New Species of the Digger Scorpions, Odontobuthus Vachon, 1950 (Buthidae) from Southern Iran

© 2024 Academia Sinica, Taiwan Open Access New Species of the Digger Scorpions, Odontobuthus Vachon, 1950 (Buthidae) from Southern Iran Hossein Barahoei1,* and Mehran Shahi2 1Department of Agronomy and Plant Breeding, Agriculture Research Institute, Research Institute of Zabol, Zabol, Iran. *Correspondence: E-mail: [email protected] (Barahoei) 2Department of Medical Entomology & Vector Control, School of Public Health, Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran. E-mail: [email protected] (Shahi) urn:lsid:zoobank.org:pub:91DB3026-562A-4DDF-9668-72DCB3DF927F Received 21 May 2024 / Accepted 9 September 2024 / Published 25 December 2024 Communicated by Jen-Pan Huang Odontobuthus Vachon, 1950, with nine described species, is a genus of digger scorpions in the Buthidae family, which can be distinguished by having large tooth-like processes on the ventrosubmedian carinae of the second and third metasomal segments. Morphological and molecular investigation of coastal specimens from the Hormozgan province in Iran led to the discovery of a new species named Odontobuthus persicus sp. nov. that is described here. It is closely related to O. chabaharensis morphologically. The new Odontobuthus species has two large and conical tooth-like processes on ventrosubmedian carinae of the second and third metasomal segments, while O. chabaharensis has three or four medium to large tooth-like processes. Based on phylogenetic analysis using partial COI sequences, the new species is placed as a sister taxon of O. brevidigitus. Genetic differences with the other species of Odontobuthus (mean = 0.107) confirmed the validity of this species. Key words: Odontobuthus, COI, Genetic distance, Hormozgan, Taxonomy Citation: Barahoei H, Shahi M. 2024. New species of the digger scorpions, Odontobuthus Vachon, 1950 (Buthidae) from Southern Iran. Zool Stud 63:48. doi:10.6620/ZS.2024.63-48. BACKGROUND Odontobuthus Vachon, 1950 is a genus of scorpions in the Buthidae family. Members of this genus are diggers that rest in burrows during the day, leaving at night to hunt, but they do not go far from it. They are medium to large-sized scorpions with large tooth-like processes on ventrosubmedian carinae of the second and third metasomal segments (Lourenço and Pézier 2002; Lowe 2010; Barahoei et al. 2022). They are easily recognizable by this character and named based on this character (Vachon 1950; Dupré 2016). Odontobuthus, with two species, was separated from Buthus by Vachon (1950). Now, this genus consists of nine species, of which six species are distributed in Iran (Odontobuthus baluchicus Barahoei et al., 2022, Odontobuthus chabaharensis Barahoei et al., 2022, Odontobuthus doriae Thorell, 1876, Odontobuthus kermanus Barahoei et al., 2022, Odontobuthus tavighiae Navidpour et al., 2013, Odontobuthus tirgari Mirshamsi et al., 2013), one species in Iraq and Iran (Odontobuthus bidentatus Lourenço & Pézier, 2002), one species in Pakistan and India (Odontobuthus odonturus Pocock, 1897), and one species in Oman and the United Arab Emirates (Odontobuthus brevidigitus Lowe, 2010) (Barahoei et al. 2020 2022). According to the literature, seven species have been described for this genus in the last two decades (Lourenço and Pézier 2002; Lowe 