Pseudoceros stimpsoni (Stimpson, 1855)

Marquina, Daniel, Aguado, M. Teresa & Noreña, Carolina, 2015, New records of Cotylea (Polycladida, Platyhelminthes) from Lizard Island, Great Barrier Reef, Australia, with remarks on the distribution of the Pseudoceros Lang, 1884 and Pseudobiceros Faubel, 1984 species of the Indo-Pacific Marine Region, Zootaxa 4019 (1), pp. 354-377 : 361-362

Pseudoceros stimpsoni (Stimpson, 1855)

( Fig. 5 )

Eurylepta interrupta Stimpson, 1855: 380 .

Pseudoceros stimpsoni Newman & Cannon, 1998: 315 –316, figs 12A–C, 16D. Pseudoceros interruptus Kato, 1944: 298 .— Prudhoe 1989: 84, fig. 31.

Material examined. AM W.45205, MI QLD 2448, sagittally sectioned.

Description. Body is oval, 12 mm long, 6 mm wide. Dorsal colour pattern is light brown background, with numerous white speckles of irregular outline and size. In the median line the speckles are bigger, forming a false line; two marginal bands (inner to outer), are orange and white. Orange band is surrounded at both sides by fainter bands of grey or black ( Fig. 5 A). Sucker very close to female pore ( Fig. 5 D, E). Seminal vesicle is small, with strong muscular walls and ventro-dorsally oriented. Prostatic vesicle is big and oval. Prostatic duct is narrow and short. Penis papilla is armed with a conic stylet, inside a very shallow male atrium ( Fig. 5 B, E). Female system ( Fig. 5 C, E) has the configuration characteristic for the genus.

Remarks. Pseudoceros stimpsoni shows the colour pattern comparable with the light brown morphotype of Pseudoceros bicolor Verrill, 1901 ( Litvaitis et al. 2010; Bahia et al. 2014). However, some differences are noticeable between the examined specimen and the light brown morphotype of P. b i c ol o r: first, the orange marginal band is narrow in P. stimpsoni , but wider and diffuse in P. b i c o l o r; although faint, in P. stimpsoni it appears as a black/grey band at both sides of the orange marginal band, while in P. bi color a discontinuous black band appears only external to the orange one; lastly, the interruptive white speckles of the orange band are quite small in P. stimpsoni in comparison to those in P. b i c o l o r. Furthermore, P. stimpsoni occurs in the Indo-Pacific region, while P. bicolor is only known from West Atlantic ( Bermuda ( Verrill 1901), Curaçao ( Marcus & Marcus 1968; Litvaitis et al. 2010), Caribbean coast of Colombia ( Quiroga et al. 2004b), Belize, Florida, Honduras, Jamaica, Panamá ( Litvaitis et al. 2010), and Brazil ( Bahia et al. 2014)). However, future DNA analysis should be conducted in order to confirm or reject the synonymisation of these two species.

Distribution. Previously found in Ryukyu Islands, Japan ( Kato 1944), Nagada Harbour, Papua New Guinea ( Newman & Cannon 1998) and Mozambique ( Prudhoe 1989). First report for Lizard Island and Australia.

Figures

FIGURE 5. Pseudoceros stimpsoni Newman & Cannon, 1998, AM W. 45205, MI QLD 2448. A. Live specimen; B – D. Histological sections of the reproductive system; E. Sagittal reconstruction of the reproductive system. Anterior to the left in B – E. Abbreviations: cg = cement glands, cp = cement pouch, fp = female pore, i = intestine, ma = male atrium, p = pharynx, pv = prostatic vesicle, s = stylet, spv = spermiducal vesicles, su = sucker, sv = seminal vesicle, uv = uterine vesicles, va = vagina.