Characteristics of the peripheral blood of the Anguillicola crassus (Kuwahara, Niimi et Tagaki, 1974) and Trypanosoma granulosum Laveran et Mesnil, 1902 infested eel (Anguilla anguilla L.) ascending the River Rega (north-western Poland).
The study was aimed at characterising the peripheral blood of eel (Anguilla anguilla L.) ascending the River Rega and infested with Anguillicola crassus (Kuwahara, Niimi et Itagaki, 1974) and Trypanosoma granulosum Laveran et Mesnil, 1902.


METHODS
Haematological assays were performed on 58 eel individuals caught in August and September 2001 and in July 2002. The nematode Anguillicola crassus was identified in the swim bladder lumen of 44 eel individuals. The mean infestation intensity amounted to 3.2, from 1 to 11 nematodes being found in a single host. Values of the basic haematological indices were determined from May-Grünwald-Giemsa (MGG)-stained blood smears. The data were subjected to statistical treatment involving the analysis of variance (ANOVA) and Kruskal-Wallis test (STATISTICA 6.0).


RESULTS
Microscope slides showed the eel to be infested by Trypanosma granulosum Laveran and Mesnil, 1902 occurring at a prevalence of 100%. Significant differences between the months of fish capture were revealed in the mean haematocrit, MCHC, and MCV values of all the eel, regardless if they were infested with Anguillicola crassus or not. On the other hand, there were no significant differences in the values of the parameters studied (E, Hb, Ht, L), including the haematological indices (MCH, MCHC, MCV), between the Anguillicola crassus-infested individuals and those free of the parasites, throughout the period of study. The relative and absolute leukograms showed a substantial domination of lymphocytes over other blood cells of the leukocyte line. The qualitative characteristics of the peripheral blood of the Anguillicola crassus-affected and -free eel were similar. The results indicate that some haematological parameters could be related to the season of capture. Effects of Trypanosoma granulosum on the blood seems to be distinct, but requires further, detailed studies, including research on the infestation intensity and taking into account characteristics of the parasite's morphological forms.
Rzad
Izabella
I
Department of Ecology and Environmental Protection, University of Szczecin, ul. Waska 13, 71 415 Szczecin. izarzad@gmail.com
Pilecka-Rapacz
Małgorzata
M
Sobecka
Ewa
E
D000811:Anguilla / Q000097:blood* / Q000469:parasitology*; D000818:Animals; D001769:Blood / Q000469:parasitology; D001773:Blood Cells / Q000473:pathology; D009348:Nematoda / Q000145:classification / Q000302:isolation & purification*; D011044:Poland; D045483:Rivers / Q000469:parasitology*; D013045:Species Specificity; D014345:Trypanosoma / Q000145:classification / Q000302:isolation & purification*