Placobdella costata ( Müller, 1774 )

Šatkauskienė, Ingrida & Rutkauskaitė-Sucilienė, Jurgita, 2022, The present state of the leech fauna (Annelida: Hirudinea) in Lithuania, Zootaxa 5115 (1), pp. 47-62 : 51

Placobdella costata ( Müller, 1774)

( Figure 2D )

Material examined. Molėtai (Nr. 4), n=3, 8.viii.2019; Šilalė (Nr. 8), n=3, 5.vii.2018; Mūšia (Nr. 14), n=1, 18.vi.2018; Šventoji (Nr. 20), n=3, 7.viii.2018; Baltieji Lakajai (Nr. 22), n=2, 5.viii.2018; Rudesėlis (Nr. 24), n=1, 6.viii. 2018; Tauragnai (Nr. 31), n=1, 27.vi. 2019; Ilgis (Nr. 33), n=2, 21.viii.2018.

Diagnosis. Body flat, leaf–shape. 40 mm maximum length, and 10–12 mm width. Brown or brownish-green body. From the first glance only one pair of eyespots is visible, since the second pair of eyespots is smaller and lie very close to the first eyespots. Dorsal surface with five longitudinal rows of large white pointed papillae. The bright dotted median wide band, containing bumps and blurry interrupted brown lines (made of 3 dashes) runs along the body ( Fig. 2D ) ( Farzali and Saglam 2020).

Habitat. This species occurs in stagnant water (ponds, lakes) and in rivers ( Table 1 ). Usually, these leeches were found attached to submerged underside of stones and various objects.

Distribution. Placobdella costata is widely distributed over Eastern and Central Europe and North of Africa ( Neubert and Nesemann 1999; Kvist et al., 2022; Romero et al. 2014). The high genetic distance between samples assigned to of P. costata across its distribution, suggests that at least five populations may represent separate species ( Kvist et al. 2022); and probably, samples from Lithuania may be closely related to the lineage C4 which includes samples from Germany and Latvia (see Kvist et al. 2022). The finding of this species in Lithuania was mentioned by Sawyer (1986), Zettler and Daunys (2007), and Bielecki et al. (2012). In the current study, the main localities of P. costata were established in eastern part of Lithuania ( Table 1 ).

Figures

FIGURE 2. Freshwater leeches in Lithuania: ventral view of Alboglossiphonia heteroclita specimen with eggs (A) and dorsal view of the head region (B). Dorsal view of the head region of Hemiclepsis marginata (C). Dorsal view of Placobdella costata whole specimen (D). Dorsal view of Glossiphonia complanata whole specimen (E) and dorsal view of the head (F).