Dina sketi Grosser & Pešić, 2014

Grosser, Clemens, Pešić, Vladimir & Dmitrović, Dejan, 2014, Dina sketi n. sp., a new erpobdellid leech (Hirudinida: Erpobdellidae) from Bosnia and Herzegovina, Zootaxa 3793 (3), pp. 393-397 : 394-395

Dina sketi Grosser & Pešić n. sp.

( Figs. 1 , 2 )

Type material. Holotype ( SMF 19955), Bosnia and Herzegovina, Republic of Srpska, Kotor Varoš, canyon of the Cvrcka river, spring Vilenjska vrela, 44°33.003' N, 17°23.580' E, 456 m asl, 2 December, 2012, leg. Dmitrović, body length 53 mm, width 6 mm. Paratypes ( SMF 19956): one specimen (body length 32 mm, width 5 mm), same locality and data as holotype; three specimens (body length/width: 40/ 5.5 mm, 33/ 5 mm, 18/ 4 mm), same locality as holotype, 2 September, 2012, leg. V. Pešić.

Further record. Bosnia and Herzegovina, Kotor Varoš, canyon of the Cvrcka river, captured spring, 44°33.131' N, 17°24.000' E, 383 m asl, Juny 2013, leg. D. Dmitrović, one specimen, body length 43 mm, width 6 mm.

Etymology. Named after Prof. Boris Sket (Ljubljana, Slovenia) in appreciation of his studies of Balkans leech fauna.

Diagnosis. Leeches with a typical Dina -annulation (quinqueannulate, b1, b2, a2, b5 <b6 (c11, c12)). Dorsal surface in anterior part of body medially with one bright stripe, bordered by two wide and dark greyish areas, in posterior part of body with one dark median and two dark paramedian longitudinal stripes. Papillae and yellow spots absent. Genital pores are separated by two annuli (male in the furrow b2/a2, female in the furrow b5/b6). Atrial cornua narrow. Ovisacs very short reaching up to ca. annulus b1 of the second somite behind the female genital pore, and curled in posterior part of ovisac course.

Description. Habitus: Preserved specimens up to 50 mm long and 6 mm wide. The anterior part of the body is cylindrical; posteriorly, the body is flattened with the lateral keels shifted to the last quarter of the body ( Fig. 1 B). The caudal sucker is slightly narrower than the maximum body width ( Fig. 1 A). The dorsal and ventral surface is smooth, without papillae. The mouth is wide; the upper lip of the oral sucker not elongated ( Fig. 1 C).

Eyes: The visible eyes are reduced. The holotype possesses one eye; one paratype are with four indistinctly visible eyes, the other paratypes possess up to five indistinct eyes.

Colour: The colour of dorsal surface of preserved specimens is greyish to brownish. The anterior part of the body possesses a medial bright stripe on dorsal surface. It is bordered by two wide and dark greyish areas. The posterior part of the body has one dark median and two dark paramedian longitudinal stripes on the dorsal surface. Sometimes, the paramedian stripes and the median stripe are not clearly distinguished (see Fig. 1 B). Yellow spots are absent ( Fig. 1 A).

Annulation: The midbody somites are basically heteronomously quinqueannulate with annulus b6 broadened, b1, b2, a2, b5 <b6; b6 and sometimes b1 are subdivided by a very shallow furrow ( Fig. 1 D). The genital pores are separated by two annuli; the male gonopore is situated in the furrow b2/a2, the female gonopore in the furrow b5/b6.

Atrium: The atrium has a large body with two narrow cornua ( Fig. 2 B, C), reaching to annulus b1 of the same somite. The cornua bending to the ventral side, forming from frontal view a right angle between each other. The ends of the cornua are sharply coiled.

Vasa deferens: The paired vasa deferentia are thickened from the third ganglion to the sixth ganglion behind the female genital pore; after that begins the part with numerous testes ( Fig. 2 A).

Ovarian sacks: The ovisacs are paired structure which are lying dorsally to the vas deferens. They are very short, reaching up to ca. annulus b1 of the second somite behind the female genital pore, and curled in posterior part of the ovisac course ( Fig. 2 A).

Discussion. Our specimens possessed midbody somites basically heteronomously quinqueannulate with annulus b6 broadened and subdivided by a very shallow furrow, with the resulting annuli c11/c12 of the same width. According to this annulation pattern, the present new species was assigned to the genus Dina . Due to the characteristics of internal anatomy (presence of short and winded ovisacs and similar shape of atrium), Dina sketi n. sp. resembles to D. latestriata Neubert & Nesemann, 1995 , and D. orientalis Grosser, Nesemann & Pešić, 2011 . The former species known from the littoral of Prespa lake in Macedonia differs in its having bright spots on the dorsal surface of each annulus and the more elongated upper lip of the oral sucker (see Neubert & Nesemann 1995, Nesemann & Neubert 1999). Moreover, D. latestriata has its male genital pore in the furrow b1/b2 (b2/a 2 in D. sketi n. sp.) and thus has three annuli between gonopores (two annuli in D. sketi n. sp.). The latter species known from the Near and Middle East can be easily distinguished from the present new species by its possession of bright yellowish spots on the dorsal surface ( Grosser et al. 2011a).

Based on the body coloration, the new species resembles D. l. dinarica and D. farsa Grosser & Pešić, 2008 (South Iran, Grosser & Pešić 2008). However, both species can be easily distinguished from D. sketi n. sp. by the shape of ovisacs, which are curled in their entire course, and in D. l. dinarica one somite longer, in Dina farsa one somite shorter than in Dina sketi n. sp. Additionally, D. l. dinarica has well visible longitudinal paramedian stripes along the entire length of its dorsal surface, while the mid-dorsal stripe with a brighter and darker part is lacking. On the basis of these comparisons we could conclude that Dina sketi n. sp. represent a species new for science.

Habitat. Dina sketi n. sp. were collected in rheocrene springs in deciduous forests dominated by the common beech ( Fagus sylvatica L.).

Figures

FIGURE 1. Dina sketi n. sp.: A = dorsal view, holotype; B = lateral view, paratype; C = mouth opening (left, paratype; right, holotype); D = annulation pattern, holotype.

FIGURE 2. Dina sketi n. sp., holotype. A = internal anatomy (Abbreviations: a, atrium; b, ovarian sacks; c, vas deferens; d, testisacs). B-C = atrium: B = ventral view, C = lateral view, holotype.