PREVALENCE AND REPRODUCTION OF BOPYRINA ABBREVIATA (ISOPODA, BOPYRIDAE) IN LAGUNA DE TERMINOS, SW GULF OF MEXICO

Bopyrina abbreviata Richardson, 1904 parasitizes caridean Hippolytidae, important consumers of submerged aquatic vegetation. This study evaluates the prevalence and reproductive aspects of the parasite at two-month intervals during an annual cycle in the Gulf of Mexico. The average prevalence of B. abbreviata was 0.37% (range 0.01-1.47%). Sex ratio of infested host was skewed to females (X-2 = 138.90, df = 1; P < 0.01) throughout the year (X-2 = 11.18, df = 5; P > 0.01). The parasite pattern distribution on its host was aggregated (ID = 1.83; d = 19.25). Host shrimps were infested principally by a couple of parasites, male and female, (74.7%). The intensity of infestation did not vary with host sex (t = 1.69; P > 0.05) but varied with shrimp size classes (t = 2.19; P < 0.05). The relationship between the host cephalothorax length and parasite total length was positive (r(2) = 0.91), as was that between fecundity and size of B. abbreviata (r(2) = 0.58). The main parasite recruitment took place during February and April, and its reproductive peak from April to June; this seems to reflect the mating period of the parasite larvae in the young hosts and the simultaneous growth of both species. The size at maturity of B. abbreviata was 1.64 mm TL and females produced an average of 637.3 +/- 336 embryos, which increased their volume from 0.0005 mm(3) to 0.0008 mm(3) in stages I to III, respectively. Loss of eggs in B. abbreviata was estimated at 7.21%.