Thermal tolerance of purple mud crab, Scylla tranquebarica (Fabricius, 1798), during egg incubation, larval rearing and juveniles’ production

Abstract

Interest in the production of crustacean aquaculture has focussed primarily on mud crab species; however, mud crab production still relies on wild‐caught juveniles due to the low production of viable seeds of mud crab. Thus, the aim of this study was to enhance mass propagation of purple mud crab seed by studying the relation of temperature on growth performance of the early life stage of purple mud crab. Several data such as survival, incubation duration and morphometric measurements were evaluated after temperature was exposed on the egg, larval and crablet stages. For the egg stage, high hatching success (78.95% and 75.00%) was noted within a limited temperature range (28°C and 30°C respectively). Also, significant increment of final egg diameter (0.33 ± 0.05 mm) after the berried crab incubated at 30℃. For larval stage, the highest survival rate was found when the larvae were reared at 30℃ and 31°C with 68.79 ± 2.69 and 66.98 ± 2.63% respectively. The largest morphometric measurements for megalopa (CW: 2.80 ± 0.15 mm) and C1 (CW: 2.86 ± 0.12 mm) were observed at 31℃. The yielded total juvenile at the end of the larval experiment indicated the highest production was obtained for temperature 31°C (1,095 ± 47.3 individuals) followed by 30°C (1,002 ± 84.7 individuals). For the crablet stage, the crablets were able to survive in a wide range of temperatures (26°C–32°C) with >95% survival; however, the temperature 26℃–29°C indicated larger morphometric measurements (CW: 6.24–6.39 mm). In brief, the optimal temperature for egg, larval and crablet stages was recommended within 28℃–30℃, 30℃–31℃ and 26℃–29℃ respectively.

Morphological, Histological, and Physiological Responses of Female Orange Mud Crab, Scylla olivacea (Herbst, 1796), Fed with Different Dietary Lipid Levels

“…At present, extensive studies have been conducted to observe the effects of external factors such as salinity, temperature, and photoperiod on hormonal influence during vitellogenesis and embryonic development [14][15][16]. However, very few studies have evaluated the effect of diets on the endocrine system, which directly influences reproduction in crabs [17].…”

Effect of temperature on sex and steroid hormones of purple mud crab, Scylla tranquebarica (Fabricius, 1798) during egg incubation, larvae rearing and juvenile production

“…Heat treatment was applied to eggs, larvae, and crablets to observe the effect on sex ratio and steroid hormones. Previous works indicated the viable temperature for egg, larval and crablet stages were recommended within 28°C–30°C, 29°C–32°C and 26°C–32°C respectively (Hidir, Aaqillah‐Amr, Azra, et al, 2021). Based on these results of previous thermal tolerance experiments, the present work designed different temperature incubation for the egg (28°C and 30°C), larvae (28°C, 30°C and 32°C), and juveniles (26°C, 28°C and 30°C) for sex percentage experiments.…”

“…The difference between males and females was determined through gonopod, gonopore, and abdominal flap, according to Hidir et al (2021,b). The sex percentage was calculated by dividing the total male or female juveniles per total juveniles and multiplying by 100.…”