Anguillicola novaezelandiae

Dangel, K. C., Keppel, M., Le, T. T. Y., Grabner, D. & Sures, B., 2015, Competing invaders: Performance of two Anguillicola species in Lake Bracciano, International Journal for Parasitology: Parasites and Wildlife 4 (1), pp. 119-124 : 120-121

3.2. Anguillicola novaezelandiae

Even though A. novaezelandiae was introduced to Lake Bracciano as early as 1975, it was first recorded seven years later ( Paggi et al., 1982). Since data of its occurrence are only sparse, one can only speculate whether the parasite may have been introduced several times or only once ( Moravec, 2006). Until the description of the species and the revision of the genus by Moravec and Taraschewski (1988), records of the species were mentioned as A. australiensis or maybe even A. crassus and a precise species determination is therefore often not clear. Records of A. australiensis in European eels in Italy during the 1980s could possibly be A. novaezelandiae ( Saroglia et al., 1985; Di Cave, 1986; Sarti, 1986).

Moravec et al. (1994a) conducted experimental infections of the copepod species Cyclops strenuus successfully with L2 of A. novaezelandiae originating from Lake Bracciano from October 1993 and studied the life cycle and morphology of the species in the intermediate and final host. These as well as other authors did not record any swim bladder damages due to A. novaezelandiae infections in any eel species ( Paggi et al., 1982; Moravec et al., 1994a; Münderle, 2005). Addtitionally, the detailed experimental infection study of Dangel et al. (2013) revealed great differences in the development of A. novaezelandiae in European eels compared to A. crassus . While A. novaezelandiae matures in a synchronized fashion and eggs containing L2 were found 120 days post infection at the earliest, the development of A. crassus is less uniform, so that eggs are emitted earlier and over longer time periods. Furthermore, infrapopulations of A. crassus seem to be regulated by density, whereas no density-dependent effects for A. novaezelandiae could be recorded, even when the number of administered larvae was doubled (40 instead of 20), it did not noticeably change the maximum adult population size ( Fazio et al., 2008; Dangel et al., 2013; Weclawski et al., 2013).

Although there is no information about the range of intermediate or paratenic hosts so far, fundamental differences to A. crassus do not appear to be likely. In its endemic range in New Zealand, A. novaezelandiae seems to show a seasonal pattern, which is a unique finding for a species of the genus ( Dangel and Sures, 2013).