Maturity, Mating, and Egg Laying in the Spider Crab, Chionoecetes opilio

1970 ◽  
Vol 27 (9) ◽  
pp. 1607-1616 ◽  
Author(s):  
J. Watson
Keyword(s):  
Carapace Width ◽  
Mature Female ◽  
Egg Laying ◽  
Minimum Size ◽  
Spider Crab ◽  
Allometric Growth ◽  
Morphometric Measurements ◽  
Chionoecetes Opilio ◽  
Breeding Potential ◽  
Males And Females

Morphometric measurements and gonad examination of the spider crab, Chionoecetes opilio, showed that 50% maturity occurred at about 57 and 50 mm carapace width for males and females, with minimum sizes at maturity of 51 (males) and 47 mm (females). Both sexes were mature at sizes considerably below the commercially acceptable size of 4 inches (102 mm) carapace width. After maturity, positive allometric growth was demonstrated for males. Females do not moult after reaching maturity. The small vasa deferentia found in soft-shelled mature males suggested that only hard-shelled males were capable of mating. A hard-shelled male successfully mated with a soft-shelled mature female. Field and laboratory observations suggest that more than one brood is commonly produced from one mating.The minimum size limit for commercial landings allows some mature males capable of mating to be left on the fishing grounds. Retention of this limit seems unlikely to affect the breeding potential of the population.

Density of the Commercial Spider Crab, Chionoecetes opilio, and Calibration of Effective Area Fished Per Trap Using Bottom Photography

1975 ◽  
Vol 32 (6) ◽  
pp. 761-768 ◽  
Author(s):  
R. J. Miller
Keyword(s):  
Carapace Width ◽  
Live Weight ◽  
Accurate Method ◽  
Effective Area ◽  
Mature Female ◽  
Spider Crab ◽  
Chionoecetes Opilio ◽  
Abundance Estimates ◽  
Crab Density ◽  
Fishing Area

Bottom photography was found to be a more accurate method of censusing the commercial spider crab, Chionoecetes opilio, than trawling or sight counting from a submersible. Because of their highly aggregated distributions, estimating abundance of mature female crabs and immature crabs of both sexes was not practical by any method. The larger males (≥ 40 mm carapace width), including those of commercial value, approached a random distribution, however; and abundance estimates for four study areas ranged from 5.2 to 9.2 crabs/500 m2 and from 2.2 to 4.2 kg live weight/500 m2. To permit results of exploratory fishing with traps to be converted to crab density and size of crab stocks available to a commercial fishery, a commercial crab trap was calibrated for "effective" area fished. The effective fishing area per trap averaged 4100 m2 over four study areas.

scholarly journals Morphometric and gonad maturity of the spider crab Libinia ferreirae Brito Capello, 1871 (Decapoda: Majoidea: Epialtidae) on the south-eastern Brazilian coast

2016 ◽  
Vol 97 (2) ◽  
pp. 289-295 ◽  
Author(s):  
Geslaine Rafaela Lemos Gonçalves ◽  
Eduardo Antonio Bolla Júnior ◽  
Maria Lucia Negreiros-Fransozo ◽  
Antonio Leão Castilho
Keyword(s):  
Vas Deferens ◽  
Ovigerous Female ◽  
Carapace Width ◽  
Gonad Development ◽  
Brazilian Coast ◽  
Spider Crab ◽  
Allometric Growth ◽  
Gonad Maturity ◽  
Gonadal Maturity ◽  
Gonad Condition

Sexual maturity of the spider crab Libinia ferreirae was assessed for each sex, based on body dimensions and observations of gonad condition. A total of 346 crabs were analysed, of which 68% were females. Immature and adult individuals were recognized based on their allometric growth and gonad development. Abdomen width (AW) vs carapace width (CW) and propodus length (PL) vs CW were the relationships that best separated allometric groups of females and males, respectively. For females, gonad and allometric morphological maturity were, respectively, 38.77 and 39.43 mm of CW, which is close to the carapace size of the smallest ovigerous female (38.08 mm). For males, gonad maturity was 34.86 mm of CW and three allometric phases were observed: immature (IM♂), adolescent (AD♂) and adult morphometrically mature (MM♂). The IM♂ phase showed lower values of CW and PL than the AD♂ phase, without spermatophores inside the vas deferens; the AD♂ phase exhibited higher CW values than IM♂, but lower CW and PL values than the MM♂ phase, and the presence of spermatophores in the vas deferens; the MM♂ phase had higher values of CW and PL than the AD♂ phase and spermatophores in the vas deferens. Therefore, females showed synchronic morphometric, gonadal and functional maturity, while in males, gonadal maturity was attained before morphometric maturity, which probably could be a reproductive strategy for this species.

