DAO 65:63-68 (2005)  -  doi:10.3354/dao065063

Blood protozoans in elasmobranchs of the family Rajidae from Galicia (NW Spain)

W. Aragort1, M. F. Alvarez2, J. L. Leiro2, M. L. Sanmartín1,2,*

1Avenida Principal Las Delicias, Unilab, Sanidad Animal, Instituto Nacional de Investigaciones Agrícolas (INIA).Maracay, Estado Aragua, Venezuela
2Instituto de Investigación y Análisis Alimentarios (IIAA), Universidad de Santiago de Compostela,C/Constantino Candeira s/n, 15782, Santiago de Compostela, Spain
*Corresponding author. Email: mpduran@usc.es

ABSTRACT: Blood smears from 132 skates Raja spp. captured on the continental shelf off Galicia (NW Spain) were examined for blood parasites. The skate species were Raja brachyura (n = 60), R. microocellata (n = 52) and a total of 20 specimens belonging to R. undulata, R. montagui and another 2 unidentified Raja species, all captured between March 1999 and March 2000. Two blood parasite species were found, Trypanosoma giganteum and Haemogregarina delagei. Of the 132 skates, 16% were infected only by T. giganteum, 17% only by H. delagei, and 5% by both T. giganteum and H. delagei. Both parasites showed highest prevalence in R. brachyura (22% T. giganteum only, 38% H. delagei only, 12% T. giganteum and H. delagei). Mean leucocyte percentages (n = 132 fish) were lymphocytes (43%), eosinophils (35%), neutrophils (20%) and monocytes (2%); basophils were not found. As far as we are aware, this eosinophil percentage is the highest reported to date for elasmobranchs. We did not detect any statistically significant differences in leucocyte percentages between infected and uninfected fish, between male and female fish, among species or among weight groups.

KEY WORDS: Haemogregarina delagei · Trypanosoma giganteum · Raja spp. · Blood parasites · Leucocyte counts · Galicia (NW Spain)

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