Scutisotoma karadagi Potapov & Babenko & Fjellberg 2006, sp.n.
Creators: name: Potapov, Mikhail
name: Babenko, Anatoly
name: Fjellberg, Arne
Publisher: name: Zenodo
Year: 2006
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Collembola
Entomobryomorpha
Isotomidae
Scutisotoma
Scutisotoma karadagi

description: Scutisotoma karadagi sp.n.   
Figs. 21, 48–64  
 Type material. Holotype: ♀, Ukraine, Crimea Peninsula, Karadagsky Reserve (44 o 49’N, 34 o 53’E), seacoast under Beregovoi Range, on cliff moistened with spring, 28.vi.1994, leg. M. Potapov. Paratypes: 20 exx., same sample (MSPU).   
 Other material. 10 exx., type locality, collected July 1996, leg. N. Kuznetsova. 7 exx., Russia, NW Caucasus, Krasnodarsky Krai, seacoast between Dzankhot and Divnomorskoye, wet calcareous rocks near spring, June 2001, leg. M. Potapov. 8 exx., Iraq, Mahmudia, in bog in ditch with reed-like plant, April 1978, leg. W. M. Weiner (4 exx.: ISEA, 4 exx.: MSPU).   
 Description. Size 1.1–1.5 mm, males and females of similar size. Colour dark-violet (specimens from Iraq paler, grey-violet), extremities clearly paler. Cuticle on last abdominal segments slightly rugose, ecomorphic specimen with conical cuticular papillae on Abd.V has been seen (Fig. 63). Ocelli 8+8, G and H smaller (Fig. 53). PAO elliptical, not constricted, about twice as long as ocellus or 0.4–0.7 as long as inner unguis. Maxillary outer lobe with 4 sublobal hairs, maxillary palp bifurcate, maxillary head as on Fig. 21. Labral formula 4/554. Labium with a complete set of papillae and guards, 3 proximal and 4–5 basomedian chaetae (often asymmetrically 4+5). Ventral side of a head usually with 5+5 postlabial chaetae. Ant.1 with 2 basal microsensilla (bms), dorsal and ventral, and 2 ventral sensilla (s). Ant.2 with 3 bms and one laterodistal s. Ant.3 with one bms and 5 distal s (including 1 lateral), adult males have additional sensilla in the middle part of Ant.2–3. Sensilla on Ant.4 poorly differentiated, subapical organite minute.   
Tergal sensilla well differentiated, shorter than ordinary chaetae. Sensillar formula 33/ 22224 (s), 11/111 (ms) (Fig. 59). The position of the most lateral sensillum on Th.II varies but is always posterior to other sensilla of the lateral group (Figs. 60–62). Medial sensilla on Abd.III set in front of the p-row, in posterior 1/4–1/3 of the tergite. The Abd.V sensilla set in a square pattern (Fig. 58). Macrochaetae poorly differentiated, only developed on Abd.V–VI, medial macrochaetae on Abd.V are 0.2–0.3 as long as the tergite. Axial chaetom of Th.II–Abd.III as 9–10,7–8/5–6,6,6–8. Th.III with more than 30 chaetae in the p-row. Thorax without ventral axial chaetae.  
 Unguis rather elongated, without inner tooth (Figs. 54–55). Tibiotarsi 1–3 with more than 21-21-25 chaetae, B-row complete. Tibiotarsal tenent chaetae (1-2-2) clearly clavate, slightly shorter than unguis (U 3: t.ch. = 1,1–1,5: 1). Chaetae x and B 5 on Ti. 3 in males long and thick, sometimes bifurcate at apex (Fig. 55). Ventral tube with 5(4)+5(4) laterodistal and only two posterior chaetae (Fig. 64). Tenaculum with 4+4 teeth and one chaeta (Fig. 57). Anterior furcal subcoxa with 29–35 chaetae, posterior with 13–15. Anterior side of manubrium with a pair of distal chaetae, posterior side with more than 30+30 chaetae and with additionally 6+6 chaetae on its laterobasal lobes (Fig. 49). Dens with 33–37 anterior chaetae, basal 1/4–1/3 without chaetae. Posterior side of dens tuberculate, with many chaetae arranged in 4 groups (10–12 basal, 6–8 outer; 7 inner, and a single subapical chaeta near mucro (Figs. 49, 52). Mucro strong and lamellate, with 3 subequal teeth (Figs. 50, 51). Ratio of manubrium: dens: mucro = 5.6–7.1: 4.7–6.1: 1. Chaetotaxy of anal lobes as Fig. 56.   
 Affinity. The long furca, tuberculate dens and 3-toothed mucro put the new species rather close to S. ladaki and S. muriphila. From both it is easily distinguished by the position of sensilla on Abd.V and Th.II, the exceptionally small number of posterior chaetae on VT, enlarged male spurs on Ti.3, larger anterobasal portion of dens without chaetae, and the 4+4 teeth on tenaculum.   
 A similarly long furca with the same type of mucro is also known in the Nearctic species “ Proisotoma ” macgillivrayi (Dalla Torre) (New Mexico, Louisiana) which is said to be characterised by fused Abd.V –VI (Christiansen & Bellinger 1998).   
 Apart from the fusion of the last two abdominal segments, which we regard as a sharp diagnostic character, Rhodanella minos (Denis) shows affinity to the group of longfurcated surface-dwelling species of Scutisotoma (muriphila, ladaki, karadagi, titusi). All these forms are very similar in furcal characters, outer mouth parts, tibiotarsal chaetotaxy, and the microsensillary set on the tergites. A study of 10 specimens of R. minos from Africa, “Zougoussi – R te de Taabo, C ô te d'Ivoire, 6 iv 1994, C.Girard leg.” (MNHN) revealed a strong sensillary polychaetosis, a feature shared only with S. titusi (less pronounced). The mucro and polychaetose sensillary fields on the three last abdominal segments of Rhodanella are shown in Figs. 65–66. None of the Scutisotoma species show a sexual dimorphism like that we see in R. minos.   
 Distribution. Known from Crimea, Caucasus and Iraq. Near and on water, both stagnant and running.   
 Name derivation. The new species is named after the type-locality, Karadag, a volcanic massif on the southern shore of the Crimea Peninsula.
description: Published as part of Potapov, Mikhail, Babenko, Anatoly & Fjellberg, Arne, 2006, Taxonomy of the Proisotoma complex. Redefinition of genera and description of new species of Scutisotoma and Weberacantha (Collembola, Isotomidae), pp. 1-74 in Zootaxa 1382 (1) on pages 24-26, DOI: 10.11646/zootaxa.1382.1.1, http://zenodo.org/record/5071464