The spiny lobster, Jasus lalandei (H. Milne-Edwards), in South Australia. II. Reproduction

1964 ◽  
Vol 15 (2) ◽  
pp. 133 ◽  
Author(s):  
DR Fielder
Keyword(s):  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Spiny Lobster ◽  
South Australia ◽  
Indirect Evidence ◽  
Ovarian Cycle ◽  
Microscopic Structure ◽  
Stages Of Development ◽  
Size At Sexual Maturity ◽  
Female Reproductive Cycle

The female reproductive cycle is described in detail. The ovarian cycle passes through seven stages of maturation, recognized by changes in macroscopic and microscopic structure. The presence of ovigerous setae in females has been used to estimate size at sexual maturity; these setae are developed fully only at the maturity moult. No stages of development could be described for the testis from macroscopic or microscopic examinations. The structure of the testis and the process of spermatogenesis are described and compared with results obtained by Matthews (1951) for Panulirus pencillatus (Oliver). No simple indication of sexual maturity was found for males, but an estimate was made using other, indirect, evidence.

Reproductive cycle and size at sexual maturity of the commercial whelk Buccinum isaotakii in Funka Bay, Hokkaido, Japan

2003 ◽  
Vol 83 (6) ◽  
pp. 1287-1294 ◽  
Author(s):  
Anthony S. Ilano ◽  
Katsuaki Fujinaga ◽  
Shigeru Nakao
Keyword(s):  
Seminal Vesicle ◽  
Digestive Gland ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Reproductive Organ ◽  
Egg Laying ◽  
Annual Cycles ◽  
Funka Bay ◽  
Size At Sexual Maturity ◽  
Organ Sizes

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.

scholarly journals Population structure and reproductive cycle of the commercial sea cucumber Holothuria mexicana in Belize

2018 ◽  
Vol 66 (4) ◽  
Author(s):  
Arlenie Rogers ◽  
Jean-François Hamel ◽  
Annie Mercier
Keyword(s):  
Sex Ratio ◽  
Protected Areas ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Sea Cucumber ◽  
Size Structure ◽  
Natural Populations ◽  
Gonad Index ◽  
Size At Sexual Maturity ◽  
Spawning Periods

The population and reproductive biology of the commercial sea cucumber Holothuria mexicana (Ludwig, 1875) was studied in Southern Belize (Caribbean Sea), including the sex ratio, size at sexual maturity and reproductive cycle, as well as the size structure among habitats located inside and outside protected areas. Individuals found inside marine protected areas were consistently larger than individuals found outside these boundaries. The male:female sex ratio was 1.1:1.0 with a unimodal size distribution composed mainly of sexually mature individuals (87 %). Size at sexual maturity was established to be ~10 cm based on measures of gamogenetically mature individuals during the peak of the gametogenic maturity period. Juveniles and small adults measuring ≤ 15 cm (13 %), were collected exclusively in sandy and muddy areas of seagrass habitats associated with mangroves. Larger adults were commonly found on hard substrates in both seagrass-associated and coral-reef-associated habitats. Based on histology and gonad indices, the first sign of early gametogenesis was detected in August in both sexes. Gametes developed and matured throughout the colder months between November and February. Decreases in gonad index in both years suggest annual spawning, starting in March-April 2014 (single major event) and March-April and July-August 2015 (two smaller events) for both males and females. The spawning periods were correlated with warmer or increasing temperatures, low rainfall and increasing or high chlorophyll-a concentrations. These data will hopefully guide management and protection of the natural populations of H. mexicana, which are already suffering from overfishing in Belize and neighboring countries. 

Reproductive cycle and size-dependent spawning of female spiny lobsters (Panulirus japonicus) off Oshima Island, Tokyo, Japan

1997 ◽  
Vol 48 (8) ◽  
pp. 869 ◽  
Author(s):  
Megumi Minagawa
Keyword(s):  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Logistic Model ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Spiny Lobster ◽  
Spawning Season ◽  
Size Dependent ◽  
Spiny Lobsters ◽  
Panulirus Japonicus

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.

scholarly journals Female reproductive cycle of the snaked-eyed Lizard Ophisops elegans Ménétriés, 1832 (Reptilia: Lacertidae) from Lebanon

