Histoarchitectural Features of the Hepatopancreas of the Amazon River Prawn Macrobrachium amazonicum

Abstract

SUMMARY:In decapod crustaceans, the digestive gland is concerned with the digestion, absorption of nutrients, the storage of reserves and excretion. The metabolism and the histological and histochemical changes of the hepatopancreas are observed in response to physiological demands as moult, reproduction, digestive process. Thus the hepatopancreas structure should be recognized to provide important morphological information to future studies involving the nutrition requirements of freshwater prawn culture. In this study, second-generation Macrobrachium amazonicum produced from wild broodstock collected in the state of Pará in Brazil were used. Thirty adult male and female M. amazonicum were selected and randomly transferred to five experimental units for macroscopic and microscopic studies. The hepatopancreas of M. amazonicum is a large, yellowish-brown, compact organ, which occupies much of the cephalothoracic cavity. It has right and left halves that are enclosed together in a laminar connective tissue capsule, and at the same time they are separated by an interstitial connective tissue. The two halves are thereby called the right and left hepatopancreatic lobes. The principal tubule gives rise to four secondary tubules at each hepatopancreatic lobe. The morphological and functional unit consists of a blind-ended hepatopancreatic tubule, considered in the present study as the hepatopancreatic lobule. Each hepatopancreatic tubule can be subdivided into distal, medial and proximal zones. The hepatopancreatic tubule is lined by a pseudostratified epithelium that consists of five different cell types, which include the E-cell (embryonic), F-cell (fibrillar), B-cell (blister-like), R-cell (resorptive) and M-cell (midgut or basal). It is important to emphasize that the function of each cell type in the hepatopancreas during the digestive cycle is not yet established for decapods.KEY WORDS: Hepatopancreas; Morphology; Decapoda; Macrobrachium amazonicum. INTRODUCCIÓNDecapod crustaceans have a digestive gland associated to the midgut. It has received different names from which hepatopancreas is the most accepted (Van Weel, 1974). The hepatopancreas is concerned with the digestion, absorption of nutrients, storage of reserves and excretion (Johnston et al., 1998;Sousa & Petriella, 2000). It is also involved in the synthesis of digestive enzymes (Icely & Nott, 1992). In general, the organ occupies much of the cephalothoracic cavity and is connected to the pyloric stomach by two primary ducts. Each duct branches into many hepatopancreatic tubules, which comprise the hepatopancreas (Johnston et al.; Souza & Petriella). Each hepatopancreatic tubule consists of different cell types, which include the E-cell (embryonic), R-cell (resorptive), F-cell (fibrillar), B-cell (blisterlike) and M-cell (midget or basal) (Gibson & Barker;Al-Mohanna & Nott, 1987Caceci et al., 1988;Icely & Nott). The different cellular types have specific roles in the cyclical digestive process (Hirsch & Jacobs, 1992;Gibson & Barker;Sousa & Petriella). Th...

Effect of dietary cornstarch levels on growth performance, enzyme activity and hepatopancreas histology of juvenile red swamp crayfish, Procambarus clarkii (Girard)

“…And it is composed of numerous blindend tubules, with each tubule consisting of different epithelial cell types, i.e. E-cell (embryonic), R-cell (resorptive), F-cell (fibrillar), and B-cell (blisterlike) Nott, 1987, 1989;Caceci et al, 1988;Calvo et al, 2011;Franceschini-Vicentini et al, 2009). Histological analysis of the hepatopancreas has been used as a practical means for assessing the nutritional condition in the shrimp culture (Gimenez et al, 2004;Reddy et al, 1999).…”

Starvation resistance in juvenile freshwater crayfish

“…E-cell (embryonic), R-cell (resorptive), F-cell (fibrillar), and B-cell (blisterlike) (Al-Mohanna & Nott 1986Franceschini-Vicentini et al 2009, Icely & Nott 1992. Hence, the capability of a decapod to survive transitory lack of food and to subsequently recover from such periods depends on adaptive physiological and behavioral traits and, especially, on its capacity to store energy in the hepatopancreas.…”

Indicadores de condicion larvaria aplicados al camaron de rio del norte Cryphiops caementarius (Molina, 1782), en condiciones de cultivo controlado

“…El estado de la glándula digestiva, se observó constantemente con contenidos alimenticios, a pesar de que en ocasiones el intestino estuviera ya evacuado. Este hecho permite comprobar una de las principales funciones de esta glándula, relacionadas con el almacenaje de nutrientes y reservas energéticas (Biesiot & McDowell, 1995;Hammer et al, 2000, Franceschini et al, 2009. Los valores promedios para este indicador (1,5), con un mínimo de 0,7 permite determinar que probablemente las larvas están permanentemente consumiendo y procesando el alimento, y a su vez manteniendo reservas por periodos prolongados de tiempo, lo cual podría sustentar momentos de ayuno fisiológico, por ejemplo en periodos de muda (Fig.…”

“…No obstante, el funcionamiento de la glándula digestiva también depende de la digestibilidad de los alimentos, su asimilación y actividad enzimática (Jones et al, 1997). La glándula digestiva en crustáceos decápodos ha sido identificada como responsable, entre otras funciones, de la síntesis y secreción de enzimas digestivas, de la absorción de nutrientes ya digeridos en el estómago y del lugar para el almacenaje de reservas energéticas, señalando además la existencia de cambios morfológicos y funcionales de esta glándula durante el desarrollo larvario y principalmente en juveniles (Lovett & Felder, 1990;Biesiot & McDowell, 1995;Hammer et al, 2000, Franceschini et al, 2009.…”