Two new species of Henneguya Thélohan, 1892 (Cnidaria: Bivalvulida: Myxobolidae) infecting gill of blue catfish, Ictalurus furcatus (Rafinesque) (Siluriformes: Ictaluridae) from the Tallapoosa River and Chesapeake Bay tributaries

We herein describe 2 new species of Henneguya Thélohan, 1892 (Bivalvulida: Myxobolidae), Henneguya auburnensis Ksepka and Bullard n. sp. and Henneguya chesapeakensis Ksepka, Walsh, and Bullard n. sp., infecting the inter-lamellar epithelium of cultured blue catfish (Ictalurus furcatus [Valenciennes, 1840] [Siluriformes: Ictaluridae]) from Saugahatchee Creek (Tallapoosa River; Auburn, Alabama) and the inter-lamellar epithelium of invasive blue catfish captured in Chesapeake Bay tributaries, respectively. Henneguya auburnensis resembles Henneguya mississippiensis Rosser, Griffin, Quiniou, Khoo, Greenway, Wise, and Pote, 2015, and Henneguya sutherlandi Griffin, Pote, Wise, Greenway, Mauel, and Camus, 2008, which both infect channel catfish (Ictalurus punctatus [Rafinesque, 1818] [Siluriformes: Ictaluridae]) in Mississippi, but differs from these species by having more polar tubule coils (10–12 vs. 8–9 and 6, respectively). Henneguya chesapeakensis resembles Henneguya longicauda Minchew, 1977, which infects channel catfish in Mississippi, but differs from this species by having shorter polar capsules (6.0–7.0 vs. 7.0–9.0). A phylogenetic analysis of the small subunit (SSU) rDNA recovered ictalurid-infecting Henneguya spp. as monophyletic, with H. auburnensis sister to a clade of Henneguya spp. that, except for H. chesapeakensis, infect the gill or adipose fin of channel catfish. Henneguya chesapeakensis was recovered sister to Henneguya ictaluri Pote, Hanson, and Shivaji, 2000. Histological sections of infected gill filaments revealed that the plasmodia of both new species developed within the inter-lamellar epithelium. The new species comprise the second and third species of Henneguya reported from blue catfish.