Composition of gastrointestinal content, protease and lipase activities in summer and winter of four freshwater siluriforms (Teleostei: Actinopterygii) with two different feeding habits

• Published in: Zoologia (Curitiba, Brazil) Brazil), 2018-01, Vol.35, p.1-8
• Main Authors: Gottlieb Almeida, Ana Paula, Zardo, Everton Luis, Toni, Candida, Behr, Everton Rodolfo, Picolli da Silva, Leila, Vieira, João Paes, Loro, Vania Lúcia, Baldisserotto, Bernardo
• Format: Article
• Language: English
• Subjects: Adaptation; Anus; Aquaculture; Biology; Body composition; Catfish; Chymotrypsin; Composition; Diet; Digestive enzymes; Enzymatic activity; Enzyme activity; Enzymes; Feeding; Fish; Food; Food composition; Foods; Freshwater; Gastrointestinal system; Gastrointestinal tract; Habits; Homogenization; Inland water environment; Lipase; Lipids; Mineral nutrients; Morphology; Nutrient availability; Nutrients; Pepsin; Physiology; Protease; Proteinase; Proteins; Sediments; Species; Stomach; Summer; Trypsin; Winter; ZOOLOGY
• ISSN: 1984-4689; 1984-4670; 1984-4689
• DOI: 10.3897/zoologia.35.e13286

The aim of this study was to determine the composition of gastrointestinal content and protease and lipase activities in summer and winter as well as to evaluate the relationship between digestive enzyme activity and centesimal composition of gastrointestinal content and feeding habits of two omnivorous species, Rhamdiaquelen (Quoy & Gaimard, 1824) and Pimelodusmaculatus (LaCèpede, 1803), and of two detritivorous species, Loricariichthysanus (Valenciennes, 1835) and Hypostomuscommersoni (Valenciennes, 1836). The activities of pepsin, trypsin, chymotrypsin, and lipase, and the levels of proteins and lipids in the gastrointestinal tract, were evaluated. The enzyme activities were not related to the centesimal composition of gastrointestinal content or feeding habits. This finding could be associated with the variations of nutrient availability over time in the environment, as was observed in the centesimal composition of food ingested by the fish in summer and winter. The analyzed enzymes exhibited a constitutive character in these species; that is, the digestive enzymes are always available in the gastrointestinal tract to digest any food that the fish may find as an adaptation to better utilize the nutrients available in the environment in winter and summer.