Buthacus sadinei, Ythier, 2022

Ythier, Eric, 2022, A new species of Buthacus Birula, 1908 from Western Algeria (Scorpiones: Buthidae), Faunitaxys 10 (28), pp. 1-6 : 2-4

Buthacus sadinei sp. n.

( Fig. 1 -9 )

ZooBank: http://zoobank.org/ 87AE7069-56FC-49F5-9E4F-3AFB379D2BDC

Holotype, ♂, Algeria, Sahara , Tindouf, IV/1971 (D. Louis), D. Bruno & D. Jean-Marc leg., 2005 (No. 2005.60), deposited in the MHNL (47023175).

Etymology. – Patronym in honour of Dr. Salah Eddine Sadine, Ghardaïa, Algeria, for his contributions to the study of scorpions from Algeria.

Diagnosis. –Scorpions of moderate size with a total length of 56.2 mm for the male holotype. General coloration yellowish without any spots. Male pectines long with the marginal tips extending to the end of sternite V;pectinal tooth count 29-30.Metasomal segmentI with 10 complete carinae, II-IV with 8 complete carinae; segment V with 36 long setae. Telson with aculeus very long and curved. Chela fingers almost straight, with 9 rows of granules on fixed finger, 10 on movable finger; external accessory granules moderate to strong. Tibial spurs moderate on leg III, long on IV.TrichobothriotaxyA-β (beta)orthobothriotaxic.

Description (based on male holotype).

Coloration. – Generally yellowish without any spots or pigmented zones on the body and appendages. Prosoma: carapace yellowish; only the eyes surrounded by black pigment. Mesosoma : yellowish. Metasoma: all segments yellowish. Vesicle yellowish; aculeus yellowish at the base and reddish at its extremity. Venter yellowish; pectines yellowish. Chelicerae yellowish without any reticulation; teeth reddish. Pedipalps: yellowish overall, paler than body; the rows of granules on the dentate margins of the fingers reddish. Legs yellowish, paler than body.

Morphology. – Prosoma: Anterior margin of carapace not emarginate, straight, bearing twelve macrosetae. Carapace carinae weak; anterior median carinae obsolete; central median, posterior median and central lateral carinae weak. All furrows weak to obsolete. Intercarinal spaces moderately to slightly granular. Median ocular tubercle slightly anterior to the centre of the carapace; median eyesseparatedbyabouttwo ocular diameters.Five pairsof lateraleyes; the first three disposed in one line, the fourth and fifth situated behind eye three. Mesosoma :Tergites I-VItricarinate;allcarinae weak; lateral carinae vestigial on segment I; tergite VII pentacarinate, with lateral pairs of carinae strong; median carinae present on proximal one-half, moderately marked. Intercarinal spaces with fine granulation in central area of tergites, with coarse andfine granulation onlateralsides.Sternitessmooth;allcarinaeabsentfrom sternitesIII-VI; sternite VIIwith two pairs of smoothcarinae.Pectineslongwith the marginaltips of the pectines extending to the end of sternite V; pectinal tooth count29-30; pectines with 3 marginal lamellae and 8 middle lamellae; lamellae and fulcra with numerous setae. Metasoma: Segment I with 10 complete carinae, II-IV with 8 complete carinae (lateromedial carinae on segment II indicated by several granuleson posterior part only);ventral carinae weak onsegments I-IV; dorsal and dorsolateral carinae with granules slightly spinoid on segments I and II. SegmentV with5 carinae;ventrolateralarmedwithspinoidgranulesand several strongspinoid lobes. Dorsalfurrows of all segments weakly developed; dorsal and lateralintercarinalspacessmoothonallsegments; ventralintercarinalspaces smooth on segments I-IV, weakly granulated on V. Segment V with 36 long setae. Anal arc composed of 12 ventral teeth and two lateral lobes. Telson smooth.Aculeus very long and curved; subaculear tubercle absent. Chelicerae with two reduced but not fused denticles at the base of the movable finger ( Vachon, 1963). Pedipalps: Trichobothrial pattern orthobothriotaxic, type A ( Vachon, 1974); chela fixed finger withtrichobothria et situated anteriorly to dt; dorsal trichobothria of femur in β (beta) configuration ( Vachon, 1975). Femur pentacarinate; all carinae moderately crenulate. Patella and chela with vestigial carinae only,almost smooth.Chelafingersalmost straight, withdentate margins composedof 9rowsof granulesonfixedfinger, 10onmovable finger;eachrow with one external and one internal accessory granule, both moderate to strong; 4 terminal granules next two the terminal denticle. Legs: Ventral aspect of tarsi with numerous thin long setae.Tibial spurs moderate on leg III, long on IV.

Morphometric values (mm) (male holotype).

– Total length (including telson length): 56.2.

– Carapace

length 6.1;

anterior width 2.95;

posterior width 7.05.

