Scherotheca altarocca 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 : 111-114

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

( Fig. 3A )

urn:lsid:zoobank.org:act:89EFE242-73AF-435E-86C8-67B17B93D253

TYPE MATERIAL. — Holotype. Corsica • Adult; Corse du Sud, Zicavo, Castellu d’Ornucciu ; 41°52’22”N, 9°9’17”E; 1422 m a.s.l.; 3.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0446 ; MNHN.

Paratypes. Corsica • 3 adult specimens; Corse du Sud, Olivese (D26 road); 41°50’45”N, 9°4’55”E; 1051 m a.s.l.; 6.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0512, DFM-0513, DFM-0514; MNHN • 3 adult specimens; 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.; Eco&Sols; BOLD Sample ID: DFM-0266, DFM-0267, DFM-0268 ) • 2 adult specimens, 12 juvenile; same data as for preceding; BOLD Sample ID: DFM-0269, DFM-0270, DFM-0271, DFM-0272, DFM-0274, DFM-0275, DFM-0276, DFM-0277, DFM-0278, DFM-0279, DFM-0280, DFM-0281, DFM-0282, DFM-0283; MNHN • 6 adult specimens; Corse du Sud, Zicavo, Castellu d’Ornucciu ; 41°52’22”N, 9°9’17”E; 1422 m a.s.l.; 3.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID: DFM-0447, DFM-0448, DFM-0449, DFM-0450, DFM-0451, DFM-0452; MNHN • 3 adult specimens; Corse du Sud, Zicavo, Ponte di Valpine ; 41°52’33”N, 9°7’58”E; 1248 m a.s.l.; 03.IV.2021; T. Decaëns, D. Fernández Marchán leg.; BOLD Sample ID:, DFM-0443, DFM-0444, DFM-0445; MNHN .

ETYMOLOGY. — The species name is derived from the natural region of Altarocca where the type specimens have been collected (name in apposition).

DIAGNOSIS. — Scherotheca altarocca Marchán, Decäens & Domínguez , n. sp. can be distinguished from all of the other species of Scherotheca (except Sc. corsicana popi Qiu & Bouché, 1998 ) by the position of the clitellum in segments (29)30-36(37) and tubercula pubertatis in segments (½ 32)33-36(37) ( Tables 1 ; 2 ; Figs 2 ; 3A ). Although Sc. altarocca Marchán, Decäens & Domínguez , n. sp. resembles Scherotheca corsicana popi Qiu & Bouché, 1998 in characters such as the clitellum and tubercula pubertatis, it does not exactly fit the description made by Qiu & Bouché (1998a), differing significantly in internal characters such as position of spermathecae and number of seminal vesicles (spermathecae in (11)12, 13 vs 13, 14 and 2 pairs of seminal vesicles in Sc. altarocca Marchán, Decäens & Domínguez , n. sp. vs 4 pairs in Sc. corsicana popi ).

COI uncorrected average pairwise distances and topology of multilocus molecular phylogenetic trees supports the status of Sc. altarocca Marchán, Decäens & Domínguez , n. sp. as independent from other morphologically related species for which sequences are available.

DISTRIBUTION AND ECOLOGY. — Scherotheca altarocca Marchán, Decäens & Domínguez , n. sp. has been found in the municipality of Olivese and Zicavo, in the natural region of Altarocca, Corse du Sud ( Fig. 4A ), in Fagus sylvatica L. forests and alpine grasslands at moderately high elevations (1051 to 1258 m).

DESCRIPTION

External morphology

Body pigmentation absent. White-beige in fixed specimens ( Fig. 3A ). Average length, 80 mm (66-95 mm, n = 12 adults); body cylindrical in cross-section; average number of segments 149 (135-156 mm, n = 11 adults; 135 segments in the holotype). Average weight (fixed specimens), 1.26 g (0.81-1.78 g, n = 14 adults). Prostomium epilobous, closed. Longitudinal furrows in segments 1 and 2. First dorsal pore at intersegmental furrow 10/11. Nephridial pores “en solfège” (irregularly distributed). Spermathecal pores at intersegmental furrows (11/12) 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 (29)30-36(37). Tubercula pubertatis in segments (½ 32)33-36(37). Chaetae small and closely paired. Genital papillae in segments (10,11)12-16, (29,30)31,32,37,38(3 9,40,41,42).

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; in one individual very inconspicuous, vestigial seminal vesicles present in segments 9 and 10. Ovaries and female funnels in segment 13, ovarian receptacles (ovisacs) in segment 14. Two or three pairs of small globular spermathecae in segments (11), 12 and 13 (intersegments 11/12, 12/13, 13/14). Nephridial bladders U-shaped, reclinate in segment 30.

REMARKS

This species displays some degree of morphological variability, with different combinations of extension of clitellum and tubercula pubertatis, position of genital papillae and spermathecae. These different morphotypes do not show any clear association with genetic lineages, and therefore they do not appear to correspond to differentiated taxa within the species described here.

This species corresponds to Sc. corsicana L 6 in the checklist of Corsican earthworms of Marchán et al. (2022a).

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).