Ontogenic Development of Digestive Enzymes of Mud Crab (Scylla paramamosain) During Larval Stages

Influence of Live-Food (Brachionus rotundiformis) Density at First-Feeding on Digestive Enzyme Activities in Newly Hatched (Zoea I) Larvae of the Mud Crab, Scylla serrata

“…Analyzing the activities of enzymes critical to digestion is a relatively novel approach to evaluate the suitability of food densities for larval crustaceans (Genodepa et al 2022a). Although enzyme activity patterns are known to vary throughout onto-genesis in mud crabs (Tang et al 1995, Serrano & Traifalgar 2012, Khoa et al 2019), this study confirmed they also vary in response to food densities within 24 h from first-feeding. Similar observations have been made for other larval crustaceans, such as the tropical spiny lobster Panulirus ornatus (Genodepa et al 2022a, 2022b, 2023).…”

“…In recent decades, progress has been made toward identifying suitable foods and appropriate feeding protocols (Quinitio et al 1999, Zeng & Li 1999, Li & Zeng 2001, Suprayudi et al 2002, Jantrarotai et al 2004, Ruscoe et al 2004, Davis et al 2005, Maheswarudu et al 2007, Baylon 2009, Serrano & Traifalgar 2012, Cruz-Huervana et al 2022), but improved targeting of diets to match the digestive physiology of larvae remains a major research focus (Holme et al 2009, Waiho et al 2018. Compared with later zoeal stages (Zoea IV-V) of mud crabs, which can accept a wide range of food types of varying particle size (Genodepa et al 2004a, Holme et al 2006, the first zoeal stage has a rudimentary feeding apparatus and alimentary tract (Li & Li 1998, Jantrarotai et al 2005, Lumasag et al 2007) that greatly limits ingestive (Genodepa et al 2004b, Maheswarudu et al 2007 and digestive (Tang et al 1995, Serrano 2012, Serrano & Traifalgar 2012, Khoa et al 2019 capabilities. This presents a significant feeding challenge for hatchery production of mud crabs because access to suitable foods from the onset of feeding (i.e., "first-feeding") is critical to maximize survival and growth (Li & Zeng 2001.…”

Optimal Dietary Protein Requirement for Juvenile Sesarmid Crab (Episesarma singaporense)

“…Some nutritional changes were observed through the activities of all the protein-digesting enzymes, except for chymotrypsin, suggesting the modulation of protein catabolism due to different dietary protein levels. The presence of pepsin-like activity has been reported in adult lobsters and crabs [ 35 , 36 ], as well as in the early developmental stages of E. singaporense crab [ 21 ], spider crab [ 23 ], and mud crab, Scylla paramamosain [ 37 ]. The highest specific activity in crabs receiving 35% protein might be due to the relatively high amount of preferably aromatic amino acids in their diet, such as phenylalanine, tryptophan, and tyrosine, which are most efficient in cleaving peptide bonds [ 38 ].…”