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.

Contrasting sizes at sexual maturity of southern rock lobsters (Jasus edwardsii) in the two Victorian fishing zones: implications for total egg production and management

1997 ◽  
Vol 48 (8) ◽  
pp. 1009 ◽  
Author(s):  
D. K. Hobday ◽  
T. J. Ryan
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Carapace Length ◽  
Reproductive Potential ◽  
Size Class ◽  
Commercial Catch ◽  
Size Classes ◽  
Eastern Zone ◽  
Jasus Edwardsii ◽  
Western Zone

Fecundity (F) of Jasus edwardsii Hutton (Decapoda:Palinuridae) in the two Victorian fishing zones (Eastern and Western) was estimated from egg masses collected from 98 mature females (97–164 mm carapace length, CL) and was found to be related to carapace length (CL) by the equation F = 0·0316L3.359 (r2 = 0·8539; n = 571). Size at onset of sexual maturity (SOM), estimated from samples of the commercial catch (n = 3891) and analysed to determine the smallest size class in which 50% of females were carrying eggs or possessed ovigerous setae, was lower in the Western Zone (90 mm CL) than in the Eastern Zone (112 mm CL). Fecundity and SOM estimates and length frequencies in the commercial catch were used to estimate the relative reproductive potential (RRP) of each 5-mm-CL size class. The maximum RRP in the Western Zone was attributed to the size classes of 105 (38%) and 110 mm CL (25%), whereas the maximum RRP in the Eastern Zone was attributed to the size classes between 130 (40%) and 135 mm CL (16%). This study indicates that the current minimum legal size limits need to be reassessed and that separate management strategies for the two zones need to be considered.

scholarly journals A comparison of the allometric growth in Uca leptodactyla (Crustacea: Brachyura: Ocypodidae) from two subtropical estuaries

2004 ◽  
Vol 84 (4) ◽  
pp. 733-735 ◽  
Author(s):  
Rosana Carina Flores Cardoso ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Growth Pattern ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Brazilian Coast ◽  
Allometric Growth ◽  
Size At Sexual Maturity ◽  
Subtropical Estuaries ◽  
Habitat Similarity

The allometric growth of Uca leptodactyla from two distinct subtropical estuaries on the Brazilian coast was evaluated concerning its growth pattern and size at onset of sexual maturity. Females attained maturity at similar sizes in both sites (4·1 mm of carapace length in Indaiá and 4·2 mm in Ubatumirim), while males differed slightly. They reached the size at sexual maturity of 5·3 mm of carapace length in Indaiá and 4·6 mm in Ubatumirim. Growth pattern is usually similar among crabs from distinct sites while size at sexual maturity is frequently different. However, in the case of U. leptodactyla it did not occur, probably due to the strong habitat similarity and intrinsic features of this species.

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. 

scholarly journals Size at morphological maturity of Ucides cordatus (Linnaeus, 1763) (Brachyura, Ocypodidae) in the Laranjeiras Bay, Southern Brazil

2005 ◽  
Vol 48 (1) ◽  
pp. 139-145 ◽  
Author(s):  
Glaucia Dalabona ◽  
Jayme de Loyola e Silva ◽  
Marcelo Antonio Amaro Pinheiro
Keyword(s):  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Carapace Width ◽  
Southern Brazil ◽  
Monthly Basis ◽  
Ucides Cordatus ◽  
Size At Sexual Maturity ◽  
Males And Females ◽  
One Year

Morphometry and maturity of Ucides cordatus were analyzed with males and females collected during one year on a monthly basis at Laranjeiras Bay, Paraná State, Brazil. Carapace length, chelipeds propodus length and abdominal width were measured and related to carapace width to verify sexual dimorphism and size at morphological maturity of each sex. Carapace and propodus length of larger and smaller cheliped presented difference between sexes, confirming the use of both as secondary sexual characters. MATURE II program indicated 44mm and 43mm of carapace width to represent the size at sexual maturity of males and females, respectively.

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.