2010; Mirshamsi et al. 2013; Navidpour et al. 2013; Barahoei et al. 2022). The validity of all species was confirmed by Barahoei et al (2022). The Zagros mountains’ uplift led to lacertid lizards speciation (Macey et al. 1998). eological events in the south of Iran caused separation and speciation Zoological Studies 63:48 (2024) doi:10.6620/ZS.2024.63-48 1 © 2024 Academia Sinica, Taiwan in terrestrial fauna; the same was happened for as the population of Odontobuthus species (Lowe 2010). For this reason, the greatest species diversity of Odontobuthus is in the south of Iran, where O. tavighiae and O. baluchicus have been described from the west and east of the Hormozgan province, respectively (Navidpour et al. 2013; Barahoei et al. 2022). The purpose of this research was morphological and molecular investigation of specimens collected from the southern coast of Iran in Hormozgan province. MATERIALS AND METHODS Sampling locality Hormozgan province, in the southern part of Iran, is located between 25°23'–28°57'N and 52°41'–59°15'E (http://www.hormozgan.doe.ir). Specimens were collected by digging in the day in the east of Bandar Abbas county, south of Iran (Fig. 1). Some samples were loaned from the Children’s Hospital, Bandar Abbas, Hormozgan province, Iran (delivered by people who were stung by these scorpions). Specimens were placed in 80% ethanol and deposited in the collection of the Research Institute of Zabol, Zabol, Iran (RIZ) and Zoological Museum, Ferdowsi University of Mashhad, Mashhad, Iran (ZMFUM). Morphometric measurements done based on Stahnke (1970) and Sissom (1990) using a graduated lens mounted on an Optika stereo-microscope (Italy). Photography done using a Canon® EOS 800D digital camera (Japan). Photographes were edited with Adobe Lightroom version 6.0 and Adobe Photoshop CS5. A distribution map for type specimens of Odontobuthus species was constructed in SimpleMappr (https://www. simplemappr.net). Molecular analysis The DNA was extracted from the dissecting muscle tissue of legs using the Favorgen genomic DNA Extraction kit (Taiwan). The partial sequence of the Fig. 1. Recorded occurrence of Odontobuthus persicus sp. nov.: A, B) General habitat, C, D) Nest entrance. page 2 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan mitochondrial cytochrome c oxidase, subunit I (COI) gene, was amplified using LCO1490 and HCO2198 (Folmer et al. 1994) under a three-step thermocycling protocol (Barahoei et al. 2022). Each PCR reaction contained 12 μl of master mix (Ampliqon, Denmark), 8 μl deionized H2O, 1 μl of each primer, and 3 μl of DNA template. Sequencing was carried out using a FlexCycler (Analytikjena, Germany). Purification and sequencing of amplified genes were done by Niagene Noor Company (Tehran). Five new COI sequences were deposited in GenBank [ncbi. nlm.nih.gov] with the accession numbers PQ212541 to PQ212545. Sequences were edited and aligned using Bioedit version 7.1.9 (Hall 1999). Genetic distances within and between species were investigated with MEGA 7.0 (Kumar et al. 2016). Bayesian inference (50.000.000 generations, burn-in = 5000) using MrBayes 3.2.7a (on the website http://www.phylo.org) and Maximum likelihood (10,000 iterations, with GTR+G substitution model) using PhyML 3.0 software (on the website http://www.atgc-montpellier.fr/phyml) (Guindon et al. 2010) were