THE REPONSES OF SHRIMP Artemesia longinaris TO VITAMIN K: HISTOLOGY OF MIDGUT GLAND.

FENUCCI, JORGE LINO; SARASA, MARIA VICTORIA; FERNÁNDEZ GIMENEZ, ANALIA VERÓNICA

Natal

Congreso; World Aquaculture Society 2011; 2011

World Aquaculture Society

The shrimp Artemesia longinaris is abundant penaeid species in the Argentine coastal waters. As the availability of this species undergoes yearly fluctuations, it is important to establish the feasibility of culturing. Diet quality is an important condition for a successful culture of crustaceans. Numerous studies have revealed that fat-soluble vitamins are essential in most animals for normal health and life functions. Little information is available on the role of vitamin K in shrimp nutrition. This vitamin has been reported to be required for Marsupenaeus japonicus and Penaeus monodon. The purpose of the present study was studied the response of histology of midgut gland of Artemesia longinaris fed with diets containing different levels of vitamin K. Four semi purified diets (vitamin free casein, manioc starch, squid protein concentrate and vitamin free fish oil) were designed containing 0 (K0); 160 (K160), 240 (K240) and 320 (K320) mg vitamin K/kg diet and complete diet (C) (fishmeal, soybean meal as main protein sources) as control. Shrimps (2,5g mean weight) were obtained from a commercial fisherman and placed in 150 l glass aquaria (33‰ salinity, 20°C, pH 7, 13:11 h photoperiod). Each diet was tested in three replicate groups of 8 prawns/m2 during 6 weeks. At the end of trial specimens in intermolt stage were placed on ice and midgut glands were dissected, fixed in Davidson fluid for 24 h, dehydrated in a progressive series of ethanol and embedded in butylparaffin and paraffin. Sections of 5 µm were stained with hematoxylin-eosin. Midgut gland from shrimps fed with C and K240 exhibited normal histology and the cell types (R, F and B) were well preserved and having a conspicuous brush border. In A. longinaris fed diet K0; K160 and K320, the epithelial cells showed signs of shrinkage and the lumina were enlarged in the affected tubules. Apical cells desquamation, damaged basal lamina and in some cases hypertrophy, haemocytic infiltration and protein precipitation in the intertubular space are also observed. Histological analysis is important due to midgut gland cells of invertebrates reflecting the nutritional value of a diet. The most notable changes reported this work, have been reported for this species fed with diets deficient in vitamins A, E and D. In the present study, histological analysis indicate that a vitamin K (240 mg/kg diet) supplemented diet is essential to maintain the normal structure of midgut gland of Artemesia longinaris.