Enzymatic Activity in the Gastrointestinal Tract of Pimelodus maculatus (Teleostei, Siluriformes) in Two Neotropical Reservoirs with Different Trophic Conditions

Abstract

Enzymatic activities for digestion of proteins and carbohydrates were compared among three organs of the digestive system of Pimelodus maculatus in two reservoirs with different trophic conditions during the winter of 2006. The aim was to test the hypothesis that enzymatic activity for the digestion of proteins and carbohydrates differed among organs and that such activities differ between the trophic state of the environment. Enzymatic activities were determined through the assays of specificity for trypsin, chymotrypsin and β-glucosidase enzymes. The intestine had higher trypsin-like enzymatic activities compared to the stomach and liver. The highest β-glucosidase activity was found in the liver compared to the stomach and intestine in the oligotrophic reservoir only. Overall, enzymatic activity did not differ between the eutrophic and oligotrophic reservoirs, although the intestinal chymotrypsin was comparatively higher in the eutrophic reservoir and the hepatic β-glucosidase was higher in the oligotrophicreservoir. These findings indicated that most digestive activity occurred in the intestine for P. maculatus, which was probably related to its omnivorous/carnivorous feeding habits. The highest proteolytic activity in the intestine was expected for most fishes, but the high hepatic β-glucosidase in the oligotrophic reservoir was unexpected. The hepatic β-glucosidase as well as the intestinal chymotrypsin-like activity could be considered as the candidates for biomarkers of environmental quality.

Expression analyses of digestive enzymes during early development and in adults of the chame fishDormitator latifrons

“…On the other hand, in the long‐whiskered Pimelodus maculatus was reported a hepatic β‐glucosidase activity higher in an oligotrophic reservoir, while the chymotrypsin‐like activity was higher in eutrophic reservoir. These results could be related to the microbiota activity in the intestinal tract, as a result of the food habits and the environment, (Duarte, Bemquerer, & Araújo, ). In some species, it has been found that the morphology of the digestive tract and the digestive enzyme activity are related to the feeding habits during their ontogeny as in the characid fish Brycon guatemalensis (Drewe, Horn, Dickson, & Gawlicka, ) and that the structure of the digestive tract can be adapted to the diet as catfish Pachypterus khavalchor (Gosavi, Chandani, Sanjay, Manoj, & Kumkar, ).…”

Histopathological analysis of liver of the catfish <i>Pimelodus maculatus</i> in a tropical eutrophic reservoir from Southeastern Brazil

“…As a result, the Funil Reservoir has experienced large eutrophication in recent decades, resulting in frequent and intense cyanobacterial blooms (Branco et al, 2002;Rocha, Branco, Sampaio, Gomara, & Filippo, 2002;Rangel, Silva, Rosa, Roland, & Huszar, 2012;Pacheco et al, 2017). Despite this situation, the reservoir supports a rich fish community (Duarte, Bemquerer, & Araújo, 2015). Among the fish species, the long-whiskered catfish Pimelodus maculatus Lacepède, 1803, is one of the most abundant and widely distributed fish that are found not only in this reservoir, but also through the entire Paraiba do Sul River extent (Araújo, Pinto, & Teixeira, 2009).…”

Red Cusk-Eel (Genypterus chilensis) Gut Microbiota Description of Wild and Aquaculture Specimens

“…In the intestinal content samples from wild red cusk-eel, the enzymatic activities α-Glucosidase, β-Glucuronidase and β-Galactosidase are determined mainly by carbohydrate present in the diet [42]. The activities α-Fucosidase and N-Acetyl-β-glucosaminidase in the gastrointestinal tract have been related to host-microbiota interaction, affecting the microbial community composition [43], besides N-Acetyl-β-glucosaminidase, may be related to chitin biodegradation, an important component of crustaceans (Figure S3), which are the main source of food for the wild red cusk-eel that inhabits the rocky bottoms of the continental shelf at a depth of 20-150 m and use caves for sheltering and haunting [7,44,45].…”