Histological characterization of the digestive tract of Hypostomus paparie (Fowler, 1941).
Histological analisys, digestive system, air-breathing, cascudo.
Hypostomus paparie is a fish belonging to the Siluriformes order and Loricariidae family, that inhabits regions with neotropical waters. Within the Neotropical region, there is a semiarid region, characterized by strong sunlight, high temperatures, scarce, irregular rainfall, and short periods of precipitation. Another particularity of semiarid waters is their anthropic use for leisure activities, fishing, agriculture, livestock, water supply for cities, and electricity production. These characteristics make its waters hypoxic. Throughout evolution, fish have developed adaptations to survive in this kind of environment, such as using part of their digestive system for facultative air-breathing. The objective of this work was to characterize the digestive system of H. paparie to contribute to research related to the physiology, ecology, and evolution understanding of this species. For the methodology, 10 specimens were used, collected in the Apodi-Mossoró river, a stretch where the Santa Cruz dam is located, in Apodi city. The collected animals were taken to the laboratory to undergo histological procedures. The analysis showed that H. paparie begins its digestion in the esophagus, with more intensity in the intestine. The stomach has a dual function, digestion, and respiration, with digestion most prominent in the cardiac region and respiration pyloric region. The anterior intestine part also has breathing work, in addition to digestion, the middle and posterior region is characterized by their digestive activity.