– Mesosoma : length: 11.05.

– Metasomal segments

I, length 5.05; width 3.81;

II, length 6.00; width 3.71;

III, length 6.19; width 3.52;

IV, length 6.76; width 2.95;

V, length 7.62; width 2.86; depth 2.57. – Telson: 7.43.

– Vesicle: length 3.33; width 2.10; depth 2.00.

– Pedipalp

femur, length 5.43; width 1.62; patella, length 6.67; width 2.10; chela, length 9.71; width 2.38; depth 2.67;

– Movable finger: 5.71.

Morphometric ratios.

– Metasomal segment V length/width 2.66; length/depth 2.96.

– Pedipalp chela length/width 4.08; length/depth 3.64; Chela length/movable finger length 1.70.

– Telson length/width 3.54; length/depth 3.72;

– Vesicle length/ Aculeus length 0.81.

Relationships. – Buthacus sadinei sp. n. shows similarities with regard to several morphological characters as well as a similar biotope, with Buthacus algerianus described from Western Algeria.

The new species can however be easily distinguished from B. algerianus notably by:

(i) its larger size (43-44 mm in B. algerianus );

(ii)8 complete carinae on metasomal segment II (10 in B. algerianus );

(iii) chela fingers with 9-10 rows of granules on fixed and movable fingers (10- 10 in B. algerianus ) with external accessory granules moderate to strong (reduced in B. algerianus );

(iv) tibial spurs moderate on leg III, long on IV (moderate on III-IV in B. algerianus ).

Buthacus sadinei sp. n. can also be easily distinguished from other species associated to the Buthacus leptochelys complex occurring in Northern Mauritania, Northern Western Sahara and Morocco, by the different biotope (see relief map in Fig. 10 ) as well as by the following main features:

- B. occidentalis from Mauritania:

The new species has:

(i) a larger size (44-50 mm in B. occidentalis );

(ii) chela fingers with 9-10 rows of granules on fixed and movable fingers (9- 9 in B. occidentalis );

(iii) tibial spurs moderate on leg III, long on IV (extremely reduced or absent on III, moderate on IV in B. occidentalis ).

- B. stockmanni from Western Sahara and Morocco:

The new species has:

(i) a carapace uniformly yellowish (orange to brown area on the anterior part of carapace in B. stockmanni );

(ii) much less inflated chela manus, with almost straight fingers (male chela manus very inflated and fingers strongly twisted in B. stockmanni );

(iii) chela fingers with 9-10 rows of granules on fixed and movable fingers (9- 9 in B. stockmanni ).

- B. ziegleri from Morocco:

The new species has:

(i) lateromedial carinae of metasomal segment II indicated by several granules on posterior part (such granules are present on both II-III in B. ziegleri );

(ii) 36 setae on metasomal segment V (less than 32 in B. ziegleri );

(iii) chela fingers with 9-10 rows of granules on fixed and movable fingers (11- 9 in B. ziegleri ).

- B. mahraouii from Morocco:

The new species has:

(i) a larger size (50 mm in B. mahraouii );

(ii) smaller pectinal tooth count (36-37 in male B. mahraouii );

(iii)8 complete carinae on metasomal segment II (10 in B.mahraouii );

(iv) chela fingers with 9-10 rows of granules on fixed and movable fingers (9-10 in B. mahraouii );

(v) external accessory granules moderate to strong (reduced in B. mahraouii );

(vi) chela fixed finger with trichobothria et situated anteriorly to dt (same level in B. mahraouii );

(vii) tibial spurs moderate on leg III, long on IV (vestigial on III, reduced on IV in B. mahraouii ).

- B. maroccanus from Morocco:

The new species has:

(i) a larger size (40 mm in B. maroccanus );

(ii) chela fingers with 9-10 rows of granules on fixed and movable fingers (9- 9 in B. maroccanus );

(iii) external accessory granules moderate to strong (reduced in B. maroccanus );

(iv) tibial spurs moderate on leg III, long on IV (moderate on III-IV in B. maroccanus ).

Figures

Fig. 1-2. Buthacus sadineisp. n.,♂ holotype, habitus (dried specimen). 1. Dorsal aspect. 2. Ventral aspect.

Fig. 3-9. Buthacus sadinei sp. n., ♂ holotype (Scale bars = 2 mm). 3. Metasomal segment V and telson, lateral aspect. 4. Cutting edge of pedipalp chela movable finger with longitudinal series of granules. 5-9. Trichobotrial pattern. 5. Chela, dorso-external aspect. 6. Chela, ventral aspect. 7. Patella, dorsal aspect. 8. Patella, external aspect. 9. Femur, dorsal aspect.

Fig. 10. Relief map of Western Algeria, Southern Morocco and Northern Western Sahara, showing the known distribution of the Buthacus species occurring in the region, including elevation of indicated localities.