Biological and Pathological aspects of parasitism in the branchial chamber of Palaemonetes argentinus (Crustacea Decapoda) by infestación with Probopyrus cf. oviformis (Crustacea Isopoda).

MIGUEL SCHULDT; RODRIGUES CAPITULO, ALBERTO

JOURNAL OF INVERTEBRATE PATHOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 1985 vol. 45 p. 139 - 146

0022-2011

In this paper, adaptations and microanatomic changes in the branchial chamber, as well as influence of parasitosis on the reproductive function of shrimp, are analyzed. Probopyrus cf. oviformis was observed in the branchial chamber of shrimps of both sexes, with an infestation rate of 29%. The infestation frequency in relation to sex and size was not uniform, and two trends were observed: a higher frequency in bigger males in contrast to females, with less infestation frequency in older individuals. This aspect was related to changes in the sex ratio of shrimps, infested and noninfested, with the following conclusions: (1) Sexual inversions were not observed in females of P. argentinus; (2) male infestation with P. cf. oviformis showed tertiary sexual rate bias. It occurred because the metabolic parasite-host relationship led to an increase in size. These infested males were incorporated into a normal population characterized by females being bigger than males. The morphological and functional changes observed were (1) branchial chamber reduction, slendering of the cephalothorax lateral wall, together with local injury (oxygen consumption was below the normal values; and (2) the ovaries of infested females of P. argentinus remained stationary in incipient maturity (secondary vitellogenesis was not observed).