Lobosorchis polygongylus, Miller, Terrence L., Downie, Abigail J. & Cribb, Thomas H., 2009

Miller, Terrence L., Downie, Abigail J. & Cribb, Thomas H., 2009, Morphological disparity despite genetic similarity; new species of Lobosorchis Miller & Cribb, 2005 (Digenea: Cryptogonimidae) from the Great Barrier Reef and the Maldives, Zootaxa 1992, pp. 37-52 : 40-42

Lobosorchis polygongylus n. sp.

( Fig. 1 )

Type host: Lutjanus gibbus (Forsskål) , Perciformes , Lutjanidae , humpback red snapper.

Type locality: Rasdhoo Atoll (4º16’N; 72º58’E), Maldives.

Additional localities: Lizard Island, Great Barrier Reef (14º40’S; 145º27’E), Queensland, Australia.

Site: Intestine and pyloric caeca.

Prevalence: 5 of 5 (100%) at Rasdhoo Atoll; 2 of 7 (29%) at Lizard Island.

Molecular sequence data: ITS, 3 individuals from Lizard Island, 4 individuals from the Maldives; LSU, 3 individuals from Lizard Island, 3 individuals from the Maldives.

Deposited specimens: holotype G 230563, 12 paratypes G 230564 -G 230575.

GenBank accession numbers: ITS ( FJ154900 ), LSU ( FJ154902 ).

Etymology: The epithet polygongylus is derived from the Greek poly, meaning many and the Greek gongylos, meaning ball-shaped, round or spherical, referring to the multiple testicular follicles present in this species.

Description: Based on 13 specimens. Body oval, longer than wide, 959 (598–1,176) long by 580 (374–688) wide; length/width ratio 1.7 (1.4–1.9). Oral sucker 123 (78–154) long by 217 (165–254) wide. Oral spines 70 (60–81), length 19 (8–27). Ventral sucker 68 (53–80) long by 78 (59–88) wide. Ratio oral/ventral sucker width 2.8 (2.5–3). Forebody occupying 34 (31–36)% of body length. Prepharynx shorter than oesophagus, 15 (6–22) long. Pharynx 92 (62–115) long by 93 (70–109) wide. Ventral sucker/pharynx width ratio 0.8 (0.8–0.9). Oesophagus 36 (19–48) long. Intestinal bifurcation between ventral sucker and pharynx. Intestinal caeca blind, 668 (390–852) long, terminate close to posterior end of body. Testes multiple, in two symmetrical groups, total number 19 (13–25), in mid-hindbody, individual testes 87 (45–131) long by 99 (43–179) wide. Seminal vesicle tubulosaccular, between ovary and ventral sucker. Gonotyl a small lobe arising from anterior wall of ventrogenital sac. Genital pore immediately anterior to ventral sucker. Ovary deeply lobed, immediately anterior and adjacent to testes, 171 (122–202) long by 190 (134–256) wide. Laurer's canal present. Seminal receptacle saccular, dextral or sinistral to seminal vesicle, between ovary and ventral sucker. Vitelline follicles confined almost entirely to forebody, confluent dorsally, extend from slightly posterior to ventral sucker to near posterior margin of oral sucker. Uterine coils restricted to hindbody, extend from posterior end of body to ventral sucker. Eggs small, darkly tanned, 18 (15–21) long by 8 (7–9) wide. Excretory vesicle Yshaped, bifurcates dorsal to ovary; arms extend to pharynx, 757 (442–944) long. Excretory pore opens at posterior end of body.

Figures

FIGURE 1. Lobosorchis polygongylus n. sp. from the intestine of Lutjanus gibbus off Rasdhoo Atoll, Maldives. Ventral view of holotype. Scale bar = 200 µm.