done. FigTree v1.4.0 was used in order to edit and view the generated trees (tree.bio.ed.ac.uk/ software/figtree). Buthus occitanus (Amoreux 1789) and B. paris (C. L. Koch 1837) (the most primitive species), considered closely related to Odontobuthus, were used as outgroups. RESULTS Phylogenetic analysis A phylogenetic tree was constructed based on 38 sequences of the genus Odontobuthus (33 from NCBI and five new) and two sequences of the genus Buthus as outgroups (Table 1). Sequence length was 627 bp, including 453 conserved (72.25%), 174 variable (27.75%), and 146 parsimonious (23.28%) nucleotides. The trees generated using Maximum likelihood (ML) and Bayesian interference (BI) revealed that O. kermanus and O. tirgari were placed sister to all other Odontobuthus species, and the Odontobuthus persicus sp. nov. was found as youngest species and sister to O. brevidigitus (Fig. 2). Genetic differences between this species and other Odontobuthus species (average distance = 0.107) (Table 2) supported the validity of this species. The intraspecific distance for this species is 0.012 (Table 2). Among Odontobuthus members, the lowest genetic difference was between O. kermanus and O. tirgari (0.054), and the highest was between O. persicus sp. nov. and O. doriae (0.129) (Table 2). TAXONOMY Order Scorpiones C. L. Koch, 1837 Family Buthidae C. L. Koch, 1837 Genus Odontobuthus Vachon, 1950 Odontobuthus persicus sp. nov. (Figs. 3, 4, Table 3) urn:lsid:zoobank.org:act:87D23AB8-BED8-4DF3-BE45AE15B15F4E69 Type material: Holotype: ♀ (Figs. 3, 4), IRAN, Hormozgan Province, Bandar Abbas County, Baghu village, 27°19'N, 56°27'E, 15 m a.s.l (Fig. 1), daytime excavation, 09 March 2013, leg. M. Shahi (RIZOdo-015). Paratypes: Hormozgan Province: 1♀ (RIZOdo-012), Bandar Abbas County, Baghu village, 27°19’N, 56°27’E, 15 m a.s.l, 2014, leg. H. Ahmadi; 1♂ (RIZ-Odo-004), 26 August 2015, leg. A. Jafari; 1♂ (RIZ-Odo-065) (Figs. 5, 6), 06 January 2023, leg. M. Moradi and M. Shahi; 1♀ subadult (RIZ-Odo-113), 04 March 2023, leg. M. Shahi - 1♂ (RIZ-Odo-063), Jallabi village, 27°20’N, 56°31’E, 22 m a.s.l, 14 June 2022, leg. M. Shahi; 1♂ (RIZ-Odo-059) (Fig. 7), 13 August 2022, leg. M. Shahi; 1♂ (RIZ-Odo-058), 14 September 2022, leg. M. Ghoreyshi; 2♀, 1♂ (RIZ-Odo-057), 27 October 2022, H. Barahoei and M. Shahi. Etymology: The species name is derived from the term ‘Persia’ that has been used for centuries and originated from a region of southern Iran formerly known as Persis. Diagnosis: Scorpions of small to medium size, adults ranging from 48.7–57 mm in females and 55.1–62.5 mm in males; general colouration light yellow; dentate margins of fixed and movable fingers of pedipalps with 10–12 rows of oblique denticles; pectinal teeth 31–33 in males and 21–23 in females; ventrosubmedian carinae of metasomal segments II–III with two pairs of large tooth-like processes; metasomal segment IV L/W 1.62–2.05; ventrolateral carinae of metasomal segment V with two strong lobate denticles; lateral anal arch armed with three strong lobes; posterior ventral margin of metasomal segment V with two large lobes; small and wide telson (L/W 2.38–2.72; L/D 2.48– 2.85), oval vesicle (L/W 1.25–1.59; L/D 1.33–1.66; W/ D 1.03–1.07) (Table 3). Description: Female holotype (ZMFUM-Odo-015) (Figs. 3, 4) Colour: Light brown to yellow, median and lateral eyes and end