Associations between two trematode parasites, an ectosymbiotic annelid, and Thiara (Tarebia) granifera (Gastropoda) in Jamaica.

This work describes associations of Thiara (Tarebia) granifera, its larval trematode community, and Chaetogaster limnaei limnaei at a freshwater reservoir in Jamaica. Larvae of 2 trematodes were present, i.e., a notocotylid (15.3%) and Philophthalmus sp. (1.3%), in 3,575 T. granifera examined. The prevalence of both infections increased with snail shell length (H  =  56, P < 0.01, H  =  23.1, P < 0.01, respectively). Only 3.0% (n  =  595) of infected snails possessed reproductive stages, compared with 90.3% (n  =  2,980) of uninfected snails (χ(2)  =  2,059.8, df  =  1, P < 0.001); both trematodes negatively impacted snail reproduction. Chaetogaster l. limnaei occurred within the mantle cavity of T. granifera with a prevalence of 2.3% (n  =  3,575); intensity ranged from 1 to 6 annelids. Notocotylid larvae occurred in 32.5% (n  =  83) of snails also harboring C. l. limnaei, compared with 14.9% (n  =  3,492) of snails lacking the annelid (χ(2)  =  18.127; P < 0.001). Chaetogaster l. limnaei appears not to influence the recruitment of egg-transmitted, notocotylid infections to snails. Ingestion of emergent cercariae by the annelid was observed; this may impact transmission of the parasite. The article presents the first report of a notocotylid and C. l. limnaei in T. granifera, and of Philophthalmus sp. in Jamaica.