Histology of the hepatopancreas and anterior intestine in the freshwater prawn Macrobrachium carcinus (Crustacea, Decapoda)

Abstract

The purpose of this study was to describe the structure of the midgut (hepatopancreas and intestine) in the endemic species, Macrobrachium carcinus. Thirty specimens were collected, and the midgut was fixed in Bouin's solution for histological and histochemical analyzes by light microscopy. The hepatopancreas consists of two lobes that connect to the end of the stomach by primary ducts, which originate secondary tubules or hepatopancreatic ducts, that branch into hepatopancreatic tubules. The hepatopancreatic duct presents a columnar epithelium composed of R-and F-cells with evident brush borders for absorption and storage. The hepatopancreatic tubule is lined by epithelium with five cell types (E, F, R, B, and M). The distal region presents all cell types, with a predominance of E-cells that correspond to epithelial renewal. The middle region presents F-and B-cells, characteristic of extracellular and intracellular digestion. The proximal region, with B-and R-cells, performs the final digestion, storage, and extrusion of the cells with

Morphological, Histological, and Physiological Responses of Female Orange Mud Crab, Scylla olivacea (Herbst, 1796), Fed with Different Dietary Lipid Levels

“…According to Hidir et al [38], the accumulation of B-cells during the late stage of ovarian maturation is closely related to the secretion of the digestive enzymes in the mud crabs, S. olivacea. The final product of this intracellular digestion will be further assimilated by the R-cells for metabolism and energy storage, either in the form of lipid or glycogen [60][61][62].…”

Probiotics: Comprehensive Exploration of the Growth Promotion Mechanisms in Shrimps

“…When examining the growth promotion effects of probiotics, gut physiology could not be neglected. The digestive tract of decapod crustaceans can be arbitrarily divided into three parts, namely the foregut, midgut, and hindgut [427,428] . Histological studies revealed that significant morphological changes typically occur in the midgut region of shrimps following probiotic administration [162] .…”

“…It is relatively large and typically constitutes 2 to 6% of the total body weight of a decapod [428] . The hepatopancreas is a versatile organ that plays essential roles in the digestive system through the regulation of numerous processes such as steroid hormone synthesis, digestive enzymes secretion, carbohydrate and lipid metabolism, nutrient absorption, storage, and distribution [427][428][429][430][431][432] . Besides, the hepatopancreas also acts as the main detoxification organ for shrimps, particularly during the rapid growth phase [432] .…”

“…The hepatopancreas is primarily composed of five different types of epithelial cells, namely Embryonalzellen/ embryonic cells (E cells), Fibrenzellen/ fibrillar cells (F cells), Blasenzellen/ blister/ vesicular/ extrusion cells (B cells), Restzellen/ resorptive/ reabsorption cells (R cells) and midget/ basal cells (M cells) [270,427,[433][434][435][436] . Meanwhile, M cells may not be present in some shrimp species [437] (see Figure 4).…”

“…Each cell type has unique features and functions (see Table 4). The small cuboidal E cells widely distributed at the distal tubules are undifferentiated cells responsible for epithelial renewal through mitotic divisions [427,437,438] . E cells serve as precursors for other cell types in the hepatopancreas.…”