of telson dark, other parts yellow (Fig. 3). Chelicerae: Two basal denticles on the ventral surface of the fixed finger, with equally sized external and internal distal denticles. page 3 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan Table 1. Data from scorpion specimens that were used for sequencing the COI gene and NCBI sequences of Odontobuthus spp. and two species of Buthus as outgroups Species Collection Locality GenBank O. bidentatus Lourenço & Pézier, 2002 ZMFUM IRAN, Fars Province KF701317 IRAN, Khuzestan Province KF701314 MW655776 IRAN, Bushehr Province MW655752 O. baluchicus Barahoei et al., 2022 ZMFUM IRAN, Sistan and Baluchistan Province MW655753 MW655754 MW655755 IRAN, Hormozgan Province MW655756 O. brevidigitus Lowe, 2010 AMCC, ZMFUM OMAN MW655773 MW655777 MW655778 O. chabaharensis Barahoei et al., 2022 ZMFUM IRAN, Sistan and Baluchistan Province MW655757 MW655758 O. doriae Thorell, 1876 AMCC, ZMFUM IRAN, Yazd Province MW655779 IRAN, Tehran Province MW655780 IRAN, Semnan Province MW655795 O. kermanus Barahoei et al., 2022 AMCC, ZMFUM IRAN, Kerman Province KF701326 MW655759 MW655760 MW655775 O. odonturus Pocock, 1897 AMCC PAKISTAN MW655781 MW655782 MW655783 MW655784 O. persicus sp. nov. RIZ-Odo-57A RIZ-Odo-57B RIZ-Odo-57C RIZ-Odo-058 IRAN, Hormozgan Province, Jallabi village PQ212541 PQ212542 PQ212543 PQ212544 RIZ-Odo-063 IRAN, Hormozgan Province, Baghu village PQ212545 O. tavighiae Navidpour et al., 2013 ZMFUM IRAN, Hormozgan Province MW655761 MW655762 IRAN, Fars Province MW655763 MW655764 O. tirgari Mirshamsi et al., 2013 ZMFUM IRAN, Razavi Khorasan Province KF701319 KF701322 IRAN, Sistan and Baluchistan Province MW655765 MW655768 IRAN, South Khorasan Province MW655766 B. paris (C.L. Koch, 1837) - MOROCCO KF548111 B. occitanus (Amoreux, 1789) - SPAIN GQ168524 AMCC: Ambrose Monell Cryocollection at the American Museum of Natural History. page 4 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan Fig. 2. Bayesian inference tree obtained by sequences of mitochondrial COI gene from Odontobuthus. Two sequences of the genus Buthus were used as outgroups. The numbers above branches represent posterior probability and bootstrap values from Bayesian inference and maximum likelihood analyses, respectively. Table 2. Average Kimura 2-parameter (K2P) genetic distance among and within (bold) species of Odontobuthus and two species of Buthus based on COI gene sequences 1234567891011 1. O. bidentatus 0.023 2. O. baluchicus 0.092 0.029 3. O. brevidigitus 0.100 0.103 0.040 4. O. chabaharensis 0.092 0.095 0.083 0.017 5. O. doriae 0.123 0.118 0.128 0.114 0.012 6. O. kermanus 0.102 0.099 0.109 0.106 0.126 0.021 7. O. odonturus 0.100 0.084 0.109 0.100 0.118 0.107 0.009 8. O. persicus sp. nov. 0.113 0.110 0.082 0.088 0.129 0.119 0.127 0.012 9. O. tavighiae 0.086 0.098 0.077 0.079 0.112 0.093 0.115 0.086 0.006 10. O. tirgari 0.098 0.090 0.110 0.104 0.118 0.054 0.107 0.110 0.093 0.0 11. B. paris 0.129 0.122 0.129 0.115 0.137 0.124 0.126 0.125 0.128 0.117 - 12. B. occitanus 0.107 0.144 0.132 0.127 0.134 0.114 0.123 0.135 0.119 0.126 0.129 page 5 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan Pedipalps: Femur: three times longer than wide with four complete granular carinae; intercarinal surfaces smooth. Patella: 2.71 times longer than wide. Chela: three times longer than manus; manus