Buthus Leach 1815
Creators: name: Kovařík, František
name: Šťáhlavský, František
name: Elmi, Hassan Sh Abdirahman
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Scorpiones
Buthidae
Buthus

description: Buthus Leach, 1815
(Figures 1–211, Tables 1–3)
Buthus Leach, 1815: 391; Fet & Lowe, 2000: 91–97 (complete references list until 1998); Sousa et al., 2017: 15–84, figs. 1–16.
TYPE SPECIES. Scorpio occitanus Amoreux, 1789
DIAGNOSIS. Total length 25–90 mm. Carapace with distinct carinae joined to form a lyre-shaped configuration, in lateral view with entire dorsal surface horizontal or nearly so. Five pairs of lateral eyes and eyespot present. Pectines with fulcra. Pectine teeth number ca 20–40. Mesosoma tergites I–VI with three carina which do not project beyond posterior margin as distinct spiniform processes. Telson without subaculear tubercle. Chelicera with typical buthid dentition, fixed finger with two ventral denticles. Orthobothriotaxic type B, dorsal trichobothria of pedipalp femur arranged in beta -configuration. Patellar trichobothrium d 2 located externally to dorsomedian carina. Trichobothrium eb located on fixed finger of chela. Dentate margin of pedipalp chela movable finger with distinct granules divided into 9–14 rows, 3 terminal granules and one basal terminal granule. Tibial spurs present on third and fourth pairs of legs.
REMARKS ON KARYOTYPES (Figs. 195–209). We analyzed male karyotypes of four Buthus species from the Horn of Africa (Table 3). The cytogenetic characteristics of all species correspond to the typical features of the family Buthidae such as holocentric organization, achiasmatic meiosis in males, and lower number of chromosomes (e. g. Mattos et al., 2013). All examined specimens of Buthus awashensis, B. pococki sp. n. and B. zeylensis possess 2n=22 (Figs. 195, 201, 204, 205, 208). We found only 21 chromosomes in karyotype of analysed Buthus berberensis (Fig. 198). The reduction of the diploid number is probably consequence of heterozygous fusion of chromosomes. This type of chromosomal rearrangement forms conspicuous trivalent during postpachytene (Fig. 199). Moreover, fusion of two chromosomes form one extra large chromosome in the karyotype of this species (Fig. 200). Except Buthus awashensis, the karyotypes of the all analysed species are typical with one pair of chromosomes with distinctive length whereas the subsequent chromosomes are shorter and gradually decrease in length (Figs. 200, 203, 206, 209). Similar one longer pair of chromosomes is known also in karyotypes of all karyotyped Androctonus species (SadÍlek et al., 2015). This similarity of karyotypes may reflect phylogenetic relationships that was already proposed in previous phylogenetic analysis (Fet et al., 2003). We observed multivalent association (ten chromosomes of different length) in Buthus awashensis during postpachytene (Figs. 196–197). This chain of chromosomes is consequence of multiple reciprocal translocations. Although this type of chromosome rearrangement does not affect chromosome numbers, it may however considerably change the size of the chromosomes (e. g. KovařÍk et al., 2015). It is probably the reason why this species has not one extra large pair of chromosomes, the typical feature of the remaining species with only bivalents (Figs. 202, 205, 208). Despite of the mentioned small differences among analysed species, the karyotypes of species from the Horn of Africa fully correspond to those of Buthus occitanus from France (Guénin, 1961), and the karyotypes seem to be very conservative within the genus Buthus.
description: Published as part of Kovařík, František, Šťáhlavský, František & Elmi, Hassan Sh Abdirahman, 2020, Scorpions of the Horn of Africa (Arachnida Scorpiones) Part XXIII Buthus (Buthidae), with description of two new species, pp. 1-32 in Euscorpius 307 on pages 1-3, DOI: 10.5281/zenodo.4648379