Genus Flagellotrema Ozaki, 1936 Emended diagnosis. Body elongate, fusiform, distinctly curved dorsoventrally; pale orange in life. Tegument always smooth. Ventral sucker round, posterior, not ventrosubterminal. Pharynx barrel-shaped or strongly pyriform, ventrosubterminal; fleshy pre-oral lip prominent. Oesophagus long, always with at least 1 complete loop which crosses midline, posterior thick-walled chamber absent, invested with glands along entire length. Oesophageal bulb well-developed, spheroid. Intestinal bifurcation immediately posterior to oesophageal bulb; caeca 2, blind, generally occupy approximately 1/4 of body length,; gastrodermis very thick. Testes 2, entire, ovoid, diagonal, in posterior third of body. Cirrus-sac present, encased in muscular capsule. Seminal vesicle partially external to cirrus-sac; bipartite. Pars prostatica large, penetrates cirrus-sac, surrounded by dense prostate gland cells. Cirrus-sac prominent, median, posterior to caeca, globular; ejaculatory duct long, convoluted within cirrus-sac, with distal expansion, eversible. Genital atrium large, with cilia-like lining. Genital pore, round, at level of termination of caeca. Ovary entire, intertesticular, dextral. Canalicular seminal receptacle prominent. Uterus entirely pre-ovarian. Opening of uterus unspecialised, enters genital atrium sinistral to cirrus-sac. Vitellarium follicular; follicles restricted anterior to testes, form distinctive X-shaped distribution in ventral field, dorsal field variable. Eggs large, tanned, opeculate, apparently unembryonated in utero. Excretory vesicle elongate, saccular, may reach to posterior margin of posterior testis. Excretory pore subterminal, opens on prominent papilla. Primary collecting ducts arise anterolaterally. Parasites of intestine of herbivorous Indo-Pacific marine teleosts (Acanthuridae and Siganidae). Type-species: Flagellotrema convolutum Ozaki, 1936.

Published as part of Hall, Kathryn A. & Cribb, Thomas H., 2008, Revision of Flagellotrema Ozaki, 1936 (Digenea, Gyliauchenidae Fukui, 1929), including the description of two species from acanthuroid fishes from the Great Barrier Reef, Queensland, Australia, pp. 1-35 in Zootaxa 1718 on page 5, DOI: 10.5281/zenodo.181038