&lt;b&gt;Morphological and anatomical characterization of the digestive tract of Centropomus parallelus and &lt;i&gt;Centropomus undecimalis&lt;/i&gt;&lt;/b&gt; - doi: 10.4025/actascibiolsci.v35i4.14352

Márcia Regina Fragoso Machado,Helena De Oliveira Souza,Alexandre De Azevedo,Valderes Lemos De Souza,Roberto Goitein,André Dias Nobre

doi:10.4025/actascibiolsci.v35i4.14352

Abstract

Centropomus parallelus and C. undecimalis are the most common species of Centropomidae in Brazil. Some authors attribute their failure to grow under in artificial conditions due to limited knowledge on the morphological and functional development of their digestive system and on nutrition requirements of both species. Current research characterizes histologically and histochemically the digestive tract of C. parallelus and C. undecimalis to provide a histophysiological assessment for studies related to their nutritional needs. In the esophagus, the mucous cells in the epithelium stained positively for PAS and AB. In the stomach, positive reactions to PAS and negative to AB respectively occurred on surface and mucous cells in the epithelium and in the lamina propria. In the intestine, goblet cells showed ratio similarity, with mucus being positive in AB and PAS. A greater concentration of these cells existed in the middle and distal intestine, with a greater increase of secretions when compared to those in the proximal intestine. Results show that C. parallelus and C.undecimalis display the main features of the digestive tract of carnivorous fish, a well-developed stomach and a relatively short intestine. In fact, they give insights for future studies on the mechanisms related to the species's digestive and absorptive physiology.

Highlights

Centropomus parallelus and C. undecimalis are euryhaline fish species and are defined as carnivores
The farmed specimens were captured at the Polo Regional Vale do Ribeira of the Agencia Paulista Tecnologia Agronegocios (APTA), Pariquera-Açu, Brazil (24o43’S; 47o53”W) and at the Laboratory of Marine Fish Culture (Lapmar), Universidade Federal de Santa Catarina (UFSC), Florianópolis, Santa Catarina State, Brazil (27o36’S; 48o37”W)
The intestine was short and rolled into the abdominal cavity, forming three segments, namely: the proximal intestine, which was connected to the pyloric caecum, and the medial and distal intestine which formed the final part of the last segment, ending in a sphincter (Figure 1)

Summary

Introduction

Centropomus parallelus and C. undecimalis are euryhaline fish species and are defined as carnivores (they feed on fish, shrimp and small crustaceans during the juvenile stage). When juvenile and adults fish of these species are bred in confinement, they become highly resistant to handling procedures and changes in physical-chemical parameters of water (CERQUEIRA et al, 2005) and their feed consumption improves. The snook is a genus with acknowledged ecological importance and high economic potential for fishing, aquaculture and sports. Their meat presents high organoleptic quality and a high market value (CERQUEIRA, 2005). Due to their high commercial value, the species have been captured intensely and a decrease of stocks occurred in natural environments (ALIAUME et al, 2000)

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Discussion

Conclusion