USGS2025
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.