Chaerilus neradorum, Kovařík & Lowe & Šťáhlavský, 2018

Kovařík, František, Lowe, Graeme & Šťáhlavský, František, 2018, Three new Chaerilus from Malaysia (Tioman Island) and Thailand (Scorpiones Chaerilidae) with a review of C cimrmani C sejnai and C tichyi, Euscorpius 268, pp. 1-27 : 7-16

Chaerilus neradorum sp. n.

( Figs. 44–67, 117–118, Table 1) http://zoobank.org/urn:lsid:zoobank.org:act:21E879

2C-9989-4747-A6BD-FD75CD80F989

T YPE LOCALITY AND TYPE REPOSITORY. Thailand, Samui , 9.46555°N 99.98419°E ; FKCP.

TYPE MATERIAL. Thailand, Samui , 9.46555°N 99. 98419°E ( Fig. 44), 1♂ (1216), leg. L. Nerad , FKCP.

ETYMOLOGY. The specific epithet honors Ladislav Nerad and his wife Hana ( Czech Republic) for their invaluable contributions to the knowledge of the scorpion fauna of Thailand.

DIAGNOSIS. Total length of male holotype 23.25 mm. Two pairs of lateral eyes and one pair of median eyes.

Chela length/width ratio in male 2.4. Movable and fixed fingers of pedipalp with 11 imbricated granule rows. Fingers straight. Chela of pedipalp with 8 carinae. Pectinal teeth number 6 in males. Carapace and tergites sparsely granulated. All sternites smooth without carinae and granules. First metasomal segment with 10

carinae, second to fourth segments with 8 carinae. All metasomal segments very sparsely granulated.

DESCRIPTION. Total length of male holotype 23.25 mm, female unknown. Two well developed pairs of lateral eyes and one pair of median eyes. The chelicerae are finely granulated, yellow and strongly reticulate, anteriorly black. For the position and distribution of trichobothria, see Figs. 52–58. For measurements, see Table 1.

COLORATION ( Figs. 45–46). The color is orange to brown, spotted.

CARAPACE AND MESOSOMA ( Figs. 47–48). The entire carapace is covered by large granules which do not form carinae. The anterior margin of the carapace is almost straight to weakly concave. The mesosomal tergites are irregularly, sparsely granulated. All sternites are smooth without carinae and granulation. Sternite V with smooth patch weakly indicated. Pectinal teeth number 6 in male holotype.

METASOMA AND TELSON ( Figs. 49–51). The first metasomal segment bears 10 carinae, the second to fourth bear eight carinae, and the fifth segment bears seven carinae of which one ventral carina posteriorly branches in a "Y" configuration. All carinae are composed of large, sparse granules. The spaces between carinae are irregularly very sparsely granulated on all surfaces, less so on the dorsal surface. Granules on the dorsal surface may indicated a pair of carinae. All segments are sparsely hirsute. The telson is elongate, smooth and sparsely hirsute.

PEDIPALPS ( Figs. 52–61). The pedipalp chela is wide and swollen in the male. The movable and fixed fingers of pedipalp bear 11 imbricated rows of granules. The chela has eight partly granulated carinae. The patella has five only weakly indicated carinae and the femur has four or five partly granulated carinae. The spaces between carinae on the femur are covered by unevenly spaced granules. The chela is finely granulated and the patella is smooth except for several solitary granules on their internal surfaces.

LEGS ( Figs. 62–66). The legs are sparsely hirsute, without bristlecombs and carinae. The femora and patellae have several granules dorsally, other surfaces are smooth. The patellae have several median spines dorsally. The tarsomeres bear two rows of spiniform setae and 2 – 4 outer spiniform setae. Spiniform setae formula is 5–6/6–7: 6–7/7–8: 7–8/8–9: 7–8/7–9 (omitting outer spiniform setae).

KARYOTYPE ( Figs. 117–118). We analyzed the karyotype of the male holotype. The diploid complement of this species is 108 chromosomes in the majority of mitotic metaphases ( Fig. 117). However, the chromosomes are small and the correct number is not easy to count in some observed cells as a consequence of an early segregation of some chromatids during mitotic metaphase. This effect is evident especially in segregation of chromosomes during late metaphase I ( Fig. 118). It is the reason we cannot exclude even 106 as the correct diploid number of chromosomes in this species. We are not able to specify morphology of the chromosomes at this moment. However, it is evident that they gradually decrease in length from 2.63% to 1.07% of the haploid set. We did not observe chiasmata during postpachytene and metaphase I.

AFFINITIES. Chaerilus neradorum sp. n. is reliably distinguished from all other Chaerilus species by the following unique combination characters: total length of male holotype 23.25 mm; movable and fixed fingers of pedipalp with 11 cutting edges; chela length/width ratio in male 2.4; fingers straight in male.

Type locality of C. neradorum sp. n. is inside the area of distribution of C. cimrmani Kovařík, 2012 which can be distinguished from C. neradorum sp. n. by larger size (total length of male holotype 23.25 mm for C. neradorum sp. n. vs. 31–42 mm of C. cimrmani ). Other differences are evident in comparing Figs. 52 versus 105, which shows that the male of C. cimrmani has wider, more swollen chelae, shorter chela fingers, and stronger granulation of carapace and metasomal segments, than the male of C. neradorum sp. n.