Phthinomita jonesi, Nolan & Cribb, 2006

Nolan, Matthew J. & Cribb, Thomas H., 2006, An exceptionally rich complex of Sanguinicolidae von Graff, 1907 (Platyhelminthes: Trematoda) from Siganidae, Labridae and Mullidae (Teleostei: Perciformes) from the Indo-west Pacific Region, Zootaxa 1218 (1), pp. 1-80 : 48-50

Phthinomita jonesi n. sp. ( Figs. 35–37 )

Type host: Siganus lineatus (Valenciennes) , Goldlined Rabbitfish ( Perciformes : Siganidae ).

Other hosts: S. argenteus (Quoy & Gaimard) , Forktail Rabbitfish; S. doliatus (Cuvier) , Barred Rabbitfish; S. vulpinus (Schlegel & Müller) , Foxface. ( Perciformes : Siganidae ).

Site in host: Intertrabecular spaces of ventricle (heart).

Type locality: Lizard Island, northern Great Barrier Reef (14°40’S 145°27’E), Queensland .

Material examined: ex S. lineatus, Lizard Island (QLD), Aug. 2002, May. 2004, thirtyfour specimens (Holotype no. QM G 225580; Paratype nos. QM G 225581–225589); ex S. argenteus, Lizard Island (QLD), Jan. 2003, (six specimens sequenced for ITS2); ex S. doliatus, Lizard Island (QLD), Jul. 2002, Aug. 2002, twenty­five partial and complete specimens (Paratype nos. QM G 225590–225602); ex S. vulpinus, Lizard Island (QLD), Aug. 2002, Jan. 2003, five specimens (Paratype nos. QM G 225603–225606).

Collector: M.J. Nolan.

Etymology

Specific name for our friend Mr Conor Jones for his help on a collecting trip to Heron Island.

Description

Based on 64 partial and complete whole mounts. With features of genus. Body not curving dorsally posteriorly, slightly notched at male pore. Intestine; posterior caeca irregular in outline, distal extremities expanded. Anterior testis originates posterior to intercaecal field, in posterior third of body, margins lobed. Posterior testis ovoid, margins lobed. Cirrus­sac spherical to tear­shaped. Internal seminal vesicle spherical, occupying ventral region of cirrus­sac; ejaculatory duct sinuous; prostatic cells small. Ovary ovoid, posterior to posterior margin of anterior testis. Oviduct originating at posterior margin of ovary, passing postero­dorsally, straight. Vitelline duct forming between anterior margin of cirrus­sac and posterior margin of ovary, sinuous, dextral to cirrus­sac and posterior margin of ovary; vitelline reservoir forming lateral to cirrus­sac, convoluted, entering oötype postero­dorsally. Oötype spherical, medial. Mehlis’ gland extending anteriorly to posterior margin of cirrus­sac, extending posteriorly to anterior margin of posterior testis. Uterus extending from oötype sinuously, ventral to oviduct. Uterine chamber forming posterior to posterior margin of ovary, straight, thin, narrowing posteriorly before female genital pore. Vitelline follicles extending anteriorly past intestinal bifurcation, extending posteriorly past anterior margin of uterine chamber, filling intercaecal field, passing posteriorly dorso­dextrally to anterior testis, anterior to anterior margin of ovary passes ventrally.

Remarks

The present material clearly belongs in the genus Phthinomita as it possesses characters differentially diagnostic of the genus. Phthinomita jonesi is distinguished by the combination of a body without a dorsal curve and only a slight notch level with the male pore, a body that is 45.8 times longer than wide on average, a spherical cirrus­sac, a uterine chamber that is 138 x 13 on average and vitelline follicles that extend anteriorly past the intestinal bifurcation.

There are in addition, 1–34 base differences (0.3–10.3% sequence divergence) between the ITS2 rDNA sequence of P. jonesi and the remaining Phthinomita species sequenced here. There is a single base different between the sequences from P. jonesi (25 replicates), from four sympatric host species off Lizard Island and P. littlewoodi (eight replicates) from S. lineatus (Heron Island) and S. corallinus (Lizard Island).

Figures

FIGURES 35–37. Phthinomita jonesi n. sp. from the intertrabecular spaces of the ventricle (heart) of Siganus lineatus off Lizard Island. 35. Adult. Dorsal anteriorly, twisting laterally at level of “arrow a”, ventral side to the left, whole mount. 36. Male terminal genitalia, dorsal view. 37. Female terminal genitalia, lateral view. Scale­bars: 35,37, 250 m; 36, 100 m.