wider than patella; fingers not very long, 1.9 times longer than manus; number of primary denticle subrows: fixed finger 10 right, 10 left; movable finger 10 right, 10 left; all oblique rows of denticles except proximal flanked by external and internal accessory granules; movable finger with five subdistal granules, one internal and four external; trichobothrium et adjacent to the mid part of denticle subrow 6; est adjacent to proximal end of denticle subrow 8. Carapace: Trapezoid shaped; ocular tubercle located on anterior half of prosoma, five pairs of lateral ocelli; wider than long (CWA/CL:0.71; CWP/CL: 1.15); carination developed, central lateral and posterior median carinae completely aligned; anteromedian and posteromedian sulcus shallow; posterolateral furrow wide and curved (Fig. 4A). Mesosoma: Tergites I–VI tricarinate; tergite VII pentacarinate, median carinae on tergite VII granulate, incomplete in posterior one-third (Fig. 4A); sternites III–VI without carinae; sternite VII with four moderately developed carinae (Figs. 3B, 4B); pectines not extending beyond the coxa-trochanter joint of the leg IV; with three marginal and seven median lamellae; fulcra present; pectinal tooth count 23|23; sternum type I sub-pentagonal and longer than wide with a deep median depression; genital operculum completely divided longitudinally (Figs. 3B, 4B). Legs: Ventral surface of tarsi with two rows of fine setae, legs III–IV with tibial spurs, legs III–IV with 17–18 and 4–5 long setae on the tarsus, respectively (Fig. 3). Metasoma: Segment I with 10 carinae; segment II–IV with eight carinae; median lateral carinae of segment II nearly complete; lateral inframedian carinae of segment III incomplete and present only on posterior half with four separate granules; ventral carinae on segments II–III strongly dentate with two distinct posterior conical denticles (Fig. 4C–E); anterior ventral margin of segments III–IV with six large and conical denticles; segment V with five carinae; ventrolateral carinae on segment V dentate without large posterior denticles; ventral posterior margin of metasomal segment V with two large conical denticles; lateral anal arch with three large separate conical lobes (Fig. 4D–E). Fig. 3. Female specimen of Odontobuthus persicus sp. nov. A) dorsal view, B) ventral view (RIZ-Odo-015). page 6 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan Fig. 4. Female specimen of Odontobuthus persicus sp. nov. A, carapace and tergites; B, sternites; C, lateral view of metasomal segments II and III; D, lateral view of metasomal segments and telson, E) ventral view of metasomal segments and telson (RIZ-Odo-015). page 7 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan Table 3. Morphometric data of Odontobuthus persicus sp. nov. Dimensions (mm) Odontobuthus persicus sp. nov. 12 ♀15 ♀57 ♀04 ♂59 ♂65 ♂ Pedipalp Femur L W 5.8 2 4.8 1.6 5.2 1.7 5.7 1.7 6.2 1.7 6.7 1.9 Patella L W 6.7 2.2 5.7 2.1 6.3 2.1 6.6 2.3 7.1 2.3 7.5 2.4 Manus L W D 4.3 2.5 2.8 3.7 2.2 2.4 3.9 2 2.2 3.9 2.3 2.5 4.5 2.5 2.7 5 3.2 3.6 Movable finger L 8 7.2 7.6 7.6 8.1 9 Carapace L WA WP 7.1 5.2 8.8 5.9 4.2 6.8 6 4.3 7 6.6 4.6 7.6 7 5.7 7.8 7.6 5.2 8.6 Mesosoma Total L 14.2 13 12.7 12.6 14.2 15 Tergite 4 W 10.6 8.5 8.5 8.5 9.6 10.3 Metasomal Segments I L W D 4.5 4.4 3.6 3.8 3.3 2.7 3.5 3.5 3 4 4.5 3.6 4.7 4.6 3.8 5 4.5 3.7 II