Age and growth of Callinectes danae (Brachyura: Portunidae) in a tropical region

Abstract

we reared 24 males and 24 females for 6 months. The relative growth (relation between weight and cephalothorax width) showed negative allometry, except in adult males. The females presented marked changes in relative size of the fifth pleomere as they matured, while the males showed changes in chela size. As rearing progressed, the females underwent ecdysis five times while the males underwent ecdysis six times. The puberal molt was the last to occur. The von Bertalanffy growth model (with t 0 ) provided the best fit, when compared to the von Bertalanffy (with CW 0 ), von Bertalanffy (with t 0 = 0), Gompertz, and Richard models. The following growth functions for reared individuals were obtained: CW t = 9.88(1−exp(−0.0228(t+14.27))) and CW t = 8.02(1−exp(−0.0158(t+26.23))). For wild individuals the growth functions were as follows: CW t = 12.12(1 − exp(−0.0052(t + 29.36))) and CW t = 9.48(1 − exp(−0.0036(t + 59.04))), for males and females, respectively. The individuals reached smaller sizes in the rearing system; however, the growth rate was higher. The mean longevity ranged from 375 to 429 days for males and from 458 to 553 for females. The maximum longevity ranged from 550 to 860 and from 764 to 1205 days, for males and females, respectively.

Ontogenetic trajectories in Callinectes danae (Crustacea: Brachyura): sex and age polymorphism

“…Among the studies using linear morphometrics of C. danae , Furia et al (2008) in North-eastern Brazil examined the relationship between the width and length of the cephalothorax for individuals from 4.3 to 12.5 cm for the different sexes. For the same population studied here, Shinozaki-Mendes et al (2012b) separated males from females and juveniles from adults showing relationships between cephalothorax width and both abdomen width and chela length. While all of these relationships were significantly different, the classification ‘juvenile’ included the female stages 1–5 and the male stages 1–6 as defined here.…”

“…Our research utilized the age groups (instars) proposed by Shinozaki-Mendes et al (2012b) for males (seven instars) and females (six instars) (Table 1). These values were obtained using the Bhattacharya method (Gayanilo et al , 2005) and were validated by performing experimental cultivation, as cited in this paper.…”

First record and preliminary information on the biology of the deep sea African crab, Chaceon gordonae (Ingle, 1985) (Brachyura: Geryonidae) in Saint Peter and Saint Paul Archipelago, Brazil

“…The inflexion point on the curve, indicating the occurrence of a significant change in the previous growth pattern, in which the pubertal molt probably occurs, was determined by the maximum difference in intercept (β0) and angular coefficients (β1) of the models (FontelesFilho, 2011;Shinozaki-Mendes et al, 2012a), in which consecutive values of CL are used as separation points between immature and mature curves, and the highest value is considered the point of maximum inflection. For comparison between coefficients (β0 and β1) of the models, the "W" test was used, which is based on maxi-mum likelihood and uses the chi-squared distribution (Mendes, 1999;Shinozaki-Mendes et al, 2012b). Regenerating chela of males were excluded from the analysis.…”

Comparative study of the molting cycle of wild and reared swimming crabs Callinectes danae (Crustacea: Portunidae)

“…To determine the size in which the average pubertal molt occurs – a size at which 50% of the individuals are found capable of reproducing (CW 50 ) – the relative frequency of adults in each cephalothorax width class (CW) was used in the logistic model: Mf = 1/(1 + exp(β 0 + β 1 CW)) (Mendes, ), in which Mf is the percentage of the individuals able to reproduce. The W‐test (Mendes, ; Shinozaki‐Mendes et al., ) was used to compare the parameters of the logistic model.…”