STRUCTURE AND DIVERSITY OF ENDOPARASITIC INFRACOMMUNITIES AND THE TROPHIC LEVEL OF PSEUDOPLATYSTOMA-CORRUSCANS AND SCHIZODON-BORELLI (OSTEICHTHYES) OF THE HIGH PARANA RIVER
Mh. Machado et al., STRUCTURE AND DIVERSITY OF ENDOPARASITIC INFRACOMMUNITIES AND THE TROPHIC LEVEL OF PSEUDOPLATYSTOMA-CORRUSCANS AND SCHIZODON-BORELLI (OSTEICHTHYES) OF THE HIGH PARANA RIVER, Memorias do Instituto Oswaldo Cruz, 91(4), 1996, pp. 441-448
One hundred and ten specimens of Pseudoplatystoma corruscans (Pimelodi
dae) and 582 specimens of Schizodon borelli (Anostomidae) collected in
the high Parana River were analyzed. On necropsy 74% of P. corruscans
were found to be parasitized; proteocephalidean cestodes presented th
e greatest number. With regard to S. borelli, the percentage of parasi
tism reached 19.42% and the nematode Cucullanus pinnai was the most ab
undant. The absence of correlation between the endoparasitic diversity
and the standard length of the two host species indicates that each o
ne presents homogeneity in alimentary behaviour during all its life ti
me, permiting the uniform recruitment of the same species of endoparas
ite during all its ontogenetic development. Independence of diversity
values in relation to sex of P. corruscans and S. borelli evidences th
at the ecological relationships are similar between males and females
in these species. Both host's infrapopulations presented a typical ove
rdispersed pattern of distribution with isolationist characteristics.