Field Guide to Venomous and Medically Important Invertebrates ...

Figure 269. A nudibranch (Flabellina rubrolineata). Photo: Great Barrier Reef Park Authority.
Figure 270. A nudibranch (Glaucus atlanticus). Photo: Gary Cobb.
Figure 271. A nudibranch (Hermissendra crassicornis). Photo: David W. Behrens.
Figure 272. An unidentified nudibranch. Photo: Stanford University.
Figure 273. An unidentified nudibranch, Honduras. Photo: Joe Fries.
Several genera of freshwater snails serve as the intermediate hosts of parasitic flukes
Schistosoma spp. which can cause potentially fatal schistosomiasis in humans. These host snails
include the genera Bulinus, Biomphalaria, and Oncomelania. However, because these snails can
be quite difficult to identify, all freshwater snails within the range of schistosomiasis should be
considered as suspect. Bulinus spp. occur in the Africa, Middle East, Madagascar, Mauritius,
India. Australorbis spp. (Biomphalaria spp.) also is a widely distributed genus occurring in
Africa, Middle East, Madagascar, South America, and some Caribbean Islands. This genus also
occurs in the southern United States southward through Central America but it is not known to
serve as a schistosome host in these latter areas. Members of the genus Oncolmelania are
distributed widely throughout Asia including China, Japan, the Philippines, and Sulawesi
(Celebes). Oncomelania snails are amphibious and readily climb on vegetation and moist soils
near the water source.
Figure 274. Biomphalaria sp. Photo: University of Hamburg.
Figure 275. Bulinus globosus. Photo: Eric Genevelle.
Figure 276. Oncomelania hupensis. Photo: P. R. Hubai.