Phthinomita ingramae, 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 : 45-46

Phthinomita ingramae n. sp. ( Figs. 32–34 )

Type host: Siganus punctatus (Schneider) , Goldspotted Rabbitfish ( 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. punctatus, Lizard Island (QLD), Aug. 2002, Jan. 2003, twenty specimens (Holotype no. QM G 225573 ; Paratype nos. QM G 225574–225579 ) .

Collector: M.J. Nolan.

Etymology

Specific name for Miss Emma J. Ingram, for her continued support and encouragement during the writing of this paper.

Description

Based on 20 whole mounts. With features of genus. Body slightly notched at male genital pore. Anterior testis originating posterior to intercaecal field, but antero­sinistral to distal termination of right posterior caecum, margins lobed. Posterior testis ovoid to spherical. Cirrus­sac tear­shaped. Internal seminal vesicle spherical, occupying ventral region of cirrus­sac; ejaculatory duct sinuous; prostatic cells not seen. Ovary obovate, posterior to posterior margin of anterior testis. Oviduct originating at centre of posterior margin of ovary, passing posteriorly dorsally, entering oötype postero­dorsally. Vitelline duct forming anterior to anterior margin of cirrus­sac, passing posteriorly sinuously, dextral to cirrus­sac, convoluted distally, entering oötype postero­dextrally. Oötype ovate. Mehlis’ gland extending anteriorly to posterior margin of cirrus­sac, extending posteriorly to anterior margin of posterior testis. Uterus extending from oötype, ventral to oviduct. Uterine chamber forming laterally to posterior margin of ovary, straight, narrowing posteriorly, passing dorsally to female genital pore. Vitelline follicles extending anteriorly past intestinal bifurcation, extending posteriorly to posterior margin of uterine chamber, filling intercaecal field, ventral to ovary, oviduct and uterus.

Remarks

This species shows close affinity with the characters differentially diagnostic of the genus Phthinomita and is here identified as a new species in that genus. Phthinomita ingramae n. sp. is immediately distinguished by the combined possession of a body 2317–2983 (2645) long, an anterior testis that is positioned posterior to the intercaecal field but antero­sinistral to the distal termination of the right posterior caecum, an anterior testis 5.4–11.3 times longer than wide and 4.9–10.7 times longer than the posterior testis, a tear­shaped cirrus­sac and a uterine chamber that is 174 long on average.

There are in addition, 10–38 base differences (2.8–11.7% sequence divergence) between the ITS2 rDNA sequence of P. ingramae and the remaining Phthinomita species sequenced here. Sequences from Phthinomita ingramae (three replicates) from S. punctatus off Lizard Island differ by 10 bases from those of Phthinomita sp. A (two replicates) from S. virgatus of Ningaloo Reef.

Figures

FIGURES 32–34. Phthinomita ingramae n. sp. from the intertrabecular spaces of ventricle (heart) of Siganus punctatus off Lizard Island. 32. Adult. Lateral view, whole mount. 33. Male terminal genitalia, lateral view. 34. Female terminal genitalia, lateral view. Scale­bars: 32,34, 250 m; 33, 100 m.