽  
...  

Abstract We analyzed the reproductive cycle of females of the palaemonid shrimp Macrobrachium tenellum (Smith, 1871) collected in the Ameca River, between the Jalisco and Nayarit states, Mexico. We studied the seasonal occurrence of ovigerous females during the year, their relationship with abiotic factors, and the size of the first sexual maturity. The study included 7,100 specimens of M. tenellum, of which 2,791 (39.3%) were males, 3,559 (50.1%) females, and 750 undifferentiated (10.6%). The sex ratio of the total (male-female) population differed significantly from the expected 1:1 with more females. A total of 309 females carried eggs (8.7% of all collected females). Ovigerous females, which were collected in three of the four sampling sites, were found almost year-round (with the exception of March and December), and their number showed a significant positive correlation with water temperature and rainfall. The size of first maturity (TL50%) for all collected females was 55.7 mm total length (TL), ranging from 64.3 mm TL to 42.7 mm TL. The results revealed that the population of M. tenellum in the Ameca River has a continuous reproductive period associated with the rainy season and increasing water temperature.


2018 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Ismaïla NDIAYE ◽  
Alassane SARR ◽  
Alioune FAYE ◽  
Modou THIAW ◽  
Malick DIOUF ◽  
...  

In this study, a total of 1068 specimens Sardinella aurita of which 553 females and 515 males were examined. The objectif of this study was to determine the reproductive parameters of Sardinella aurita. The sex ratio was significantly in favor of females (55%). The size at first sexual maturity was estimated at 18.9 cm for females and 18.0 cm for males. The monthly variation of sexual maturity stages and gonado-somatic index (GSI) allowed to locate the reproduction periods from February to June and from September to December. The mean absolute fecundity was estimated at 110.794 ± 7582 oocytes whereas relative fecundity was about 422 ± 26 oocytes per gram of female.


2019 ◽  
pp. 113-119
Author(s):  
Ahamed Ahamed ◽  
Faruque Ahmed Zoarder ◽  
Jun Ohtomi

Some biological parameters of Salmostoma bacaila – including sex ratio, length-frequency distributions (LFDs), size at sexual maturity, spawning season, length-weight relationships (LWRs) and condition factor – were studied. Samples were collected seasonally during June 2017 to May 2018 from a tributary of the Payra River. The overall sex ratio was significantly different from the expected value of 1:1 (p < 0.001), in favour of male specimens. Females were significantly larger than males. Size at sexual maturity was estimated at 7.6~7.7 cm total length. Seasonal variations in the gonadosomatic index (GSI) indicate that the main spawning season is from spring to summer. The LWRs showed negative allometric growth in both sexes, but with clear seasonal variation. Fulton’s condition factor varied in both sexes and was attributed to variations in GSI with maturity. The fin¬dings of this study will be helpful for management and conservation of S. bacaila populations.


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.


2003 ◽  
Vol 60 (6) ◽  
pp. 1335-1341 ◽  
Author(s):  
Ana Veríssimo ◽  
Leonel Gordo ◽  
Ivone Figueiredo

Abstract A total of 871 females (76–122 cm) and 86 males (68–100 cm) of Centroscymnus coelolepis caught in Portuguese mainland waters were examined for reproductive characteristics. One hermaphroditic individual of 95 cm was found. Males were few in numbers and dominated by immature specimens. Female length at first sexual maturity was 98.5 cm. Mean ovarian and uterine fecundity were 13.2 oocytes per female and 9.9 embryos per pregnant female, respectively. Total length of embryos with completely absorbed external yolk sacs ranged between 233 and 300 mm. Sex ratio (F/M) of embryos with completely absorbed external yolk sac was 0.9. All stages of reproduction were found during the 12-month sampling period. Results were compared with those from other regions. A hypothesis is formulated on the existence of several regional populations based on morphometric and reproductive parameters observed in different areas.


