Some observations on Babesiosoma bettencourti (França, 1908) n. comb. (syns. Haemogregarina bettencourti França, 1908; Desseria bettencourti Siddall, 1995) from eels, Anguilla anguilla L., in Portugal

Abstract

The stages of a babesiosome were recorded from the erythrocytes of 73 out of 591 European eels, Anguilla anguilla L., captured in six rivers in northern and central Portugal during the period from January 1988 to July 1994. The prevalence, intensity and seasonality of the infection were recorded. Parasites were mostly intraerythrocytic in stained blood films. Unidivided and cruciform meronts, merozoites and gamonts were identified, and the meront stage was the most common. Mixed infections, in which the babesiosome coexisted with Trypanosoma granulosum Laveran & Mesnil, 1902, were present in 72 out of the 591 eels. In captive fish kept for up to 6 months, fluctuations in the levels of infection with the babesiosome were noted. The babesiosome existed in a similar geographical location, in what was presumed to be the same host and in the same host cell type as a parasite described earlier as Haemogregarina bettencourti. Furthermore, the gamonts of the babesiosome and the haemogregarine overlapped in morphometric description. Although H. bettencourti was recently assigned to the genus Desseria, a nomenclatural correction is proposed: a new combination, Babesiosoma bettencourti (França, 1908) (syns. Haemogregarina bettencourti França, 1908; Desseria bettencourti Siddall, 1995) in the European eel, Anguilla anguilla L. The definitive host of B. bettencourti is unknown.