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

Abstract

Specimens of Callinectes danae Smith 1869 were caught in northeastern Brazil (2178 males, 2031 females); of these, 24 males and 24 females were reared for 6 months. Water temperature (T) and salinity (S) showed a significant effect on the average ecdysis in wild crab (l), with a model obtained that was: l = exp(À0.12268T + 0.06148S)/(1 + exp(À0.12268T + 0.06148S)). Size at morphometric maturity was significantly larger for wild males and females (9.45 and 8.38 cm, respectively) than for reared individuals (8.95 and 7.93 cm). Females of sizes above CW 50 (carapace width at maturation) showed an increased ecdysis activity, whereas males showed a decrease in ecdysis frequency in sizes over CW 50 . Five and six molts were observed for females and males, respectively, in both wild and reared crabs; the modal classes of the reared crabs were shifted to smaller sizes. In reared females the terminal-pubertal molt occurred at 107 days of age and at 148 days, on average, in males. The intermolt period varied from 8 to 41 days and increased with age.U.S.

Effects of water temperature on growth, feeding and molting of juvenile Chinese mitten crab Eriocheir sinensis

“…feed conversion efficiency observed in this study were analyzed with standard methods of analysis of variance followed by LSD test for multiple comparisons. The number of days between two consecutive molts were accounted as inter-molt periods (IP), which was only registered after the second ecdysis, as it was not possible to determine the number of elapsed days prior to the last ecdysis before capture (Shinozaki-Mendes et al, 2014). Molt increment (MI, %) was recorded as the percentage weight and carapace width increase after a molting event:…”

Impact of unilateral eyestalk ablation on Callinectes arcuatus (Ordway, 1863) under laboratory conditions: behavioral evaluation

“…The eyestalk's ablation allows removing the neurohormones that inhibit early reproduction, gonadal maturation, and the decrease of the time needed to complete the molting cycle, which causes acceleration of these processes. In this sense, many of the functions such as reproduction, molting, feeding, growth, survival, efficiency in food conversion, metabolic processes, and behavior of the breeders, among others, can be affected, depending on the species and on the physiological state of the organism (Travis 1952, Sochasky et al 1973, Juinio-Meñez & Ruinata 1996, Mykles 2001, Shinozaki-Mendes et al 2013.…”

Presença do sistema melatoninégico e seu papel no ciclo de muda do siri-azul Callinectes sapidus (Crustacea Brachyura)

“…Os jovens, devido ao rápido crescimento, realizam mais mudas que os animais adultos. Há também uma diferença no padrão do ciclo de muda entre machos e fêmeas, uma vez que os machos precisam estar com a carapaça rígida para a cópula, ao contrário da fêmea que sofre a muda de maturação e, assim, fica com o corpo mole para receber os espermatóforos, ou seja, no momento da cópula os machos estarão em intermuda e as fêmeas em pós-muda (Shinozaki-Mendes et al, 2013). Após a muda da maturação, as fêmeas entram em estágio de anecdise, e o ciclo de muda é interrompido.…”