2013 ◽  
Vol 93 (8) ◽  
pp. 2235-2246 ◽  
Author(s):  
Ibtissem Louiz ◽  
Mossadok Ben Attia ◽  
Oum Kalthoum Ben Hassine

The rock goby, Gobius paganellus one of the most common gobiid fish in Bizerta lagoon (north-east of Tunisia), is a gonochoric species that belongs to the Gobiidae family. This study provides the first detailed information of its reproductive biology in lagoon environments. Gobius paganellus was sampled monthly from January 2005 to December 2006 involving 1486 specimens. Total length distribution ranged between 38 and 125 mm. The maximum recorded total lengths were, respectively, 122 mm and 125 mm for female and male. Over the entire population, the sex-ratio was unbalanced in favour of females. According to months, a predominance of females sex-ratio was recorded during the spawning period while according to body size, males were dominating among larger size-classes. In both sexes, the variation of the gonadosomatic index (GSI) was independent of size. Macroscopic and microscopic examination of the gonads added to the monthly monitoring of gonadosomatic index and hepatosomatic index showed that gonads development begins in October and spawning period extends from December to March. The cyclic pattern of gonads development was determined by histology. Results indicated that G. paganellus exhibits a group-synchronous oocyte development. The sizes of first sexual maturity related to 50% of mature individuals were 78.3 mm (CI95: 77–84 mm) for males and 79 mm (CI95: 75–85 mms) for females. The discussion part underlined the impacts of some environmental factors and antropization of this lagoon on sexual cycle of G. paganellus.


2015 ◽  
Vol 75 (1) ◽  
pp. 198-207 ◽  
Author(s):  
MR. Oliveira ◽  
MM. Carvalho ◽  
NB. Silva ◽  
ME. Yamamoto ◽  
S. Chellappa

The epipelagic flyingfish, Hirundichthys affinis is a major artisanal fishery resource from the Northeastern coastal waters of Brazil. However, biological information about this species has been poorly documented. This paper presents data on the length-weight relationship, sex ratio, length at first sexual maturity, gonadal development and fecundity of H. affinis sampled from the coastal waters of Rio Grande do Norte, Brazil. The total body length and weight for both sexes ranged from 23.4 to 29.4 cm and from 89 to 188g, respectively. The allometric coefficient of males was 2.208 and that of females was 2.985, indicating negatively allometric growth. The sex ratio was 1M:1.6F thus differing from the expected ratio of 1:1 (χ2 = 18.63). The total length at first sexual maturity was estimated at 27.3 cm for males and 27.1 cm for females. The macroscopic characteristics of the gonads indicated four maturation stages. Histological studies of gonads of H. affinis showed seven phases of oocyte development and four phases of spermatocyte development. The mean absolute fecundity was 9092 vitelogenic oocytes. Spawning occurred during the months of March to July. The microscopic descriptions of the stages of gonad maturation indicate that the study area is an important spawning ground of H. affinis.


2014 ◽  
Vol 65 (11) ◽  
pp. 1035 ◽  
Author(s):  
D. P. Veras ◽  
F. H. V. Hazin ◽  
I. S. L. Branco ◽  
M. T. Tolotti ◽  
G. H. Burgess

From October 2005 to March 2010, a total of 480 pelagic stingray, Pteroplatytrygon violacea, specimens, 188 females and 292 males (0.64 female : 1 male), were taken in the equatorial and south-western Atlantic by the commercial tuna longline fishery and their reproductive biology was studied. Disc widths (DW) ranged from 28.0 to 66.0 cm for females and from 34.0 to 59.6 cm for males. Size at first sexual maturity was estimated at ~48.0 cm DW (first pregnant female) for females and ~41.0 cm DW for males. Ovarian fecundity, considering only follicles larger than 0.5 cm in diameter, ranged from 1 to 17 follicles per female, while the uterine fecundity of embryos in pregnant females in Stages 2 and 3 ranged from 1 to 5 embryos per female. The sex ratio between the embryos was almost equal (1.08 female : 1 male) and the size at birth was 19.0 cm DW.


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