Faunal survey and identification key for the trematodes (Platyhelminthes: Digenea) infecting Potamopyrgus antipodarum (Gastropoda: Hydrobiidae) as first intermediate host Author Hechinger, Ryan F. text Zootaxa 2012 3418 1 27 journal article 10.5281/zenodo.210378 79309026-26b8-49e2-b833-39a654314ff8 1175-5326 210378 Key to trematodes infecting Potamopyrgus antipodarum as first intermediate host [Species number in brackets preceding name matches numbering in Fig. 1 and Table 1, and the ordering in the species accounts section.] 1. Lacking daughter parthenitae (sporocysts or rediae), free embryos appear to develop directly to over 100 spherical metacercariae that fill much of visceral mass................................................. [13] Microphallus sp. “livelyi” - With parthenitae...................................................................................... 2 2. Cercariae lacking tail, with oral stylet.......................................... [15] Acaudate xiphidiocercaria sp. I - Cercariae with tail (small cup-like, simple, forked, finned or bristled); with or without stylet.......................... 3 3 Tail small and cup-like (not more than 2x long as wide); stylet with two anterior points…........[11, 12] Coitocaecum spp. - Tail elongate (e.g.,> 3x long as wide); if stylet present, lacking two anterior points.................................. 4 4 Tail forked........................................................................................... 5 - Tail not-forked........................................................................................ 7 5 Tail stem and furcae each about same length as body............................................ [1] Apatemon sp. I - Tail stem at least 2x body length; caudal furcae short (much less than 1/2 stem length).................. (aporocotylids) 6 6 Cercaria smaller than 6b (body <100 long, tail stem <200 long); sporocysts round to slightly oblong.. [2] Aporocotylid sp. I - Cercaria larger than 6a (body> 130 long, tail stem> 200 long); sporocysts elongate................ [3] Aporocotylid sp. II 7 Cercaria with oral stylet (may be minute & non-descript—see Plagiorchioid sp. I).................................. 8 - Cercaria lacking oral stylet............................................................................. 11 8 With virgula organ (sack-like organ in posterior oral sucker).................................................... 9 - Lacking virgula organ................................................................................. 10 9 Cercaria smaller than 9b (body <100 long), virgula organ wider than long, faintly bipartite or not bipartite.[16] Virgulate sp. I - Cercaria larger than 9a (body> 130 long); virgule organ longer than wide, clearly bipartite............ [17] Virgulate sp. II 10 With prominent ventral sucker, Y-shaped bladder, small bullet-shaped stylet (less than 1/5 oral sucker length), and obscuring cystogenous glands throughout most of body.............................................. [18] Plagiorchioid sp. I - Lacking ventral sucker, with elongate stylet (> ½ oral sucker length); body translucent with prominent penetration glands just posterior to equator............................................................[14] Microphallus sp. “poulini” 11 With pigmented eyespots.............................................................................. 12 - Lacking pigmented eyespots............................................................................ 17 12 With ventral sucker................................................................................... 13 - Lacking ventral sucker................................................................................ 15 13 Tail simple, not ornate............................................................. [19] Gymnocephalous sp. I - Tail with lateral bristles................................................................... (lepocreadiids) 14 14 With 4 pairs of penetration glands................................................... [8] Stegodexamine anguillae - With 6 pairs of penetration glands........................................................ [9] Lepocreadiid sp. II 15 Lacking dorso-ventral tail fin; sometimes with medial eye....................................[5, 6] Notocotylus spp. - With dorso-ventral tail fin.............................................................................. 16 16 With penetration glands (gland bodies just pre-equator and gland ducts empty at anterior oral sucker); lacking longitudinal pig- ment bands..................................................................... [10] Telogaster opisthorchis - Lacking penetration glands; with two longitudinal pigment bands........................... [7] Pronocephaloid sp. IV 17 Lacking ventral sucker; tail simple; body filled with opaque cystogenous glands (white with reflected light); prominent lateral arms of excretory system connect anteriorly; smaller than 17b (body length ~500)................[4] Pronocephaloid sp. I - With ventral sucker; tail with dorso-ventral fin; larger than 17a (body length ~1000)…......... [20] Gymnocephalous sp. II