Anonymus ruber n. sp.

(Figs. 4 and 11 F)

Material type. 3 individuals captured, one designed as holotype. The other two specimens were treated histologically, but unfortunately damaged during the process.

Holotype. One specimen captured in Punta de Teno (15/06/2015), north of Tenerife, Canary Islands (Fig. 1, T8; Table 1 and 2) by Leopoldo Moro and Daniel Cuadrado. 78 slides of sagittal serial sectioned specimen and stained with AZAN; Catalogue number: MNCN 4.01 / 1609-1687.

Type locality. Punta de Teno, Tenerife Island, Canary Archipelago, rocky substrate, at depths of 5–8 metres.

Etymology. The name refers to its red colour, rubrum in Latin, therefore Anonymus ruber .

Occurrence in the Canary Islands. The individuals were captured from a rocky substrate exposed to abundant sunlight, at depths of 5–8 metres.

Description. Body shape oval. Length 1–3 cm. Smooth dorsal surface. Dorsal coloration garnet or red, a marginal band with a clear, almost transparent, tonality (Fig. 4 A). Ventral sucker central. Without pseudotentacles, tentacles or extensions on the anterior margin. Marginal eyes are around the entire body edge and two elongated clusters of 100–130 cerebral eyes (Fig. 4 C). Central ruffled pharynx, oral pore central of the pharynx.

Reproductive system: male reproductive system with multiple copulatory apparatus (41 in the holotype, 50 in the other two studied specimens) surrounding both sides of the pharynx and the female gonopore (Fig. 4 C), seemingly random distributed on the body periphery. The male organs are ventral orientated; the seminal vesicles are connected by the vas deferens (Fig. 4 D) and the small penis papilla lack stylet or sclerotic structures (Fig. 4 B and D). In the studied specimens, the male organs are more abundant on the right half of the body.

The female copulatory apparatus has a short vagina, posteriorly oriented, and immersed in a shell and cement glands mass.

Discussion. The genus Anonymus Lang, 1884, is characterized by the presence of multiple male gonopores and multiple male copulatory organs distributed along the longitudinal body axis, surrounding the ruffled pharynx and the female gonopore. The genus comprises three species, Anonymus virilis Lang, 1884, from the Mediterranean Sea, and Anonymus multivirilis Holleman, 1998 and Anonymus kaikourensis Holleman, 1998, from New Zealand.

Anonymus ruber n. sp., from the Canary Archipelago, differs from other Anonymus species due to its opaque garnet colouration compared with the translucent cream pigmentation of A. virilis, the light apricot of A. multivirilis and the dark brown colouration and orange margin of A. kaikourensis . In addition, these species differ in the number of male copulatory organs (Holleman 1998): the holotype of A. ruber has 41 male organs, whereas A. virilis has 20, A. mulivirilis 226 and A. kaikourensis approximately 30 male organs.