Trigonostomum penicillatum (Schmidt, 1857) Micoletzky 1910

Trigonostomum penicillatum (Schmidt, 1857) Micoletzky, 1910

(Figs. 2 A–2B)

syn. Vortex penicillatus Schmidt, 1857

syn. Hyporhynchus penicillatus Diesing, 1862 syn. Trigonostomum intermedium nomen nudum Graff, 1910 syn. Trigonostomum marki Graff, 1911

New locality. Rota, Provincia de Cádiz, Spain (36°38’09”N, 6°23’50”W). Los Corrales: small algae in intertidal pools on a rocky cape (11/04/2008).

Known distribution. Northeast Atlantic: European Atlantic coast; Mediterranean Sea; Northwest Atlantic: North American Atlantic coast (see Willems et al. 2004 for a complete overview).

Material. Observations on a live animal. One whole mount.

Remarks. The studied specimen undoubtedly belongs to the taxon Trigonostomum Schmidt, 1852 when considering the construction of the stylet and the bursal appendage. It can easily be recognized as Trigonostomum penicillatum (Schmidt, 1857) Micoletzky, 1910 because the stylet is proximally bent over 90° (Fig. 2 A) and the bursal appendage has a proximal barrel-like casing and a number of tubules, diverging distally (Fig. 2 B) (for a review and identification key of all species of Trigonostomum, see Willems et al. 2004). The stylet from the Spanish specimen measures 53 μm (measured axially), while the bursal appendage has a length of 72 μm. Compared to the sizeranges given by Willems et al. (2004) (stylet: 44–53 μm; bursal appendage: 60–70 μm), the stylet and bursal appendage from the Spanish specimen are among the largest found in this species.