Eurylepta cornuta (O.F. Mueller , 1776) Ehrenberg, 1831

Norena, Carolina, Marquina, Daniel, Perez, Jacinto & Almon, Bruno, 2014, First records of Cotylea (Polycladida, Platyhelminthes) for the Atlantic coast of the Iberian Peninsula, ZooKeys 404, pp. 1-22 : 4

Eurylepta cornuta (O.F. Mueller, 1776) Ehrenberg, 1831 Figure 2

Material examined.

Two mature specimens captured during winter 2012 (15/01/2012). Voucher: one specimen sectioned sagittally, stained with Azan and deposited in the Invertebrate Collections of the MNCN; Cat. Nr: MNCN 4.01/626 to 4.01/647 (22 slides).

Description.

Captured worms 10 mm long and 5 mm wide. Body shape elongated, with straight margins. Dorsal surface smooth. Background coloration of the dorsal surface pale brown, translucent, with dark branched bands, red or brown, depending on intestinal contents, (Figure 2A). Ventral side pale yellow without bands. With narrow conical marginal tentacles; sucker slightly posterior to the middle of the bodies. Tentacular eyes at the base of the tentacles (Figure 2C) and cerebral eyes in two elongated clusters, sometimes extending over the pharynx. Tubular, whitish pharynx is visible at the anterior end (Figure 2C).

Male copulatory apparatus located posterior to male pore and directed forwards (Figure 2D). Prostatic vesicle oriented antero-dorsally, with a smooth glandular epithelium, and directly connected to tubular stylet of penis papilla. Seminal vesicle empties through a narrow short duct into distal end of prostatic vesicle. Female pore lies closely behind male pore, but is clearly separated. Female atrium elongated. Cement pouch rounded and followed by a short vagina and opening of uteri. A pair of uterine vesicles is present.

Remarks.

Eurylepta cornuta shows two varieties: 1. Eurylepta cornuta var. lobianchi, first described by Lang (1884) and known from the Mediterranean Sea, and 2. Eurylepta cornuta var. melobesiarum, first described by Schmidtlein (1880) as Proceros melobesiarum . The main difference between these varieties is in the arrangement of the cerebral eyes ( Lang 1884; Bock 1913). In Eurylepta cornuta var. melobesiarum the elongated patches are shorter than in Eurylepta cornuta var. lobianchi. Therefore, and in agreement with other authors (e.g., Micoletzky 1910; Bock 1913; Faubel 1984), we consider the difference not enough to maintain the two varieties and propose that should no longer be recognized.

Distribution.

Eurylepta cornuta was found in empty shells of Mytilus galloprovincialis (Figure 2A), which were attached to mussel culture ropes suspended from specially designed rafts called “bateas”, located in La Palmeira (Ria de Arosa, Galicia, Spain) at a depth of 13 metres (42° 34.3910N, 008° 56.6360W). Several specimens of Eurylepta cornuta (Figure 2B) were also captured for the first time within Saccorhiza polyschides stipes (macroalgae), at a depth of 8 metres in "Cuberto Camouco" (Ria de Arosa, Galicia, Spain) (42° 33.4150N, 008° 57.8390W). Another specimen was found under a stone on the island of Rua, at a depth of 14 metres (42° 32.9200N, 008° 56.4220W).

Eurylepta cornuta has been known since the 18th century from Kristiansand, Norway ( O.F. Müller 1776) and since the 19th century from Belfast Bay, Ireland ( Thompson 1845); Saint Malo, France ( Keferstein 1868); Plymouth Sound, United Kingdom ( Gamble 1893); and the Gulf of Naples, Italy ( Lang 1884).