Growth Per Molt and Limb Regeneration in the Spider Crab, Chionoecetes opilio

1976 ◽  
Vol 33 (7) ◽  
pp. 1644-1649 ◽  
Author(s):  
R. J. Miller ◽  
J. Watson
Keyword(s):  
Least Squares ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Limb Regeneration ◽  
Percentage Increase ◽  
Spider Crab ◽  
Chionoecetes Opilio ◽  
Size Growth ◽  
Zero Growth ◽  
The Difference

Spider crabs, Chionoecetes opilio, were held in the laboratory for observations on carapace width increments and limb regeneration per molt. The merus (the longest limb segment) of autotomized limbs regenerated to 48 and 73% of their full length, irrespective of crab size, on the first and second molt, respectively. Fitting least squares regressions to percentage increase of carapace width per molt (Y) vs. premolt carapace width (X [in millimeters]) gave the following equations: immature males Y = 40.7 − 0.363X; immature females Y = 45.3 − 0.444X; mature males Y = 14.2 + 0.051X; and females’ terminal molt to maturity Y = 14.0 − 0.014X. Only the slopes for the first two equations differed significantly from zero. Growth per molt decreased with sexual maturity for both sexes and was significantly less for females molting to maturity than for mature males of the same size. Growth per molt for immature females was significantly greater than for immature males, but the difference was slight.

Moulting and Mating of Snow Crabs, Chionoecetes opilio (O. Fabricius), in Shallow Waters of the Northwestern Gulf of Saint Lawrence

1992 ◽  
Vol 49 (7) ◽  
pp. 1282-1293 ◽  
Author(s):  
Bernard Sainte-Marie ◽  
François Hazel
Keyword(s):  
Carapace Width ◽  
Male Competition ◽  
Shallow Waters ◽  
Beam Trawl ◽  
Chionoecetes Opilio ◽  
Data Support ◽  
Mean Size ◽  
Males And Females ◽  
Gulf Of Saint Lawrence ◽  
Snow Crabs

Chionoecetes opilio in baie Sainte-Marguerite, Gulf of Saint Lawrence, were sampled by beam trawl in spring from 1988 to 1991 and by divers in March 1991 to document an hypothesized annual moult in shallow waters. Each spring, C. opilio occurred at 4–20 m of depth where 29.3–97.3% of males and 20.3–81.4% of females were moulting or recently moulted. Males and females [Formula: see text] carapace width (CW) moulted only on bottoms < 60 m. Females were mature at [Formula: see text] CW and males were morphometrically mature at [Formula: see text] CW. Overall, 0.3% of morphometrically mature (N = 575) and 23% of morphometrically immature (N = 826) males [Formula: see text] CW, exclusive of soft-shelled, had a visible second carapace. These and other data support the hypothesis of a terminal moult coincident with morphometric maturity. Pubescent females mated with males 59.9–109.3 mm CW (88% were < 95 mm CW), 97% of which were morphometrically mature (N = 120). Mean size of these males was greater than that of males grasping immature females or other males, indicating male competition for pubescent females. Morphometrically mature males were larger on bottoms > 80 m deep, where multiparous females concentrated, than on shallower bottoms.

scholarly journals Body Weight, Carapace Length and Width Relationship and Condition Factor of the Mud Crab Scylla serrata (Forskal) in Mangrove Ecosystem

2017 ◽  
Vol 9 (3) ◽  
pp. 338-343 ◽  
Author(s):  
Sarvabhowma Chakravarty MYLA ◽  
Vijaya Bharathi TIRUMANI ◽  
Rama Chandra Ganesh PATURI
Keyword(s):  
Carapace Length ◽  
Condition Factor ◽  
Carapace Width ◽  
Scylla Serrata ◽  
Regression Equations ◽  
Allometric Growth ◽  
Mud Crab ◽  
Relative Condition Factor ◽  
Males And Females ◽  
Relationship Of

The relationship of length-weight and width-weight of the carapace and the relative condition factor of mud crab Scylla serrata from Coringa Wildlife Sanctuary (Andhra Pradesh, India) was the subject of present study. Significant difference in both males and females was observed between carapace length-weight, carapace width-weight with a linear relationship. The regression values of both the sexes were found to be statistically significant. The regression equations calculated for length-weight were W= 0.00000178 L 3.1139 (r= 0.95) for males, W= 0.00000520 L 2.8056 (r=0.94) for females and for sexes combined it was W = 0.0000297 L 2.9891(r= 0.94).  In case of carapace width-weight relationship of males, females and sexes combined the regression equations were W= 0.00000121 CW 3.0426 (r= 0.92), W= 0.00000178 CW 2.775 (r=0.93) and W = 0.00000204 CW 2.9210(r= 0.92) respectively. The male crabs showed positive allometric growth whereas female had negative allometric growth. Analysis of covariance confirmed remarkable difference between males and females in the growth pattern. The mean relative condition factor (Kn values) of both males and females and of the pooled sexes ranged from 0.680 (April) to 1.029 (November). A gradual raise in Kn values was observed from small- to big- sized crabs in both the sexes. Peak values were observed in 12.0-13.9 cm size group in November.

