Effects of metacercariae (Digenea: Microphallidae) on the hepatopancreas of Chasmagnathus granulata (Decapoda: Grapsidae)

Abstract

We analysed the effects of lnfection by Microphallus szldati metacercarlae on carbohydrate (glucose and glycogen) levels and histopathology of the hepatopan- cieas of the estuarine crab Chasmagnathus granulata No slg- nlflcant differences In infection were found between the left and nght sides of the hepatopancreas and infection intensity ranged from 2 to 802 The mean intensi ty of rlletacercarlae cysts was 54 79 k 12 64 (k1 SE) wlth a prevalence of 90 1% Hepatopancreat~c glycogen was higher In infected crabs (28 2 t 2 2 m g g-l tlssue) than in non-lnfected ones (21 7 2 1 9 my g ' tissue) Further, hlgh intensltles of infection (>6 parasites per tissue section) promoted necrosls of the hepatopancreatlc tubules and hemocytic infiltration around the cysts Thus the presence of M szjdatj metacercarlae in the hepatopancreas of C granulata can cause structural damage to the tissue altering its glycogen levels and can be considered as a potential physiological stress factor