Trocheta taunensis, - & Grosser, 2015

- & Grosser, Clemens, 2015, Differentiation of some similar species of the subfamily Trochetinae (Hirudinida: Erpobdellidae), Ecologica Montenegrina 2 (1), pp. 29-41 : 37-40

Trocheta taunensis n. sp.

( Figs. 8 A­E)

Material examined: Holotype ( SMF 19957 ): body length 101 mm, width 6 mm; Germany, Hesse, Taunus Mt., river Wisper between Geroldstein and Kammerburg, 19 April 2000, leg. C. Grosser. Paratypes: 14 specimens, same locality and data as holotype (four paratypes: SMF 19958 ) .

Locus typicus: Germany, Hesse, Taunus Mt., river Wisper between Geroldstein and Kammerburg.

Description

Annulation: Typical Trocheta ­ like annulation. The somites of the holotype are heteronomously subdivided into three broadened (b2, a2, b5) and five narrow (c1, c2, c11, d23, d24) annuli. This annulation correspond to the diagnosis of Trocheta and justify the classification to this genus (Sawyer 1886, Nesemann & Neubert 1999). The male genital pore is in furrow b2/a2 and the female is in furrow b5/c11. The genital pores are separated by two full annuli. Annulus b5 is slightly subdivided ( Fig. 8C). Some paratypes show a high tendency to split annulus b5 into annuli c9 and c10. In these specimens the genital pores are separated by three annuli. Sometimes, annulus a2 is also subdivided. In this case, the male and female pores are separated by four annuli.

Size: Large leeches, preserved specimens up to 114 mm (the largest preserved paratype: body length 114 mm, width 6 mm).

Habitus: The anterior part of the body is cylindrical, the posterior part is slightly flattened. The dorsal surface is convex in their total run. Lateral keels exist, special distinct in the last third of the body. The keels are small and not curved dorsally. The upper lip of the cranial sucker is elongated ( Figs. 8 A­B). The body surface is smooth, only few very small and inconspicuous papillae are visible. Eyes are not visible on the preserved type material.

Colour: The colour of dorsal surface is unicolour greyish to bright reddish brown. Preserved specimens are white to pale grey. Dark lines, stripes or yellow spots are absent.

Sexual organs: The genital atrium is typical Trocheta ­ like with cornua which extends distinct on the previous somite. The genital atrium has long and straight or only horizontally slightly curved cornua. The apical part of the cornua is coiled ( Fig. 8E). The cornua extends to annulus b5 of the previous somite. The broadened part of the vasa deferentia extends to the sixth ganglion after the female genital pore. Here is the start of the testicles. The ovarian sacks extends to the end of the third or slightly on the fourth somite after the female genital pore. They are only few winded in their total run and not curled in posterior parts. The ovisacs run only dorsally and do not cross the vasa deferentia ( Fig. 8D).

Etymology: The species is named after the mountains where the species was found.

Differential diagnosis: The unicolour species Trocheta taunensis n. sp. is similar to T. cylindrica , T. haskonis Grosser, 2000 and T. danastrica Stschegolew, 1938 . T. cylindrica differs from T. taunensis n. sp. by the characteristics of the reproductive system. T. cylindrica has a genital atrium with strong angular curved cornua; the ovarian sacks are one somite shorter and curled in posterior parts ( Figs. 9 A­B).

Trocheta haskonis differs from T. taunensis n. sp. in the shape of the papillae and position of the accessory genital pores. T. haskonis has numerous small but well visible papillae roughen the dorsal and ventral surface, and accessory pores are located left and right of the male genital pore ( Fig. 2 in Grosser 2013). These accessory pores are absent in T. taunensis n. sp.

Trocheta danastrica differs from T. taunensis n. sp. in the body form, and the shape of the papillae and the genital atrium. The body of T. danastrica is longer and more slender, the genital atrium has very long and curved cornua, and the papillae are numerous and well visible ( Figs 1, 6, 8 in Grosser & Epshtein 2009).

Habitat: The Wisper is a small stream, shaded by riparian vegetation, with a width of ca. four to five metres. The fast running water is cold, shallow and stony. The most leeches were found under stones in the moist bank outside the water.

Distribution: The species is only known from the locus typicus. The examination of further finds of “ Trocheta bykowskii ” from Central Europe (e.g. Germany: Eifel or Austria: Vienna Woods; see Nesemann 1993, 1997) will lead to a new records of T. taunensis n. sp.