2 PARASITIC COPEPODS, PSEUDOMYICOLA-SPINOSUS AND MODIOLICOLA-GRACILIS, ASSOCIATED WITH EDIBLE MUSSELS, MYTILUS-GALLOPROVINCIALIS AND MYTILUS-CALIFORNIANUS, FROM BAJA-CALIFORNIA, NW MEXICO
J. Caceresmartinez et al., 2 PARASITIC COPEPODS, PSEUDOMYICOLA-SPINOSUS AND MODIOLICOLA-GRACILIS, ASSOCIATED WITH EDIBLE MUSSELS, MYTILUS-GALLOPROVINCIALIS AND MYTILUS-CALIFORNIANUS, FROM BAJA-CALIFORNIA, NW MEXICO, Journal of shellfish research, 15(3), 1996, pp. 667-672
Mussel culture and fisheries are two increasing activities in Baja Cal
ifornia, NW Mexico. One of the risks for these activities is the prese
nce of harmful parasites like certain copepod species. This study was
carried out to determine the parasitic copepods associated with edible
mussels, Mytilus galloprovincialis Lmk. and Mytilus californianus Con
rad, from Baja California, NW Mexico, and to establish certain aspects
of their distribution, temporal fluctuation, and damage to their host
. The study was carried out at sites of contrasting environmental cond
itions: exposed rocky shores, protected shores, protected and polluted
areas, and culture area. Two species of parasitic copepods were found
inhabiting the mantle cavity and gills of mussels: Pseudomyicola spin
osus Raffaele and Monticelli (Mycolidae) and Modiolicola gracilis Wils
on (Clausidiidae). This is the first record of these copepods in Mexic
an waters. M. gracilis was found in M. galloprovincialis and M. califo
rnianus from all localities studied in numbers from 0 to 5 individuals
per host and a maximum prevalence of 26.66% in the first species, and
from 0 to 15 specimens per mussel and a maximum prevalence of 70% in
the second species. Its presence was relatively constant through the y
ear, with a slight increase in autumn and winter. P. spinosus, by cont
rast, was scarce or absent in M. californianus and M. galloprovinciali
s from exposed rocky shore environments. Its number and prevalence wer
e low in the mussel culture area. However, it was very abundant in M.
galloprovincialis from the protected and polluted environments, where
its numbers ranged from 0 to 59 copepods per mussel and a prevalence o
f 100%. Rates of infestation in mussels increased in autumn. Macroscop
ical damages associated with the presence of copepods were not detecte
d, and the histopathologic analysis did not reveal any damage to the t
issues of the host. However, there were more parasites in larger musse
ls, and most parasitized mussels showed a low condition index. P. spin
osus could be considered a potential threat to the mussel culture.