Digestive Enzymes in Larvae and Juveniles of Farmed Sharpsnout Seabream (Diplodus puntazzo) (Cetti, 1777)

Abstract

Abstract:The ontogenetic development and pattern of main digestive enzyme activities (proteases, carbohydrases and lipases) were investigated in farmed sharpsnout seabream Diplodus puntazzo larvae and juveniles, during the passage from the larval stage to adult (from 21 to 277 days after hatching -DAH). Larvae showed exponential growth, thus confirming that Rotifers and Artemia nauplii are suitable preys for early feeding of D. puntazzo larvae.Pepsin activity was low in the larvae, but it increased afterwards in relation with stomach development. In juveniles, levels of specific activity of trypsin, chymotrypsin and elastase were lower compared to that recorded in larvae. A decrease in the activity of the alkaline proteases could be related to an increase in the functionality of stomach. Qualitative and quantitative assay of glycosidases ( -amylase, cellulase and maltase) showed high glycosidase activity, indicating that D. puntazzo is capable of digesting carbohydrates in its diet. Levels of lipase activity in juveniles were higher than those found in larvae. Our results didn't show an inductive character of lipases, since in juveniles the activity levels were almost constant even if the fat content of compound diet varied (from 7.0 % to 20 %).The rapid changes in the digestive activities of D. puntazzo larvae supported the existence of well established induction and regulation digestive mechanisms. Present results also confirm that D. puntazzo larvae have complete digestive enzymatic equipment that increased during larval ontogeny and enable larvae to digest and absorb nutrients contained in live preys once exogenous feeding occurred. The enzymatic pattern is correlated with omnivorous feeding habits of the species. Moreover, the patterns of activity of the main digestive enzymes of D. puntazzo larvae and juveniles indicated the early functional development of their digestive system and suggested this species as a good candidate for Mediterranean aquaculture using the compound diet.

The Age Dependent Activities of Digestive Enzymes in Rasbora, Rasbora lateristriata Blkr., (Pisces: Cyprinidae)

“…In this study, the highest amylase activity was found at pH 6.9 and 8.1, but it decreased at pH 10.0. The results of this study are lower than in previous studies on fish Betta splendens and Diplodus puntazzo (Savona et al, 2011). High amylase activity at neutral to slightly alkaline pH, which reflects that the starch hydrolysis process occurs at a neutral to alkaline condition.…”

“…The activities of cellulose in the intestine of fish were also shown in previous studies on fish omnivore (Fagbenro et al, 2005;Tongsiri, Mang-Amphan & Peerapornpisal, 2010;Savona et al, 2011). However, previous studies showed that cellulose activity was related to the composition of the feed in the digestive tract.…”

“…The effect of age or size of the fish on the digestive enzyme activity has also been documented in previous studies (Klahan, Areechon, Yoonpundh, & Engkagul, 2009;Thongprajukaew, Kovitvadhi, Engkagul, & Rungruangsak-Torrissen, 2010;Susilo, Yuwono, Rachmawati, Priyanto, & Hana, 2015). However, the effect of age on enzyme activity changes when diet and feeding guilds differ (Day et al, 2011a;Savona et al, 2011;Pena et al, 2015). In spite of elaborate study on digestive enzyme on various fish species, no published data are available for Rasbora digestive enzyme activities related to its age.…”

“…Measurement cellulose activity used 3,5-Dinitrosalicylic acid (Sigma-Aldrich, AG) method with carboxymethylcellulose (CMC) as substrate (Savona et al, 2011). Reagent mixture consisted of a substrate (300 µL), 0.1 M sodium acetate buffer (300 µL) and enzyme extract (60 µL) were incubated for 10 minutes at 40 °C then the reaction was stopped by the addition of 900 µL of DNS 1% (w/v) reagent.…”

“…The activities of alkaline protease such as trypsin and chymotrypsin, have also been studied in a variety of fish (Kamarudin, Otoi, & Saad, 2011;Savona, Tramati, & Mazzola, 2011). These enzymes showed different activities in the fish digestive tract, according to feed quality (Debnath et al, 2007;Chaudhuri, Mukherjee, & Homechaudhuri, 2012;Abdel-Warith, Younis, & Abdualla, 2013), feeding guilds (Falcon-Hidalgo, Forrellat-Barrios, Farnes, & Hernandez, 2011;Langeland, Lindberg, & Lund, 2013), phylogeny (German, Horn, & Gawlicka, 2004;Kumar et al, 2007), and sex (Thongprajukaew & Kovitvadhi, 2013).…”