Cestoplana rubrocincta ( Grube, 1840 )

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 : 57-58

Cestoplana rubrocincta ( Grube, 1840)

( Fig. 23 )

Orthostomum rubrocinctum Grube, 1840: 51–56 , figs 9, 12; Grube, 1855: 158, pl. 6, fig. 6. — Diesing, 1850: 238.

Typhlolepta rubrocincta Stimpson, 1857: 3

Cestoplana filiformis Laidlaw, 1903: 110–111 .

Cestoplana australis Haswell, 1907: 479–480 , pl. 37, fig. 5.

Cestoplana rubrocincta Lang 1884: 516–520 , pl. 2, fig. 5.

Material examined: Four specimens, one sagittally sectioned. AM W.51328 (2 slides); AM W.51329, W.53217, W.53222 (wet material). Specimens were collected from Australia, New South Wales: Bottle & Glass, 33°50’53.9”S, 151°16’12.3”E. Coll. Jorge Rodriguez and Justin McNab, October 25 th, 2019 and February 21 st, 2020 , Shelly Beach, Eden , 37°04’22.0”S, 149°54’45.6”E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 10 th, 2018 . Victoria: Harmer’s Haven, Coal Point , 38°39’18.8”S, 145°33’57.1”E. Coll. Jorge Rodriguez, March 27 th, 2019 ; Cape Paterson , 38°40’28.6”S, 145°37’16.5”E. Coll. Jorge Rodriguez, March 25 th, 2019 .

Remarks: Cestoplana rubrocincta is one of the few conspicuous intertidal marine flatworms found in southeastern Australia. This species can be easily identified by its very elongated and slender body shape and its bright orange colouration ( Fig. 23A ). It is commonly found coiled in a ball when hiding under boulders. Internally, C. rubrocincta presents a male copulatory system consisting of a seminal vesicle, interpolated prostatic vesicle and a penis stylet, and a short female system provided with a cement pouch ( Fig. 23B, C ).

Molecular remarks: Cestoplana rubrocincta appeared closely related to another specimen from Phillip Island, Victoria, Australia (100/1.00), and together with another one from Lennox Heads, northern New South Wales, Australia (96/0.58), both sequenced by Litvaitis et al. (2019). This clade is recovered as sister taxa of another containing two specimens from Naples, Italy sequenced by Dittmann et al. (2019) and the Macaronesia ( Cuadrado et al. 2021) (100/1.00). Both clades appear together with high support (100/0.96).

Distribution: Mediterranean Sea ( Grube 1840); Kenya, Africa ( Laidlaw 1903b); Porto de Sal Rei, Boa Vista Island, Cape Verde ( Laidlaw 1906); Japan: Susaki near Simoda ( Kato 1937b), Kanayama ( Kato 1938); Shirahamacho, Cape Bansho Zaki ( Kato 1944); Italy: Naples ( Kato 1944), Island of Sicilia ( Kato 1944); Inca-Inca, Gaira Bay, Colombia ( Quiroga 2008) and Port Jackson, New South Wales, Australia ( Haswell 1907).

Key to southeastern Australian polyclads

1. Tentacles absent...................................................................................... 2 - Tentacles present as nuchal tentacles above the brain area..................................................... 8 - Tentacles present as pseudotentacles in the anterior margin................................................... 12 2. Body shape oval, with eyes in a fan-like pattern..................................... Neostylochus ancorus sp. nov. - Body shape elongated.................................................................................. 3 - Body shape very slender and elongated, worm-like........................................................... 7 3. Dorsal surface with two longitudinal dark brown stripes and dark brown anterior region..... Prosthiostomum amri sp. nov.

- Dorsal surface with inconspicuous colouration.............................................................. 4 4. Background colour cream or light brown, male copulatory organ externally visible as a brown, elongated line behind the pharynx............................................................... Echinoplana celerrima Haswell, 1907 - Background colour cream, male copulatory organ externally inconspicuous....................................... 5 - Background colour grey or brown........................................................................ 6 5. With short stylet.................................................................... Notoplana felis sp. nov. - With very long stylet..................................................... Notoplana longiducta Hyman, 1959 - With penis papilla...................................................... Notocomplana distincta Prudhoe, 1982 6. Pharynx in the middle of the body......................................... Notoplana australis ( Schmarda, 1859) - Pharynx in the posterior half of the body................................ Leptostylochus victoriensis Beveridge, 2017 7. Dorsal surface orange................................................... Cestoplana rubrocincta ( Grube, 1840) - Dorsal surface reddish brown.................................................... Eulatocestus australis sp. nov. 8. Dorsal surface black with orange and white marginal bands..................... Callioplana marginata Stimpson, 1857 - Dorsal surface green.......................................................... Stylochoplana clara Kato, 1937 - Dorsal surface orange yellow with black marginal band........................ Paraplanocera marginata Meyer, 1922 - Dorsal surface cream or light brown...................................................................... 9 9. Body shape circular.................................................................................. 10

Body shape elongated................................................................................. 11 10. Dorsal surface with scattered dark spots.................................. Idioplana australiensis Woodworth, 1898 - Dorsal surface with light reddish colour pattern, more intense above pharynx region... Planocera edmondsi Prudhoe, 1982 11. Tentacles reduced to knobs, dorsal surface with light reddish colour pattern............. Parabolia megae gen. et sp. nov. - Anterior body region expanded, dorsal surface with scattered dark brown spots and cream colouration above the pharynx...

.......................................................................... Ceratoplana falconerae sp. nov. - Dorsal surface with brown spots, intestinal branches externally visible................. Tripylocelis typica Haswell, 1907 12. Dorsal surface white.......................................................... Diposthus popeae Hyman, 1959 - Dorsal surface brown, with papillae.......................................... Thysanozoon brocchii ( Risso, 1818)

Figures

FIGURE 23. Cestoplana rubrocincta (Grube, 1840). A. Dorsal view of live specimens. B. Sagittal reconstruction of the reproductive system. C. Histological sections of the reproductive system.