Intestinal morphometry and cell density features in tropical farmed fish: A methodological approach

Abstract

Technological advances in genetic improvement, management, health and nutrition have allowed aquaculture activities to attain high levels regarding animal protein, production, and commercialization.The annual growth of this sector and the nutritional quality of meat are factors that make fish increasingly desirable for consumers. Brazil has emerged as a promising global supplier of aquaculture products due to the growing number of high-tech farms and productivity, particularly in the provision of native fish species (Valentin et al., 2021).Several species of fish play an important role in the economies of many countries worldwide. Many of these species are native and regionally adapted but are raised on fish farms and subjected to adaptive conditioning techniques because of their commercial value.In recent years, global production has experienced substantial advances in productivity methods for human consumption of farmed fish (FAO, 2020). Commercialization success is fundamentally based on dietary strategies for growth and weight gain from several formulated and commercially available fish feeds (Li & Robinson, 2015).However, these artificial feed formulations mainly target protein

Linking anatomical and histological traits of the digestive tract to resource consumption and assimilation of omnivorous tetra fishes

“…However, exceptions exist, such as in Leporinus species and farmed species, where a greater abundance of goblet cells was noted in the anterior intestine, potentially linked to neutralizing stomach acids (Albrecht et al, 2001;Bellinate et al, 2023). In contrast, Salmo salar showed no significant differences in goblet cell abundance between intestinal segments (Løkka et al, 2013).…”

“…This distribution pattern aligns with observations in various species across different genera, where a higher abundance of goblet cells in the posterior region is often associated with the process of defecation (Cho et al., 2023; Faccioli et al., 2014; Germano et al., 2014; Matheus et al., 2021; Rincón et al., 2023). However, exceptions exist, such as in Leporinus species and farmed species, where a greater abundance of goblet cells was noted in the anterior intestine, potentially linked to neutralizing stomach acids (Albrecht et al., 2001; Bellinate et al., 2023). In contrast, Salmo salar showed no significant differences in goblet cell abundance between intestinal segments (Løkka et al., 2013).…”

“…The J‐shaped stomach is typical of carnivorous and omnivorous fish and enables efficient digestion of large prey, while the U‐shaped stomach of herbivorous fish allows for prolonged processing of plant matter, reflecting their respective feeding behaviors (Gerking, 1994). Observed abundant neutral mucins at the apical surface of the epithelial cells are serving a protective role against autodigestion processes induced by acidic secretions from gastric glands (Bellinate et al., 2023; Cao & Wang, 2009; Faccioli et al., 2014). Gastric glands were present in the cardiac and fundic regions, playing a crucial role in prey digestion (Albrecht et al., 2001; Cao & Wang, 2009; Faccioli et al., 2014).…”

“…Following the methodology outlined by Bellinate et al. (2023) and Curvo et al. (2020), we used histological photographs and Fiji‐ImageJ software (Schindelin et al., 2012) to determine the number of goblet cells, thickness of the muscle layer, and the perimeter and area of the lumen, as a proxy for the absorption surface.…”

“…For a quantitative examination of the digestive tract traits, we took three histological photographs of each segment from five individuals per species. Following the methodology outlined by Bellinate et al (2023) and Curvo et al (2020), we used histological photographs and Fiji-ImageJ software (Schindelin et al, 2012) to determine the number of goblet cells, thickness of the muscle layer, and the perimeter and area of the lumen, as a proxy for the absorption surface. We analyzed these variables only for the esophagus and intestine segments, as the degree of stomach fullness (i.e., full vs. empty) could cause measurement bias.…”