Morfometria do tegumento em juvenis do camarão de água doce Macrobrachium rosenbergii

Abstract

Macrobrachium rosenbergii is the most cultivated freshwater prawn species in Brazil, however, little is known about the physiology of the animal, especially regarding the moulting cycle. Thus, the present study had as objective to describe the morphometry of the layers of the tegument of M. rosenbergii, according to the chronological stages of the molting cycle. The animals were collected in the shrimp fattening nurseries of the Carcinculature Laboratory of the UFPB, in Bananeiras-PB. For this, eight shrimps with 9.3 ± 1.4g of each stage of the moulting cycle, classified by the method of setogenesis in A, B, C, D0, D1, D2 or D3, were collected, adding 56 animals analyzed, being collected The second abdominal segment and fixed in 10% formalin. Histological analyzes were performed in the histology laboratory of the PPGCan-UFPB according to the standard histological protocol and later observed with the Motic Image Plus 2.0 image program and statistically analyzed with the Graph Prism 6.0 computer program. As results, the layers of the integument were described: epicutícula, calcific layer, epidermis and connective tissue. The thickness of the calcified layer and the epidermis varied according to the molting cycle. The calcification had the lowest thickness (6.4 + 1.6μm) in stage A, reaching the peak in stage C (39.3 + 11.6μm), then decreasing. With the epidermis was the inverse, with maximum in stages A (44.0 + 8.4μm) and D3 (44.6 + 12.0μm), reaching the minimum in stage C (27.2 + 9.5μm). Thus, these results highlight the intense physiological processes that occurred in the tegument of M. rosenbergii in the pre and post-molt moments.