L W D 5 4.2 3.5 4.3 3 2.6 4.2 3.2 2.8 5.1 4.1 3.7 5.2 4.1 3.7 5.7 4 3.5 III L W D 5.3 4 3.5 4.4 2.8 2.6 4.5 3.1 2.8 5.5 3.9 3.8 5.5 3.8 3.7 6 3.6 3.5 IV L W D 6 3.7 3.1 5 2.8 2.4 5.3 3 2.6 6.7 3.5 3.3 6.6 3.5 3.4 7.2 3.5 3.2 V L W D 7.5 3.5 2.7 6.5 3.1 2.1 6.5 2.6 2.2 7.8 3 2.9 7.7 3.1 3 8.1 3.1 2.8 Telson Vesicle L W D 4.4 3.4 3.3 3.6 2.6 2.5 3.5 2.2 2.1 4.1 2.9 2.8 4.2 3 2.8 4.7 3.2 3.1 Aculus L 3 2.6 2.5 2.7 2.8 3.2 Pectinal teeth Left Right No. No. 23 23 23 23 21 21 32 33 32 32 31 32 Chela Denticle Row Number Movable finger Left Right 10 10 10 10 10 10 10 10 11 11 12 12 Fixed finger Left Right 10 10 10 10 10 10 10 10 10 10 11 - Total length 57 49.1 48.7 55.1 57.9 62.5 D: depth, L: length, W: width, WA: wide in anterior part, WP: wide in posterior part. page 8 of 13Zoological Studies 63:48 (2024) © 2024 Academia Sinica, Taiwan Telson: Oblong-ovoid, with dorsal surface flat (TD/TL: 0.40; TW/TL: 0.41); ventral surface of telson smooth; not wider than metasomal segment V (TW/ Mt(V)W: 0.84) (Fig. 4D–E). Measurements (holotype: ZMFUM-Odo-015): Given in the table 3. Male (paratype: RIZ-Odo-065) (Figs. 5, 6) Same as female [holotype] with differences below: Femur: 3.5 times longer than wide; patella: 3.1 times longer than wide; manus wider than patella; fixed finger, 11 left; movable finger 12 right, 12 left; trichobothrium et adjacent to denticle subrow 7; est adjacent to denticle subrow 9; Carapace wider than long (CWA/CL: 0.68; CWP/CL: 1.13) (Fig. 6A); pectinal tooth count 31|32 (Figs. 5B, 6B, Table 3); Telson narrower than female (TD/TL: 0.39; TW/TL: 0.40); wider than metasomal segment V (dorsal part wide) (TW/Mt(V)W: 1.03) (Fig. 6C, Table 3). Measurements: Given in the table 3. Distribution: Hormozgan province, south of Iran. Affinities: Odontobuthus persicus sp. nov. is separated from O. baluchicus, O. doriae, O. kermanus, and O. tirgari by having three long triangular lobes (Figs. 4D, 6C) in the lateral part of the anal arch (against two lobes, figs. 7A, 13A, 20A, 20C, 20F in Barahoei et al. 2022). This species can be distinguished from O. bidentatus and O. tavighiae by having two large lobes in the ventral part of the 5th metasomal segment (Fig. 4E) against four to six short lobes (figs. 21A, 21E in Barahoei et al. 2022). In addition, this species has 10– 12 rows of oblique teeth on the movable finger of the manus, while the above two species have 13–14 rows of oblique teeth. Odontobuthus persicus sp. nov. is smaller than all the species mentioned above and lives in low altitudinal, coastal areas, whereas all other species mentioned above are found in mountainous areas. This species can be distinguished from O. brevidigitus by having a narrow manus and a relatively long movable finger (Fig. 3) against a short and wide movable finger in O. brevidigitus (fig. 16A–D in Barahoei et al. 2022). O. brevidigitus is also distributed in Oman and UAE, but there are no records from Iran (Lowe 2010). The anal arch of metasomal segment V of O. odonturus has six reduced lobes (figs. 16E and 21D in Barahoei et al. 2022) and is distributed in India and Pakistan, while the anal arch has two distinct lobes in O. persicus sp. nov. (Fig. 4E), which is only distributed in Fig. 5. Male specimen of Odontobuthus persicus sp. nov. A) dorsal view, B) ventral view (RIZ-Odo-065). page 9 of 13Zoological Studies 63:48 (2024)