A NEW SPECIES OF HENNEGUYA THÉLOHAN, 1892 (CNIDARIA: BIVALVULIDA: MYXOBOLIDAE) INFECTING THE SUBMUCOSA OF THE INTESTINE AND PYLORIC CECA OF RED DRUM, SCIAENOPS OCELLATUS (LINNAEUS) (PERCIFORMES: SCIAENIDAE) FROM COASTAL ALABAMA.

Abstract

A new species of Henneguya Thélohan, 1892 (Bivalvulida: Myxobolidae) is described from the submucosa of the intestine and pyloric ceca of red drum (Sciaenops ocellatus [Linnaeus, 1766] [Perciformes: Sciaenidae]) from the Gulf of Mexico off Gulf Shores, Alabama. Henneguya albomaculata n. sp. differs from all congeners by the combination of myxospore dimensions, polar tubule coil count, the presence of an iodinophilic vacuole in the sporoplasm, and small-subunit ribosomal deoxyribonucleic acid (SSU rDNA) sequence. A phylogenetic analysis of the SSU rDNA recovered H. albomaculata sister to Henneguya cynosioniDykova, de Buron, Roumillat, and Fiala, 2011 in a clade composed of 11 species of Henneguya and 1 species of Myxobolus Bütschli, 1882 (Bivalvulida: Myxobolidae) that collectively infect fishes in marine or estuarine systems. Histologic sections of infected intestine and pyloric ceca revealed plasmodia of H. albomaculata n. sp. developing in the loose connective tissue of the submucosa. The new species comprises the second species of Henneguya reported from red drum.