scholarly journals Morphometric characteristics of crayfish, Cherax gherardiae, from Maybrat, West Papua, Indonesia

2018 ◽  
Vol 26 (4) ◽  
pp. 223-230
Author(s):  
Yulianus Sedik ◽  
Dominggus Rumahlatu ◽  
Bambang Irawan ◽  
Agoes Soegianto
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Carapace Length ◽  
Condition Factor ◽  
Carapace Width ◽  
Allometric Growth ◽  
Morphometric Characteristics ◽  
Significant Difference ◽  
West Papua ◽  
Males And Females

Abstract The objectives of this study were to determine the length-weight relationships (LWRs), chelae length (ChL)-width (ChW) relationships, carapace length (CL)-width (CW) relationships, sexual dimorphism, and condition factor (K) of Cherax gherardiae from Maybrat, West Papua Indonesia. The sex ratio of C. gherardiae was found to be 1.04:1. The LWRs for males, females, and all individuals were W = 0.225L1.96, W = 0.181L2.02, and W = 0.187L2.03, respectively. Males and females exhibited negative allometric growth (b<3). There was no significant difference in lengths between males and females; however, the weight of males was greater than that of females. The K values for males, females, and all individuals were 3.17, 3.09, and 3.13, respectively. The ChL of the crayfish ranged from 1.0 to 7.5 cm, and the ChW ranged from 0.4 to 2.5 cm. The CL of crayfish ranged from 1.6 to 6.0 cm, and the CW ranged from 0.6 to 4.1 cm. Males had longer chelae and carapaces than did females. There was no significant difference in chelae width or carapace width between males and females. The ChL-ChW relationships for males, females, and all individuals were ChW = 0.312ChL + 0.260, ChW = 0.397ChL - 0.050, and ChW = 0.345ChL + 0.119, respectively. The CL-CW relationships for males, females, and all individuals were CW = 0.750CL-0.955, CW = 0.526CL - 0.178, and CW = 0.635CL-0.543, respectively.

Grasping Behavior of Male Snow Crab Chionoecetes Opilio (O. Fabricius, 1788) (Decapoda, Majidae)

Crustaceana ◽  
1996 ◽  
Vol 69 (2) ◽  
pp. 211-222 ◽  
Author(s):  
Michel Comeau ◽  
Mikio Moriyasu
Keyword(s):  
Size Range ◽  
Wild Population ◽  
Carapace Width ◽  
Mature Female ◽  
Snow Crab ◽  
Second Phase ◽  
Chionoecetes Opilio ◽  
In The Wild ◽  
Solitary Males ◽  
Wide Size Range

AbstractThe grasping behavior of snow crab, Chionoecetes opilio, was observed in 43 males when only male crabs were collectively held in an aquarium. A larger male always grasped a smaller sized male which exhibited submissive behavior similar to a mature female in a mating pair. This grasping behavior was observed in terminal molt larger sized males except for one case observed for one intermolt juvenile male. During the mating season, although a wide size range of morphometrically mature males was present (51.0-131.0 mm in carapace width) in the wild population, mainly larger sized morphometrically mature males (72.1-128.4 mm in carapace width) participated in the mating courtship. A small number of solitary males was observed on the mating ground and their sizes were comparable to the males in mating pairs. Among the males in mating pairs, the larger sized males tend to occupy favorable mating grounds at greater depths, while the smaller sized males are found on less favorable grounds. The grasping behavior observed in the aquarium and in the wild suggests that the male-male grasping behavior appears to be related to the establishment of hierarchy among the mating males. Smaller sized morphometrically mature males appear to be eliminated before the mating pairs are formed and appear on the mating ground. On the mating ground, the second phase of competition among males occurs for favorable mating grounds.

scholarly journals Comparative analysis of the relative growth of Uca rapax (Smith) (Crustacea, Ocypodidae) from two mangroves in São Paulo, Brazil

2004 ◽  
Vol 21 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Daniela da Silva Castiglioni ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Comparative Analysis ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Reproductive Behaviour ◽  
Size At Maturity ◽  
Allometric Growth ◽  
Relative Growth ◽  
Males And Females ◽  
Two Populations ◽  
Major Cheliped

