Emendation and new species of Hapalorhynchus Stunkard, 1922 (Digenea: Schistosomatoidea) from musk turtles (Kinosternidae: Sternotherus) in Alabama and Florida rivers

Abstract Hapalorhynchus Stunkard, 1922 is emended based on morphological study of existing museum specimens (type and voucher specimens) and newly-collected specimens infecting musk turtles (Testudines: Kinosternidae: Sternotherus spp.) from rivers in Alabama and Florida (USA). Hapalorhynchus conecuhensis n. sp. is described from an innominate musk turtle, Sternotherus cf. minor , (type host) from Blue Spring (31°5′27.64″N, 86°30′53.21″W; Pensacola Bay Basin, Alabama) and the loggerhead musk turtle, Sternotherus minor (Agassiz, 1857) from the Wacissa River (30°20′24.73″N, 83°59′27.56″W; Apalachee Bay Basin, Florida). It differs from congeners by lacking a body constriction at level of the ventral sucker, paired anterior caeca, and a transverse ovary as well as by having a small ventral sucker, proportionally short posterior caeca, nearly equally-sized anterior and posterior testes, a small cirrus sac, and a uterus extending dorsal to the ovary and the anterior testis. Specimens of Hapalorhynchus reelfooti Byrd, 1939 infected loggerhead musk turtles, stripe-necked musk turtles ( Sternotherus peltifer Smith and Glass, 1947), Eastern musk turtles ( Sternotherus odoratus [Latreille in Sonnini and Latreille, 1801]), and S. cf. minor . Those of Hapalorhynchus cf. stunkardi infected S. minor and S. odoratus . Sternothorus minor , S. peltifer , and S. cf. minor plus S. minor and S. odoratus are new host records for H. reelfooti and H. cf. stunkardi , respectively. This is the first report of an infected musk turtle from the Coosa and Tallapoosa Rivers (Mobile-Tensaw River Basin), Pensacola Bay Basin, or Apalachee Bay Basin. Sequence analysis of the large subunit rDNA (28S) showed a strongly-supported clade for Hapalorhynchus .