Scherotheca qiui Marchán, Decäens & Domínguez, 2023

Marchán, Daniel Fernández, Domínguez, Jorge, Hedde, Mickaël & Decaëns, Thibaud, 2023, The cradle of giants: insights into the origin of Scherotheca Bouché, 1972 (Lumbricidae, Crassiclitellata) with the descriptions of eight new species from Corsica, France, Zoosystema 45 (3), pp. 107-128 : 117

Scherotheca qiui Marchán, Decäens & Domínguez , n. sp.

( Fig. 3E )

urn:lsid:zoobank.org:act:78F07B1F-8F87-4BC8-A454-5E7E3096EC24

TYPE MATERIAL. — Holotype. Corsica • Adult; Corse du Sud, Zonza ; 41°44’34”N, 9°11’42”E; 785 m a.s.l.; 4.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0235 ; MNHN .

Paratypes. Corsica • 1 juvenile specimen; Corse du Sud, Olivese (D69 road) ; 41°50’13”N, 9°5’45”E; 1178 m a.s.l.; 6.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0273 ; MNHN • 2 adult specimens; Corse du Sud, Zicavo, Ponte di Valpine ; 41°52’33”N, 9°7’58”E; 1248 m a.s.l.; 3.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0441, DFM-0442; MNHN • 3 adult specimens; Corse du Sud , Zonza; 41°44’34”N, 9°11’42”E; 785 m a.s.l.; 4.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0230, DFM-0232, DFM-0233; Eco&Sols • 4 adult specimens, 1 juvenile specimen; same data as for preceding; BOLD Sample ID: DFM-0234, DFM-0236, DFM-0237, DFM-0238, DFM-0248; MNHN • 4 adult specimens, 7 juvenile specimens; Corse du Sud, Zonza , Pacciunituli (D368 road); 41°43’26”N, 9°12’10”E; 940 m a.s.l.; 4.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0159, DFM-0160, DFM-0161, DFM-0162, DFM-0163, DFM-0164, DFM-0165, DFM-0166, DFM-0167, DFM-0168, DFM-0169; MNHN • 2 adult specimens; Corse du Sud, Zonza , Pacciunituli (D67 road); 41°44’9”N, 9°10’51”E; 813 m a.s.l.; 03.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0434, DFM-0435; MNHN • 5 adult specimens; Corse du Sud, Zonza , Samulaghia; 41°45’43”N, 9°13’8”E; 975 m a.s.l.; 4.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0483, DFM-0484, DFM-0485, DFM-0486, DFM-0487); MNHN .

ETYMOLOGY. — This species is named after Prof. Jianping Qiu, in recognition to its significant contribution to the taxonomic knowledge of the genus Scherotheca .

DIAGNOSIS. — Scherotheca qiui Marchán, Decäens & Domínguez , n. sp. can be distinguished from non-Corsican species of Scherotheca by the shorter and more anterior clitellum. It resembles Scherotheca litoralis Marchán, Decäens & Domínguez , n. sp. and Scherotheca mausoleana Marchán, Decäens & Domínguez , n. sp., from which it differs by the absence of pigmentation, the number of seminal vesicles (2 pairs instead of 4 pairs in its close relatives) and by the shorter tubercula pubertatis (30-33(1 / n 34) instead of 30-34(35) ( Table 1 ; 2 ; Figs 2 ; 3E ).

COI uncorrected average pairwise distances and topology of multilocus molecular phylogenetic trees support the status of Sch. qiui Marchán, Decäens & Domínguez , n. sp. as separate from other morphologically similar species.

DISTRIBUTION AND ECOLOGY. — Scherotheca qiui Marchán, Decäens & Domínguez , n. sp. was found in several localities in the region of Zonza and Zicavo, Corse du Sud ( Figure 4a ), mainly in Pinus laricio forests at moderate elevations (785 to 1248 m), with some individuals found in Fagus sylvatica forests and shrublands.

DESCRIPTION

External morphology

Body unpigmented.White-beige in fixed specimens ( Fig. 3E ). Average length, 74 mm (64-89 mm, n = 13 adults); body cylindrical in cross-section; average number of segments, 138 (119-152, n = 11 adults; 142 segments in the holotype). Average weight (fixed specimens), 0.92 g (0.60-1.4 g, n = 2 adults). Prostomium epilobous, closed. Longitudinal furrows in segments 1 and 2. First dorsal pore in intersegmental furrow (9/10)10/11. Nephridial pores “en solfège” (irregularly distributed). Spermathecal pores at intersegmental furrows 12/13 and 13/ 14 in setal line c. Male pores in segment 15, surrounded by a well-developed porophore. Female pores in segment 14. Clitellum saddle-shaped in segments (26)27- 35(36). Tubercula pubertatis in segments 30-33(1/ n 34). Chaetae small and closely paired. Genital papillae in segments 11-14,16, (26)27, 28, (29)34, 35, 36.

Internal anatomy

Septa 5/6-10/11 thickened and muscular. Hearts in segments 6-11, oesophageal.Calciferous glands in segments 10-14, with diverticula in segment 10. Crop in segments 15-16, gizzard in segments 17-19. Typhlosole pinnate. Male sexual system holandric, testes and funnels (not enclosed in testes sacs, but with sperm present) located ventrally in segments 10 and 11. Two pairs of reniform seminal vesicles in segments 11 and 12, sometimes with one or two pairs of vestigial seminal vesicles in segments 9 and 10. Ovaries and female funnels in segment 13, ovarian receptacles (ovisacs) in segment 14. Two pairs of small globular spermathecae in segments 12 and 13 (intersegments 12/13, 13/14). Nephridial bladders U-shaped, reclinate in segment 30.

REMARKS

This species corresponds to Sc. corsicana L 2 in the checklist of Corsican earthworms of Marchán et al. (2022a).

Scherotheca quiui n. sp. displayed a level of intraspecific genetic divergence which was slightly above the expected threshold (around 9%), which could indicate the existence of cryptic genetic linages.

Figures

FIG. 3. — External morphology of the newly described species of Corsican Scherotheca Bouché,1972:A, Scherotheca altarocca Marchán,Decäens & Domínguez, n. sp.; B, Scherotheca marceli Marchán, Decäens & Domínguez, n. sp.; C, Scherotheca darioi Marchán, Decäens & Domínguez, n. sp.; D, Scherotheca boccaverghju Marchán, Decäens & Domínguez, n. sp.; E, Scherotheca qiui Marchán, Decäens & Domínguez, n. sp.; F, Scherotheca litoralis Marchán, Decäens & Domínguez, n. sp.; G, Scherotheca capcorsana Marchán, Decäens & Domínguez, n. sp.; H, Scherotheca mausoleana Marchán, Decäens & Domínguez, n. sp. Left side, lateral view; right side, ventral view. Scale bars: 1 cm.

FIG. 2. — External and internal morphological differences between the newly described species of Corsican Scherotheca Bouché,1972 and their closest relatives. The three different shades represent absent, slight and moderate pigmentation. Open circles represent structures that only appear in some individuals. Structures shown in light and dark shades (genital papillae, clitellum and tubercula pubertatis) represent the maximum and minimum extension of these characters, respectively. Phylogenetic relationships are the same as those shown in Figure 1.

FIG. 4. — Distribution of the genus Scherotheca Bouché, 1972 in Corsica: A, localities documented in this work of the newly described species and other Scherotheca species sampled during this work; B, distribution of Corsican species of Scherotheca and Eumenescolex Qiu & Bouché, 1998 according to Bouché (1972), Qiu & Bouché (1998) and Szederjesi et al. (2021).