EPIZOOTIOLOGICAL STUDY THE PENAEUS VANNAMEI IN TREE FARMS OF THE COLOMBIAN CARIBBEAN

Abstract

An epizootiological study of the mayor deseases affecting the penaeid shrimp Penaeus vannamei was performed from june 1994 throuh august, 1995 in tree farms located on the colombian Carebbean coast. The presence and prevalence of infectious agents such as bacteria, protozoa, viral inclusions bodies and changes histopatologicals was determinated by means of gross examination and histological analysis.. The relationship between these infection agents and specific disease was also studies. The presence of some viruses such a Baculovirus penaei, IHHNV, TSV and LOVV, were determinated by demostration of the cytopathical effects characteristic of these agent. Additionaly, a logistic regression analysis was used to determine the relationship between some clinical signs and the presence of the infectious agent; the risk factor of having the disease, was also determinated; thus, shrimp with tumors and deformities presented a risk almost two times higher having IHHNV disease, as determined by the presence of inclusion bodies Cowdry A (CAI’s) than those whitout deformities; in an analogous way, the risk factor of presenting alterations in the lymphoid organ (L.O) was higher in organisms that have exposed to the TSV desease, than in those were not. Bacterial infections an infestations by protozoa were also analyzed. Some differences concerning the presence and prevalence of some of the diseases according to the geographical location of the farms and the different climatic conditions in such the cultivation started, wer observed. Some physical-chemical variables such as salinity, where related to the presence and prevalence of some clinical signs.