A study on the relative growth of two populations of Uca rapax (Smith, 1870) was performed primarily to determine the size at onset sexual maturity. The species was sampled monthly in Itamambuca (23º24'43"S and 45º00'73"W) and Ubatumirim (23º20'17.8"S and 44º53'2.2"W) mangroves. Carapace width (CW) and length (CL), abdomen width (AW), major cheliped propodus length (PL) and height (PH) for each sex, and gonopod length (GL) for males were measured with a calliper (0.01 mm). Allometric analyses were used to estimate size at maturity. The relationships that most precisely indicated the size at onset of sexual maturity were AW vs. CW, for females and PL vs. CW, for males. Males and females are mature, respectively at 15.2 and 12.1 mm CW in samples from Itamambuca and 13.5 and 11.2 mm CW in samples from Ubatumirim mangrove. Positive allometric growth of females abdominal width is likely related to the incubation process, while positively allometry growth of male's cheliped almost certainly relates to reproductive behaviour.

Morphometric and gonad maturity of the spider crab Libinia spinosa (Crustacea: Brachyura: Majoidea: Epialtidae) in Argentina

2010 ◽  
Vol 91 (4) ◽  
pp. 837-844 ◽  
Author(s):  
M.P. Sal Moyano ◽  
M.A. Gavio ◽  
M.D. Maggi
Keyword(s):  
Vas Deferens ◽  
Size Range ◽  
Carapace Width ◽  
Gonad Development ◽  
Principal Component ◽  
Spider Crab ◽  
Allometric Growth ◽  
Gonad Maturity ◽  
Morphometric Features ◽  
Different Types

Morphometric and gonad maturity of Libinia spinosa on the coast of Mar del Plata, Argentina, were assessed. In both sexes various morphometric features were measured to determine the morphometric maturity, and through macroscopic inspection of gonads and analysis of its content, different stages of gonad maturity were described and the physiological maturity was estimated. In females, the carapace width ranged from 8 to 56.5 mm while in males from 4.6 to 81.97 mm. The size at which 50% of females were morphometrically mature was calculated at 40.6 mm. Based on the allometric growth of the abdomen, two morphometric groups of females were recognized as juvenile and adult phases. In males, results of principal component analysis showed that the most suitable variables that efficiently represent the size and sexual differentiation factor were the carapace width and cheliped length respectively. The size at which 50% of males were morphometrically mature was estimated at 58.9 mm. Based on the allometry of the cheliped growth, two morphometric groups were recognized as immature and mature phases. Males maintained under laboratory conditions moulted and growth was related to regular and terminal moults. Males reached their terminal moult at a wide size-range, from 48.5 mm to 61.4 mm of carapace width. This terminal moult coincided with the size of morphometric maturity. In both sexes four stages of gonad development were described, two corresponded to immature phases and two to mature phases. The size at which 50% of females and males reached gonad maturity was LC50 = 40.33 mm and LC50 = 33.6 mm, respectively. In females, both morphometric and gonad maturity occurred at a similar size. In males, gonad maturity is acquired prior to morphometric maturity, thus three different types of males were characterized: (1) those with small carapace width and cheliped, without spermatophores in their vas deferens; (2) those with large carapace width and small cheliped, bearing spermatophores in their vas deferens; and (3) those with large carapace width and cheliped, bearing spermatophores in their vas deferens.

Effects of sexual dimorphism and body size on feeding behaviour of the fiddler crab, Uca bengali Crane, 1975

Crustaceana ◽  
2015 ◽  
Vol 88 (2) ◽  
pp. 231-242 ◽  
Author(s):  
F. W. Tina ◽  
M. Jaroensutasinee ◽  
K. Jaroensutasinee
Keyword(s):  
Body Size ◽  
Feeding Rate ◽  
Fiddler Crab ◽  
Carapace Width ◽  
Morphometric Measurements ◽  
Feeding Duration ◽  
Video Recordings ◽  
Large Size ◽  
Males And Females ◽  
Comparable Size

Uca bengaliCrane, 1975 females have two small feeding claws but males have one small feeding claw and another big claw used for waving and fights. On the basis of video recordings of feeding motions and duration, and morphometric measurements of body size (measured as carapace width) and feeding claw size (measured as dactyl length and width), differences in feeding rate per crab and per feeding claw, feeding duration, and feeding claw size between sexes were studied with the main aim to test male ability to compensate for the loss of one functional feeding claw. Additionally, feeding rate of males and females of small and large size classes was studied. Furthermore, correlations between feeding rate and body size, as well as feeding claw size and body size were investigated. Results showed that increased feeding rate per feeding claw coupled with a larger feeding claw allowed males to compensate for the loss of one feeding claw. Smaller males and females fed faster than larger ones. There was a negative correlation between feeding rate and carapace width. Feeding duration did not vary between males and females of comparable size. A positive correlation was observed between feeding claw size and carapace width.

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