Dina orientalis, Grosser, Clemens, Nesemann, Hasko F. & Ć, Vladimir Peši, 2011

Grosser, Clemens, Nesemann, Hasko F. & Ć, Vladimir Peši, 2011, Dina orientalis sp. nov. — an overlooked new leech (Annelida: Hirudinea: Erpobdellidae) species from the Near and Middle East, Zootaxa 2746, pp. 20-24 : 21-24

publication ID	https://doi.org/ 10.5281/zenodo.206857
DOI	https://doi.org/10.5281/zenodo.6182682
persistent identifier	https://treatment.plazi.org/id/038D2C13-9E1D-FFA4-FF24-4B69CC93FF6D
treatment provided by	Plazi
scientific name	Dina orientalis
status	sp. nov.

Treatment

Dina orientalis sp. nov.

Type material. Holotype, Lebanon, Baalbek, 0 6.07.1980, leg. Exped. R. Kinzelbach. Paratypes: 10 specimens, same data as the holotype. The type material is deposited in the Senckenberg Museum Frankfurt (Holotype: SMF 19359; Paratypes: SMF 3742).

Type locality. Lebanon, Baalbek.

Other material. Syria: SMF 3743, road Damascus-Beirut, Nahr Barada, 0 7.07.1980, leg. Expedition Kinzelbach, R., 1 specimen; Turkey: SMF 8767, Aployont, 0 8.08.1984, leg. Expedition Kinzelbach, R., 3 specimen; Israel: SMF, 8768 Jerusalem, Lifra Spring, 0 5.10.1990, leg. Bromley & Nesemann, 15 specimens; Iran: Markazi Province, Aman Abad spring 12 km from Arak (in Arak to Khomein road), 22.07.2003, leg. Pešiċ, 1 specimen, coll. C. Grosser.

Diagnosis. Leeches of medium size with a typical Dina -annulation; the dorsal surface with numerous yellow spots, one wide and bright central longitudinal strip and two dark paramedian stripes; genital pores are separated by two annuli (male in furrow b2/a2, female in furrow b5/b6); the cornua of the atrium are short and curved; the ovisacs are short and strongly coiled in the caudal part, reaching up to the end of the second somite behind the female genital pore or approximately up to annulus b2 of the third somite, the ovisacks are enlarged from the second ganglion behind the female genital pore; the testes begin in the sixth (ca. annuli a2 to b6) or seventh (ca. on the level of furrow b1/b2) somite behind the female genital pore.

Description. Medium sized leeches. Preserved and contracted adults reach a body length of 47 mm (holotype). The body is slightly dorso-ventrally flattened ( Fig. 1 A, B View FIGURE 1 A – E ). The dorsal part of the oral sucker is slightly elongated ( Fig. 2 A View FIGURE 2 A – D ). The annulation is heteronomous and typical for the genus Dina . Four annuli of the quinque-annulate somites are equally wide and annulus b6 is slightly broadened and only rarely subdivided into c11/c12. The other annuli are not subdivided (holotype). Some individuals show a higher tendency to split the annuli. The Syrian specimen has, in the most of somites, a subdivision of each annulus. Genital pores are separated by 2 to 2.5 annuli. The male genital pore in furrow b2/a2, the female in b5/b6, sometimes shifted to the middle of annulus b6 ( Fig. 2 C View FIGURE 2 A – D ).

The information on colour is based on the study of freshly collected material by Nesemann and was published in Nesemann (1993) and Nesemann & Neubert (1999). The colour of the material, preserved for several years, was not or was only partly visible during the examination for this description. The colour of living specimens varies from black and brownish to greenish. The anterior body region and the caudal sucker are brighter. Mid-dorsally, there is one distinctive and wide bright stripe, accompanied by a pair of dark paramedian stripes; sometimes, the bright stripe has an additional central dark line ( Fig. 1 A View FIGURE 1 A – E ). Each annulus bears a transverse row of bright yellowish spots ( Nesemann 1993, Nesemann & Neubert 1999). Spots are numerous (in the middle 12 – 17) on annuli a2 and b5 and rarer on b6 ( Fig. 2 B View FIGURE 2 A – D ). Papillae on the dorsal surface, corresponding with the yellowish spots, are very small.

