Moult induction methods in soft‐shell crab production

Abstract

Soft‐shell crabs are gaining attention internationally as a more lucrative option of selling commercially important portunid species due to their ease of consumption, high nutritional values, and unique and excellent taste. This product, however, is only attainable in captivity as crabs are harvested right after moulting when their exoskeletons are still soft. Among the most crucial factor in soft‐shell crab production is the moult induction method. Shorter moult intervals imply more soft‐shell crabs could be produced, increasing productivity and profit for farmers. This review describes the moulting event, soft‐shell crab production process and production systems, and highlights the currently available and potential moult induction methods, including eyestalk ablation, limb autotomy, the use of ecdysteroid, phytoecdysteroid, biogenic amines and methyl farnesoate, the inhibition of moult‐inhibiting hormone (MIH) and the regulation of physical parameters. This review further compares these moult induction methods and their benefits towards soft‐shell crab production.

Ecdysteroids

“…A similar approach has been suggested for the synchronisation of development in prawns and reduction of the moulting period [97,98] and in the generation of soft-shelled crabs for the commercial market [99].…”

Utilization of Feed and Growth Performance of Mud Crabs: The Effect of Herbal Extracts as Functional Feed Additives

“…As the growth of crab weight was not always followed by the growth of the width or length of the carapace, the growth indicator using the condition factor value was significantly helpful. In portunid crabs, the molting process is divided into four main stages, namely intermolt, premolt, ecdysis and postmolt (Waiho et al, 2021). The intermolt is the stage after cuticle formation, and the exoskeleton has hardened after mineralization has fully occurred.…”

“…Prices are also influenced by the shape of the product such as soft-shell crab (Fujaya et al, 2020). Waiho et al (2021) stated that soft-shell crab products are one of the crab culture products with world market demand that continues to increase at high prices. Currently, there are three different culture systems including crab fattening, grow-out, and soft-shell crab production in practice that target different tiers of the global crab market (Rahman et al 2020).…”

“…Molting is a precursor to growth and vice-versa. Therefore, various efforts have been made to stimulate growth and molting in crab culture, such as limb autotomy, eyestalk ablation, ecdysteroid and phytoecdysteroid application, control of physical parameters such as temperature and salinity, biogenic amines application, methyl farnesoate application, and molt-inhibiting hormone (MIH) inhibition (Waiho et al, 2021).…”

Transcriptomics in advancing portunid aquaculture: A systematic review

“…Moulting is a prerequisite for the growth of crustaceans. In general, the cyclic moulting process is divided into premoult, intermoult, moult, and postmoult stages and is stimulated by ecdysteroids but suppressed by moult‐inhibiting hormone (MIH) and CHH 63 . The former is synthesised by Y‐organs and the latter by neurosecretory cells of the X‐organ/sinus gland (XO‐SG) complex located in the eyestalks 64 .…”