2019 ◽  
Author(s):  
Fida Nassar ◽  
Souad Hraoui-Bloquet
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Reproductive Activity ◽  
Male Adult ◽  
Female Body Size ◽  
Significant Difference ◽  
Ophisops Elegans ◽  
Female Reproductive Cycle

We studied the female reproductive cycle of a population of Ophisops elegans lizard from the herpetology collection of the Natural History Museum of the Lebanese University. Females collected during spring and summer showed vitellogenesis in their ovaries with oviposition occurring from May to July followed by a subsequent quiescent period. They produced up to two clutches. Mean clutch size was 3.2 ± 1, range 2-5 eggs. Clutch size was independent of female body size. The smallest female attaining sexual maturity had a snout vent length of 45 mm. Sexual maturity can be attained within one year of age. We found no significant difference in body size between female and male adult lizards. Seasonal variations in the reproductive activity of females were well synchronized with those of males. 

Size structure and reproductive variation of the spiny lobster Panulirus homarus over a relatively small geographic range along the Dhofar coast in the Sultanate of Oman

1997 ◽  
Vol 48 (8) ◽  
pp. 1085 ◽  
Author(s):  
R. Mohan
Keyword(s):  
Sexual Maturity ◽  
Carapace Length ◽  
Size Structure ◽  
Spiny Lobster ◽  
Reproductive Potential ◽  
Size Class ◽  
Sultanate Of Oman ◽  
Study Region ◽  
Fishery Exploitation ◽  
Size At Sexual Maturity

This paper reports variations in size structure, size at sexual maturity, and reproductive potential in the Panulirus homarus population sampled from commercial catches at three sites: Shuwamiyah, Sudh and Mugsyl along the Dhofar coast in the Sultanate of Oman. The size structure of the lobster population showed significant variation (P < 0.001) among the three sites. Size at sexual maturity, based on the presence of spermatophores or an ovigerous condition, indicated variation within the population. Females mature at a smaller size at Shuwamiyah than they do at Sudh and Mugsyl. The relationship between the number of eggs (E) and carapace length (L, in mm) of female lobsters is expressed by E = –249322 + 8942L (r2 = 0.95; n = 11) over the size range 65–95 mm carapace length. Length frequency, size at sexual maturity, and fecundity were used to estimate the index of reproductive potential (IRP) of each 5-mm size class. The size class with the highest IRP varied among the three sites. The variation in size structure and size at sexual maturity was explained by fishery exploitation and by different oceanographic and ecological conditions caused by seasonal upwelling in the study region.

Reproductive cycle of the Manila clam (Ruditapes philippinarum): an intensively harvested invasive species in the Tagus Estuary (Portugal)

2017 ◽  
Vol 98 (7) ◽  
pp. 1645-1657 ◽  
Author(s):  
Paula Moura ◽  
Paulo Vasconcelos ◽  
Fábio Pereira ◽  
Paula Chainho ◽  
José Lino Costa ◽  
...  
Keyword(s):  
Invasive Species ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Ruditapes Philippinarum ◽  
Manila Clam ◽  
Tagus Estuary ◽  
Gonad Maturation ◽  
Oocyte Diameter ◽  
Ruditapes Decussatus ◽  
Spawning Period

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.

scholarly journals Use of otoliths to estimate size at sexual maturity in fish

2000 ◽  
Vol 43 (4) ◽  
pp. 437-440 ◽  
Author(s):  
Carlos Sérgio Agostinho
Keyword(s):  
Sexual Maturity ◽  
Line Segments ◽  
Alternative Method ◽  
Straight Line ◽  
Size At Sexual Maturity

The viability of an alternative method for estimating the size at sexual maturity of females of Plagioscion squamosissimus (Perciformes, Sciaenidae) was analyzed. This methodology was used to evaluate the size at sexual maturity in crabs, but has not yet been used for this purpose in fishes. Separation of young and adult fishes by this method is accomplished by iterative adjustment of straight-line segments to the data for length of the otolith and length of the fish. The agreement with the estimate previously obtained by another technique and the possibility of calculating the variance indicates that in some cases, the method analyzed can be used successfully to estimate size at sexual maturity in fish. However, additional studies are necessary to detect possible biases in the method.

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