Size At Sexual Maturity in Red Shrimp Females, Aristaeomorpha Foliacea, From the Sicilian Channel (Mediterranean Sea)

Crustaceana ◽  
1995 ◽  
Vol 68 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Marco L. Bianchini ◽  
Sergio Ragonese
Keyword(s):  
Logistic Model ◽  
Sexual Maturity ◽  
Reproductive Potential ◽  
Sigmoid Curve ◽  
Size At Sexual Maturity ◽  
Aristaeomorpha Foliacea ◽  
Almost All ◽  
Point Of Intersection ◽  
Trawl Surveys ◽  
Sigmoid Shape

AbstractThis paper reports on the maturity pattern and the estimation of length at sexual maturity for Aristaeomorpha foliacea females, based on two years of seasonal research trawl surveys. Two approaches were used: gonadic condition (empirical scale) and presence/absence of spermatophores. Ready-to-spawn females (IV stage) occurred almost exclusively in summer throughout the area surveyed. Distribution of the proportion of "mature" (III + IV stages) females showed the classic "sigmoid" shape but with a general failure to attain 100% maturity, even though in the largest size classes there is substantial inter-year variability. The presence of spermatophorcs, however, being a sign of adulthood, with almost all the medium/large specimens positive, showed a better approximation to the sigmoid curve. An attempt to combine the two curves, in order to more precisely identify the length at maturity, is illustrated and discussed. The logistic model has been chosen in a form that allows the asymptote to be < 1. The maximum reproductive potential is defined as the point of intersection of the two curves (spermatophores and maturity). This maximum is reached after about 18 months, at a carapace length of 40 mm.

Reproductive biology of the slipper lobster Scyllarides deceptor (Decapoda: Scyllaridae) along the southern Brazilian coast

2008 ◽  
Vol 88 (7) ◽  
pp. 1433-1440 ◽  
Author(s):  
Gabriela Oliveira ◽  
Andrea S. Freire ◽  
Paulo R.K. Bertuol
Keyword(s):  
Reproductive Biology ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Egg Size ◽  
Carapace Length ◽  
Sampling Period ◽  
Late Winter ◽  
Brazilian Coast ◽  
Rocky Bottom ◽  
Size At Sexual Maturity

The reproductive biology of Scyllarides deceptor was studied along the southern Brazilian coast (27°S 48°W) from December 2002 to December 2003. Samples were collected monthly at Xavier Island, where animals were caught and marked. Fecundity and egg size were estimated from ovigerous females caught also in two adjacent islands, Arvoredo and Aranhas. A total of 98 females was recorded at Xavier Island during the sampling period, 24 of these were recaptured and presented time-at-liberty ranging from 14 to 297 days. Ovigerous females were observed during spring and summer, with the moulting period lasting from late winter to spring. Size at sexual maturity was assessed from 66 females caught during the breeding season and estimated in 85.33 mm of carapace length (CL). Mean fecundity of S. deceptor was estimated in 191,262 eggs (±17,811, SE) for females, on average, 94.74 mm long (±1.86 mm SE) (CL). Fecundity was significantly related to CL (R2 = 0.90) Mean egg size was 0.67 mm (±0.005 mm SE) and did not correlate significantly to CL (P = 0.78). The rocky bottom of Xavier Island was favourable for reproduction, presenting shelter and foraging grounds for the ovigerous females. For management purposes, our results suggest the closure of the S. deceptor fishery from November to January and the capture-size of females to be restricted to animals larger than 90 mm (CL).

Sexual maturity, reproductive season and fecundity of the spiny lobster Panulirus penicillatus from the Gulf of Eilat (Aqaba), Red Sea

1993 ◽  
Vol 44 (4) ◽  
pp. 527 ◽  
Author(s):  
I Plaut
Keyword(s):  
Red Sea ◽  
Sexual Maturity ◽  
Field Data ◽  
Carapace Length ◽  
Spiny Lobster ◽  
Geographic Range ◽  
Reproductive Season ◽  
Geographic Isolation ◽  
Gonadal Index ◽  
Sexually Mature

Panulirus penicillatus Olivier (1791) (Decapoda: Palinuridae) is widely distributed in the Indian and Pacific Oceans and is the most common spiny lobster in the Red Sea. Female lobsters (n =234), were collected on four occasions in 1986 from the coral reef of Dahab, 110 km south of Eilat, Israel. Field data and the gonadal index indicated that the reproductive season was from February to October, during which the females spawned 2-4 times. In nature, females became sexually mature at a carapace length (CL) of 50 mm. This result was confirmed by morphometric analysis of the regression between pleopodal exopodite length and carapace length. The number of eggs per spawn (E) was related to CL by the equation E=2.715 ×(CL)2.581. The incubation period of eggs was 35.5�1.0 days (�s.d.) at temperatures of 24-27�C in the aquarium. The results are compared with data on P. penicillatus from other parts of its geographic range, and the effect of geographic isolation on reproduction is discussed.

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.

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