Ontogeny of pancreatic enzymes in larval red drumSciaenops ocellatus

Abstract

The growth, survival and trypsin, lipase and amylase activities of red drum larvae were measured in two experiments. For the first trial, a group was fed live prey only (L) and another group was fed a combination of a microparticulate diet (MPD) and live food (L‐MP). For the second growth trial a group fed the MPD only (MP) and a starvation group (ST) were examined in addition to the L and L‐MP treatments. Enzyme activities of live prey were measured to estimate their possible contribution to larval digestion. No significant (P > 0.05) differences in final size and survival were observed between treatments L and L‐MP. Larvae subjected to starvation or fed the MPD diet alone were smaller than treatments fed live prey and did not survive past days 5 and 14, respectively. Trypsin, lipase and amylase activities were detectable at hatching. No significant differences (P > 0.05) in total enzyme activities among treatments were observed before day 14. Specific activity of trypsin, lipase and amylase peaked on day 3 (prior to first feeding) and subsequently decreased. For trypsin, the percentage of enzyme activity potentially attributable to ingested prey increased with age to a maximum of 17%. For lipase and amylase this fraction was less than 5% throughout the study, except on day 8 (12% and 24%, respectively). The lack of significant differences observed in the activity of digestive enzymes among treatments suggests that dietary regime, availability of prey and possible effects of exogenous enzymes did not significantly influence enzyme activity. Therefore, the lower growth rate observed in the L‐MP, MP and starved treatments cannot be attributed to low digestive enzyme production of the enzymes measured. It is more likely that the MPD failed to supply the required nutrients for adequate development.

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“…Also, similar profile for amylase was recorded by Gisbert et al (2009) that they reported similarly two peak steps which have been measured firstly around 2 DAH concurrently with hatching and starting of exogenous feeding and also secondly after 25 DAH for this species . Additionally, these information were parallel with results obtained from D. labrax (Zambonino Infante and Cahu, 1994), S. ocellatus (Lazo et al, 2000), large yellow croaker, Pseudosciaena crocea, (Ma et al, 2005), and P. erythrinus (Suzer et al, 2006b) larvae. Additionally, Pérez-Jiménez et al estimated that dietary carbohydrate content seems to induce changes in protease, amylase and lipase activity even though the authors conducted feeding experiments in juvenile of Dentex dentex at 91.7±1.4 g mean mass (Pérez-Jiménez et al, 2009).…”

“…As observed for trypsin, chymotrypsin was first detected in preflexion stage on day 3 (concurrently with mouth opening) and its specific activity strongly correlated with tryptic activity of D. dentex larvae. Besides, chymotrypsin was first detected concurrently with trypsin at the day of mouth opening in the cultured marine fish S. aurata after 3 DAH (Moyano et al, 1996), P. eryhtrinus after 3 DAH (Suzer et al, 2006b), P. pagrus after 3 DAH (Suzer et al, 2007a), S. senegalensis after 2 DAH (Martinez et al, 1999), S. ocellatus after 3 DAH (Lazo et al, 2000), and D. labrax after 5 DAH (Zambonino Infante and Cahu, 1994). However, similarly to trypsin, chymotryptic activity exponentially increased by larval size and age during the first month and then gradually decreased until end of the study.…”

“…trypsin, pepsin) could be accepted as comparative deterministic tool as well as a predictor not only for description of nutritional capabilities but also quality indicators of marine fish larvae during early ontogeny (Ribeiro et al, 1999;Lazo et al, 2000;Cara et al, 2003;Suzer et al, 2006bSuzer et al, , 2007aSuzer et al, ,b, 2013Ribeiro et al, 2008;Gisbert et al, 2009). Besides, knowledge about larval nutritional status and also ontogenetical changes of digestive enzymes in larvae of new candidate species will be supplied the development of processes of food digestion and assimilation.…”

“…During the last two decades, numerous studies have shown that early ontogeny of the digestive enzymes could be evaluated as effective tool for determination of larval quality, performance and nutritional status and physiological response for preferred diet during both larval and weaning stage under culture conditions (Ribeiro et al, 1999;Lazo et al, 2000;Cara et al, 2003;Suzer et al, 2006b;Suzer et al, 2007a,b;Ribeiro et al, 2008;Gisbert et al, 2009;Suzer et al, 2013). Moreover, there are some studies related with D. dentex focused on larval development (Rueda and Martínez, 2001), histological ontogeny of the digestive tract (Santamaría et al, 2004), early life history (Fırat et al, 2005), and different culture techniques (Suzer et al, 2006a) of D. dentex however, some detailed investigations about digestive enzymes were conducted by SDS-PAGE (Alarcón et al, 1998) and spectrophotometric ) methods and also effects of different dietary formulations (Pérez-Jiménez et al, 2009) in this species under culture conditions.…”

Effects of dietary lipid levels on growth, survival and lipid metabolism during early ontogeny of Pelteobagrus vachelli larvae

“…Daily mortalities of darkbarbel catfish larvae (daily dead larvae/initial number of larvae, mean per treatment) during development. red drum (Lazo et al, 2000), while at 2 DAH (first feeding) in the brush border and cytoplasm of enterocytes of Senegalese sole (Ribeiro et al, 1999). The presence of enzymatic capacity before first feeding suggests that these enzymes were induced by genetic control, not by food intake.…”