Paraplanocera marginata Meyer, 1922

Rodríguez, Jorge, Hutchings, Pat A. & Williamson, Jane E., 2021, Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia, Zootaxa 5024 (1), pp. 1-63 : 29-32

Paraplanocera marginata Meyer, 1922

( Fig. 10 )

Paraplanocera marginata Meyer, 1922: 139–145 , pl. 1, figs 1–8, text figs 1–3a; Prudhoe, 1945: 195.

Material examined: One specimen sagittally sectioned. AM W.50277 (16 slides). A specimen was collected from Australia, New South Wales, Toowoon Bay , rocky headland adjacent to SLSC, found under rocks, 33°21’47.01”S, 151°30’7.31”E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, May 16 th, 2018 .

Remarks: The Toowoon Bay specimen agreed with the original species description by Meyer in 1922.Externally, Paraplanocera marginata Meyer, 1922 possesses a rounded body, a pair of nuchal tentacles and an orange yellow dorsal surface with scattered small white dots and a black marginal band with intermittent white streaks ( Fig. 9A ). Internally, the male copulatory system of P. marginata is characterised by the presence of a free prostatic vesicle provided with tubularly chambered glandular epithelium in its proximal region, two oval-shaped seminal vesicles, a cirrus lined with spines that grow larger distally, and the presence of an accessory prostatic vesicle at the distal end of the cirrus bulb. The female system is provided with a bursa copulatrix, cement glands grouped in two pockets, and a long Lang’s vesicle ( Fig. 9B, C ).

Meyer (1922) described the marginal band of P. marginata as purple, while the one in the present specimen appeared black. Prudhoe (1989) notes that an individual of P. marginata from Australia was seen bearing a narrow submarginal black band, which matches that of the studied specimen.

Molecular remarks: Paraplanocera marginata Meyer, 1922 appeared together with another specimen from Hawaii ( USA) sequenced by Litvaitis et al. (2019) with high support (100/1.00). The Paraplanocera clade also appeared as the closest relative to the Planocera clade with high support (99/1.00) in the Planoceridae family.

Distribution: Red Sea ( Meyer 1922, type locality); Kenya, Africa and the Persian Gulf ( Prudhoe 1945); USA, Hawaii ( Litvaitis et al. 2019).

New record: Toowoon Bay, New South Wales ( Australia).

Figures

FIGURE 9. Planocera edmondsi Prudhoe, 1982. A. Dorsal view of the fixed specimen (left), details of the tentacles (centre) and details of the pharynx and reproductive systems (right). B. Sagittal reconstruction of the reproductive system. C. Histological sections of the reproductive system.

FIGURE 10. Paraplanocera marginata Meyer, 1922. A. Dorsal view of the live specimen (left) and details of the tentacles on the fixed specimen. B. Arrangement of the eyes (left), details of the pharynx (centre) and details of the reproductive systems (right). C. Sagittal reconstruction of the reproductive system. D. Histological sections of the reproductive system.