Phyllodistomum centropomi sp. n. (Digenea: Gorgoderidae), a parasite of the fat snook, Centropomus parallelus (Osteichthyes: Centropomidae), in the Papaloapan River at Tlacotalpan, Veracruz State, Mexico Author Mendoza-Garfias, Berenit Author León, Gerardo Pérez-Ponce De text Zootaxa 2005 1056 43 51 journal article 10.5281/zenodo.170106 b1532ea4-4297-476b-9531-45d628ae8971 1175­5326 170106 Phyllodistomum centropomi n. sp. Type­host: Centropomus paralellus Poey, 1860 Type­locality: Papaloapan River at Tlacotalpan, Veracruz State, Mexico ( 18°36’28”N , 95°39’06”W ). Site: Urinary bladder. Type material: Holotype No. 4504 and 9 paratypes (4505) deposited in the Colección Nacional de Helmintos, Mexico City, Mexico ( CNHE ). Two paratypes deposited in the U.S. National Parasite Collection, Beltsville, Maryland ( USNPC ) No. 096463–096464. Prevalence of infection (infected hosts/analyzed hosts, percentage): 13/39, 33.33%. Mean abundance: 26 worms/39 hosts (0.66 worms per analyzed host). Etymology: This species is named after the host generic name. Description ( Figs 1 A–B, 2A–D) Body oblong, expanded posterior to ventral sucker, aspinous, with undulations in lateral margins of hindbody, 1796–2610 (2200) long by 1252–1651 (1450) wide at level of posterior region. Forebody sub­cylindrical, representing 1/3 of total body length. Hindbody discoid, with 3 or 4 slight undulations possessing series of muscular indentations from the level of testes to posterior extremity. Tegument with numerous papillae. Oral sucker 219–275 (248) x 214–274 (248), subterminal, showing 20 dome­type papillae in symmetrical arrangement. Ventral sucker in second quarter of body, not occupying full body width, 232–286 (250) x 206–279 (251). Sucker ratios: lengths of oral sucker to acetabulum 1:1.08–1:1.18 (1:1.09); widths of same organs: 1:0.83–1:1.33 (1:1.02). Prepharynx and pharynx lacking. Esophagus 97–215 (138) long by 10–34 (20) wide. Ceca long, narrow, running laterally along the body and terminating at end of hindbody. FIGURE 1. Phyllodistomum centropomi n. sp. A) Holotype, ventral view, scale­bar : 100 µm. B) Paratype, detail of the terminal ends of the reproductive tracts, scale­bar : 10 µm. C = Ceca, MI = muscular indentations, O = Ovary, OS = Oral sucker, SV = Seminal Vesicle, T = Testes, UN = Undulations, U = Uterus, VG = Vitelline glands, VS = Ventral sucker FIGURE 2. A) Scanning Electron Microscopy of the of the forebody of P. centropomi , showing genital pore. B) Oral sucker showing the stylet scar. C) Ventral sucker showing 2 internal domelike papillae. D) Higher magnification of body surface showing a dome­like papillae. Testes 2, slightly lobed, symmetrical, in middle region of body, postovarian; right 259–402 (332) long, 225–388 (266) wide; left 230–559 (346) long, 194–347 (270) wide. Seminal vesicle saclike in appearance, 80–109 (95) long, opening via genital pore. Pars prostatica and ejaculatory duct not observed. Genital pore mid­ventral, between acetabulum and intestinal bifurcation. Ovary entire, ovoid, anterior and oblique to right testis, 150–195 (169) long, 135–229 (192) wide. Oviduct arises dorsally, giving off Laurer´s canal and receiving common vitelline duct, opens into the ootype which is surrounded by Mehlis´gland. Uterus arises from ootype, filling extra­ and inter­cecal area, occupying most of hindbody, ascending arm followed by muscular metraterm which opens via genital pore. Eggs from distal portion of uterus oval 19–32 (25) long, 15–24 (19) wide. Vitelline glands comprises 2 compact oval masses, located posterolaterally to ovary; right 91–130 (111) long, 80–117 (95) wide; left 99–153 (120) long, 83–134 (99) wide. I­shaped excretory bladder tubular, dorsal to uterus, extends to level of testes. Excretory pore terminal.