Vignysa callasensis Gérard, Decaëns & Marchán, 2023

Gérard, Sylvain, Marchán, Daniel Fernández, Navarro, Alejandro Martinez, Hedde, Mickaël & Decaëns, Thibaud, 2023, Resampling Bouché’s historical localities reveals three new species and helps identifying a new genus of earthworms (Oligochaeta, Hormogastridae and Lumbricidae) in Southeastern France, Zoosystema 45 (23), pp. 749-768 : 759-761

Vignysa callasensis Gérard, Decaëns & Marchán , n. sp.

( Figs 9 ; 10 ; 11 )

urn:lsid:zoobank.org:act:CF80AC3C-631B-4AE4-A58D-83632F1541B1

TYPE MATERIAL. — Holotype. France • 1 adult specimen; Provence-Alpes-Côte d’Azur, Var, 83830 Callas , in the soil; 43°35’13”N, 6°32’16”E; 340 m a.s.l.; 28.XI.2021; T. Decaëns, D. F. Marchán, S. Gérard, R. Della Vedova leg.; MNHN ( BOLD Sample ID: DFM-1062 ).

Paratypes. France • 4 adult specimens; same data as holotype; Eco & Sols ( BOLD Sample ID: DFM-1061, DFM-1065, SG-0057, SG-0058 ) • 4 specimens; same data as holotype; MNHN (BOLD Sample ID: DFM-1064, DFM-1063; SG-0059, SG-0060).

OTHER MATERIAL. — France • 10 adult and 11 sub-adult specimens; same data as holotype; Eco & Sols.

ETYMOLOGY. — The name of the species is derived from the city of Callas in the Var department (Provence-Alpes-Côte d’Azur, France) where the type specimens were found.

ECOLOGY. — Vignysa callasensis Gérard, Decaëns & Marchán , n. sp. was found in a riparian grassland near La Risse stream, at a low elevation (340 m a.s.l.).

DISTRIBUTION. — Vignysa callasensis Gérard, Decaëns & Marchán , n. sp. was found near the city of Callas, in the sedimentary basin North to Esterel, in the Var department (Provence-Alpes-Côte d’Azur, France).

DESCRIPTION

External morphology ( Fig. 9A, B )

Body shape cylindrical. Body pigmentation absent. Gut content visible by transparency. Average body length after ethanol fixation: 95 mm (range: 82 to 150 mm; n = 9 adult specimens; holotype: 100 mm). Average body mass: 0.984 g (range: 0.850 to 1.260 g; n = 11; holotype: 1.260 g). Average diameter: 4.0 mm in the preclitellar region (range: 3.5 to 4.8 mm; n = 11; holotype: 4.8 mm), 4.5 mm in the clitellum (range: 4.0 to 5.4 mm; n = 11; holotype: 5.3 mm), 4.9 mm in the postclitellar region (range: 4.0 to 5.5 mm; n = 11: holotype: 5.5 mm). Average number of segments: 162 (157 to 167; n = 7; holotype: 157). Prostomium of prolobous type. Setae closely paired. Setal arrangement aa:ab:bc:cd:dd = 18:2:8:1:25. Clitellum in XV-XXIII, beginning unclear. Genital markings in XII-XIV and XX-XXIII, in ab. Tubercula pubertatis: thin band in XVII-XXIII, more marked in XX-XXIII. Male pores: one pair in XV. Ovipores not visible. Spermathecal pores not visible. Nephridial pores not visible.

Internal anatomy ( Fig. 9C, D )

Septa: thickened from 7/8 to 9/10, otherwise membranous. Crop: missing. Gizzard: two globular gizzards in VI-VII, of 1.5 mm in diameter. Calciferous glands: absent. OEsophagus-intestine transition in XIII. Typhlosole start in XX or XXII, formed by a Y-shaped large lamellae.Hearts: in VI-XI. Excretory apparatus: one pair of holonephridia per segment, nephridial vesicles boat-hook shaped (bent cecum) in preclitellar segments, open V shaped in the rest of the body. Seminal vesicles: two pairs in XI-XII, large and lobulated. Spermathecae: two pairs in IX-X (9/10, 10/11), intracoelomic, tubular and folded, simple.

REMARKS

This species is the smallest species of the genus Vignysa : 0.850 -1.260 g and 157-167 segments vs 1.400 -2.700 g and 205-232 segments for Vignysa teres ( Bouché 1972; personal data), and 3.500 -4.800 g and 372-396 segments for Vignysa vedovinii ( Rota 1994) (see Table 5 ). It is also the easternmost species within the genus. Alive, it has a viscous texture ( Fig. 11 ) and tends to break easily. It shares with V. vedovinii the absence of blood vesicles.

Figures

FIG. 9. — Vignysa callasensis Gérard, Decaëns & Marchán, n. sp.: A, external view of the anterior body; B, lateral view of the anterior body; C, dissection of the anterior body; D, detail of the anterior body dissection showing the spermathecae. Abbreviations: CL, clitellum; GM, genital marks; GZ, gizzard; IN, intestine; MP, male pore; SEP, septa; SV, seminal vesicles; TP, tubercula pubertatis; TY, typhlosole. Scale bars: A-C, 5 mm, D, 1.5 mm. Photos: T. Decaëns.

FIG. 10. — Pre-clitellar nephridia of Vignysa callasensis Gérard, Decaëns & Marchán, n. sp. Scale bar: 1 mm. Photo: D. F. Marchán.

FIG. 11. — Living specimen of Vignysa callasensis Gérard, Decaëns & Marchán, n. sp. Photo: S. Gérard.