Moulting in the grow‐out of farmed shrimp: a review

Abstract

The importance of moulting for growth in farmed shrimp is reviewed in relation to the physiological cycle, induction triggers, behavioural and compositional changes, elements for successful moulting and potential strategies for moulting management. Successful ecdysis is also dependent on pond water quality, health and nutritional status. The stages in the moulting cycle are as follows: premoult, the preparation period for moulting that comprises the longest period in the cycle and includes accumulation of nutrient reserves; post-moult, short and crucial stage for shrimp recovery after moulting; and intermoult, when feeding is continuous and most of growth occurs. The ecdysis is very rapid and mainly dependent on suitable physiological status of individuals. Up to 10% of the whole shrimp moulting cycle may rely on body nutrient reserves, once feeding is decreased or ceased (premoult and post-moult). Moulting is started by hormonal increments in haemolymph, 20-hydroxyecdysone and methyl farnesoate, which are found similar in insects. Beyond health and nutrition, proper environmental conditions such as good water quality are essential for successful moulting, hardening of exoskeleton and rapid growth. Moulting prediction and management may result in significant feed savings in pond farming and potential effects of, for example, moon phases and stressors have to be further considered. The complex nature of moulting in shrimp, including different sorts of endocrine regulation and environmental stimuli, suggests it is difficult to be precisely controlled in farmed populations. Moulting physiology of shrimp is discussed in relation to some farming practices.

Practical application of sea urchin shell flour supplementation as a stimulant moulting in vannamei shrimp

“…Similarly, the pond's distance from the coast leads to a higher reduction in salinity. In low salinity ponds, shrimp have difficulty maintaining mineral balance, and this tends to result in mortality during moulting (Lemos and Weissman, 2021). Within these conditions, calcium addition through feed is a practical application to supply the shrimp's calcium needs.…”

“…Supplementations in feed used egg whites as a binder, but leaching seemed to occur in this study, as indicated by the water color becoming more turbid in the calcium supplemented treatments. However, leaching calcium is likely absorbed by L. vannamei through the osmotic mechanism (Li and Cheng, 2012;Lemos and Weissman, 2021). Table 3 shows leaching calcium absorption indication is the water's narrow pH range.…”

“…Moulting performance at doses of 2 and 6 g, is the calcium supply's impact in both doses. At a 2 g dose, the calcium supply is considered insufficient, thus, moulting performance is inoptimal because the shell formed is thinner, old shell separation and new shell hardening durations are longer, and energy is widely used to maintain the balance between calcium in the body and water (Li and Cheng, 2012;Tavabe et al, 2013;Jannathulla et al, 2020;Lemos and Weissman, 2021). Conversely, calcium supply at a 6 g dose is considered excessive, thus, there is a deposition of minerals in the shell with the capacity to delay moulting (Jaganmohan and Kumari, 2018).…”

“…Moulting is an important event in the physiology of crustaceans (Chang, 1995;Corteel et al, 2012;Lemos and Weissman, 2021), and is characterized by 4 phases, including pre-molt, molt, post-molt, and inter-molt (Merrick, 1993;Chang, 1995;Corteel et al, 2012). Furthermore, calcium and magnesium are required to support the activities in each phase, due to the importance in shell hardening (Tavabe et al, 2013;Nurussalam et al, 2017;Lemos and Weissman, 2021).…”

“…Moulting is an important event in the physiology of crustaceans (Chang, 1995;Corteel et al, 2012;Lemos and Weissman, 2021), and is characterized by 4 phases, including pre-molt, molt, post-molt, and inter-molt (Merrick, 1993;Chang, 1995;Corteel et al, 2012). Furthermore, calcium and magnesium are required to support the activities in each phase, due to the importance in shell hardening (Tavabe et al, 2013;Nurussalam et al, 2017;Lemos and Weissman, 2021). Moreover, both tend to also play a role in physiological homeostasis, osmoregulation nerve transmission, muscle contraction, protein Depik Jurnal Ilmu-Ilmu Perairan, Pesisir dan Perikanan Volume 10, Number 2, Page 107-114 Heriansah et al (2021) synthesis for growth, and as cofactors in metabolic processes (Li and Cheng, 2012;Jannathulla et al, 2020).…”