Dendrobaena illyrica ( Cognetti, 1906 )

Dendrobaena illyrica ( Cognetti, 1906) View in CoL

( Figure 1a View FIGURE 1 )

Helodrilus (Dendrobaena) illyricus Cognetti de Martiis, 1906: 1 View in CoL .

Dendrobaena illyrica var. hintzei Ude, 1929: 122 .

Lumbricus bohemicus (anom.) Černosvitov, 1931: 201.

Dendrobaena illyrica hintzei Černosvitov, 1935: 47 .

Dendrobaena illyrica Omodeo, 1956: 174 View in CoL ; Zicsi, 1982: 430; Mršić, 1991: 600; Csuzdi, 2012: 97–99; Stojanović-Petrović et al. 2020: 153.

Material examined. CEKUS/2563 , CEKUS/2564 , CEKUS/2565 , CEKUS/2566 , 4 exp., Serbia, Kopaonik Mt. (Barska reka), 43.30 N 20.74 E, river bank, F. Popović, 30.05.2019 GoogleMaps . CEKUS/2567 , CEKUS/2568 2 exp., Serbia, Kopaonik Mt. (Kuršumlijska Banja), 43.25 N 20.69E, oak forest, F. Popović, 04.05.2021 GoogleMaps .

Morphological description. External morphology. Body pigmentation red violet in live specimens. Red violet homogeneous color in fixed specimens. Length 27–74 mm (Mršić 18–73 mm; Stojanović-Petrović et al. 30– 72 mm) diameter 2–3.5 mm. Number of segments 91–116 (Mršić 76–112; Stojanović-Petrović et al. 94–112). The prostomium is epilobous 1/3 to tanylobous. First dorsal pore at intersegmental groove 5/6. The male aperture is clearly visible on the 15. segment. The female pores in 14 over setae b. The setae are widely paired. The spermathophores are situated on segments 23/24, 24/25, 25, 27, 29, 29/30, 30 lie near b or between aa or near a or between bc setal line. Clitellum saddle-shaped in segments 28, 29–34 (Cognetti 28–34, 35; Zicsi 28, 29–34; Mršić 26, 27, 28, 29–33, 34, 35; Stojanović-Petrović et al. 28, 29–34). Tubercula pubertatis in segments 31–33, ½ 34 (Cognetti 31–33; Zicsi 31–33, ½ 34; Mršić ½30, 31–32, 33, ½34; Stojanović-Petrović et al. 31–32, 33, ½34).

Internal anatomy. Hearts in segments 7–11. Calciferous glands and lateral tubercles are situated in the 11. and 12. segments. Crop in segments 15–16, gizzard in segments 17–18. Three pairs of seminal vesicles in the 9, 11, and 12. segments. Two pairs of spermathecae in segments 9 and 10 segments on the septa 9/10 and 10/11. The testes are in the 10 and 11 segments in the perioesophageal testis sacs. The nephridial bladders sausage-shaped (club-shaped). The typhlosole is club-shaped, rarely tongue-shaped. The longitudinal muscle is pennate.

Remarks. Dendrobaena illyrica was described from Austria ( Cognetti 1906) as Helodrilus (Dendrobaena) illyrica and has subsequently been reported throughout Central and Southern Europe. This species exhibits high variability in pigmentation, the position of the first dorsal pore, the position of the clitellum and tubercula pubertatis, the position of the calciferous glands, and the position of the spermathecae. It is a rare opportunity to find a specimen of D. illyrica that matches the first description. These morphological characters show a high degree of homoplasy within the genus.

Also, the zoogeographic type of this species is questionable. Stojanović et al. (2018) considered that the main center of distribution of the species D. illyrica is in the western Balkans (Illyrian distribution). However, species D. illyrica has been found in the Austria, Bosnia & Herzegovina, Croatia, Czech Republic, Germany, Montenegro and Serbia ( Mršić 1991; Hackenberger Kutuzović & Hackenberger Kutuzović 2013; Lehmitz et al. 2014; Stojanović et al. 2018; Höser 2020; Sekulić et al. 2022). The species has never been recorded in Albania, Greece, Hungary, North Macedonia, Romania Slovakia and Slovenia. Dendrobaena illyrica now appears to have a somewhat disjunct distribution comprising Central European ( Austria, Czech Republic and Germany) and Illyrian ( Bosnia & Herzegovina, Croatia, Montenegro and Serbia) types ( Fig. 2 View FIGURE 2 ). According to Sekulić et al. (2021), the southernmost border of the distribution of D. illyrica is the Šar Mountains. Considering all the facts mentioned for D. illyrica , it can be assumed that the Western Balkans (Northern Dinarides) area is the center of origin and distribution.