The genital atrium of the holotype has short cornua reaching the border of the somite ahead (approximately to the furrow b6/b1). The cornua are strongly curved in the ventral direction, with slightly coiled ends and basally strongly thickened ( Fig. 1 C–D View FIGURE 1 A – E ). The vas deferens is thickened from the fourth (rarely third, in the specimen from Syria) ganglia behind the female genital pore and extending to the next six ganglia. The testes begin in the sixth (ca. annuli a2 to b6) or seventh (ca. on the level of furrow b1/b2, in the holotype) somite behind the female genital pore ( Fig. 2 D View FIGURE 2 A – D ).

The ovisacs are short and strongly coiled in the caudal part, reaching up to the end of the second somite behind the female genital pore or up to ca. annulus b2 of the third somite (in the holotype and specimens from Turkey). The ovisacs are thickened from the second ganglion behind the female genital pore ( Fig. 2 D View FIGURE 2 A – D ).

Variability. We found considerable variability in the shape of the atrium and cornua. The Iranian specimen has a genital atrium with only slightly curved cornua, and the ends are not ventrally coiled ( Fig. 1 E View FIGURE 1 A – E ). The specimen from Israel has the genital atrium very similar to that of the Iranian specimen; the specimen from Turkey lack coiled ends too. The specimen from Syria has cornua ventrally strongly curved, similar to that of the holotype, but without coiled ends.

Differential diagnosis. Due to the dark colour with bright yellowish spots, Dina orientalis sp. nov. is similar to Dina stschegolewi ( Lukin & Epshtein, 1960) , D. apathyi Gedroyċ, 1916 , D. punctata punctata Johansson, 1927 , D. punctata maroccana Nesemann & Neubert, 1994 and D. pseudotrocheta Grosser & Eiseler, 2008 . On the other hand, because of the presence of the mid-dorsal bright longitudinal stripe, additional to the spots, the new species resembles Dina minuoculata Grosser, Moritz & Pešiċ, 2007 , D. punctata mauchi Nesemann, 1995 and D. latestriata Neubert & Nesemann, 1995 . Dina orientalis sp. nov. differs from the all aforementioned species, by its internal anatomy. Dina stschegolewi , D. apathyi and D. pseudotrocheta have a genital atrium with long cornua, reaching almost to the previous ganglion, and long, unwinded ovisacs ( Lukin 1976, Grosser & Eiseler 2008). Dina punctata punctata , D. p. maroccana , D. p. mauchi and D. minuoculata resemble D. orientalis sp. nov., due to the presence of atrium with short cornua, but differs in the shape of the ovisacs which are longer, extending four to five ganglia behind the female genital pore, and the ovisacs are not winded ( Grosser et al. 2007, Grosser & Eiseler 2008). Dina latestriata has an atrium, which is very similar to that of Dina orientalis sp. nov.; both species are similar in the presence of short and winded ovisacs, but the ovisacs of D. latestriata are approximately for one somite longer. Furthermore, D. latestriata differs from Dina orientalis sp. nov. in the position of the male genital pore: in D. latestriata the male genital pore is situated in furrow b1/b2, and the genital pores in both sexes are separated by three annuli ( Neubert & Nesemann 1995).

The internal anatomy (i.e., the shape of the ovisacs and vasa deferentia) of Dina orientalis sp. nov. is very similar to D. lineata ( O. F. Müller, 1774) . However, from the latter species and its subspecies (dinarica Sket, 1968, montana Sket, 1968 and concolor (Annandale, 1913)), as well as from Dina farsa Grosser & Pešiċ, 2008 (see: Grosser & Pešiċ 2008), D. orientalis sp. nov. can easily be distinguished by the presence of the bright yellowish spots

Etymology. Dina orientalis sp. nov. is named from its distribution in the Near and Middle East.

Habitat. This species inhabits lotic freshwater; it was mainly found in mountain ranges. Distribution. At present known from Turkey, Iran, Israel, Syria and Lebanon; all former records of D. stschegolewi from the Western Palaearctis are questionable.