Material examined listed in Tab. 2.

Etymology

The specific epithet is a Latinisation of the English word ‘serendipitous’, the adjective form of the word ‘serendipity’, and should be treated as a noun. The name, ‘serendipitus’, refers to the serendipitous circumstances surrounding the discovery of the species, including the inadvertent introduction of the species from its native origin, which is as of yet undetermined, to a tropical hothouse in Denmark.

Diagnosis

The new species is assigned to the genus Bamazomus, based on the following characters: (1) mesal spur on pedipalpal trochanter, (2) presence of an accessory tooth on the movable cheliceral finger, (3) female genitalia with numerous spermathecal lobes, and (4) male flagellum dorsoventrally flattened.

The female can be distinguished from other Bamazomus ssp. by the combination of the shape of the chitinized arch, 5 pairs of long spermathecal lobes (some lobes might be basally bifurcated), and a long and distally distinctly bifurcated gonopod. The gonopod is very similar to that of Bamazomus siamensis (Hansen, 1905) (illustrated in Cokendolpher & Reddell (1986)) which differs by having very short spermathecal lobes. The male B. serendipitus sp. n. can be distinguished from other species of Bamazomus by the shape and setal pattern of the flagellum. Bamazomus siamensis is very similar but has a longer and more acutely pointed dorsal process on segment XII, and a more elongate flagellum, posteriorly with lateral lobes as long as the central lobe – in B. serendipitus sp. n. the lateral lobes are shorter and less acute than the central lobe. Bamazomus pileti (Brignoli, 1974) (♀ unknown) is also very similar but can be distinguished by the flagellar setational pattern and having a more elongated flagellum.

Description

Female (Holotype: Coll. NHMD-223368)

Colour (live female: Fig. 2). General colour pattern light yellow brown. Chelicerae are reddish brown. Pedipalp dark reddish brown; dorsally on trochanter and dorsoproximal on femur slight bluish grey. Leg I femur dorsally bluish grey and otherwise mostly reddish or lacking pigment; terminal to femur reddish brown. Femur II, and III mostly unpigmented prolaterally, blueish grey-green dorsally and retrolaterally. Leg II and III terminal of femur mostly unpigmented. Leg IV femur bluish grey; terminal to femur mostly yellow brown, similar to posterior tergites; metatarsus and telotarsus reddish to unpigmented. Peltidial plates light yellow brown; propeltidium gradually increasingly reddish anteriorly, probably due to the colour of the pedipalps and chelicerae. Tergites brownish green and yellow brown, the posterior tergites more yellow and the anterior tergites with a more greenish tinge, the colour changing gradually between the posterior and anterior tergites. Flagellum is similar in colour to posterior tergites. Prosoma (Fig. 3c). Propeltidium with 11 setae arranged 2:1:2:2:2:2, the first pair of dorsosubmedian setae longer than the following pairs; the anterior margin of propeltidium produced to a sharp downward point between chelicerae; eyespots present, suboval to half circular. Mesopeltidium is widely separated. Metapeltidium is clearly divided. Anterior sternum subtriangular, longer than wide; anterior margin straight, anterior corners rounded; posteriorly pointed, reaching slightly posterior to the hind margin of coxa of leg II; with 19 setae, including 2 sternapophysial setae. Posterior sternum elongate triangular, with 7 setae.

Opisthosoma. Tergite I–VIII with a pair of Dm setae each; tergite I with 2 pairs of microsetae anteriorly, positioned diagonally with anterior pair closer together than the posterior pair, and tergite II anteriorly with 3 pairs of microsetae in a column; tergite IV with an additional single seta in the left Dl1 position; tergite V-VII with a pair of Dl1 setae positioned approximately the same distance from Dm setae as the two Dm setae are from each other; tergite VII with an additional single seta lateral to left Dl1; tergite VIII with pairs of Dl1 and Dl2 setae, the Dl1 closer to Dm setae than the two Dm setae are from each other. Tergite IX with pairs of Dl1 and Dl2 setae, and additionally with a pair of setae in between Dl1 and Dl2; the Dl2 setae longer than the other setae. Tergite X with a pair of Dl2 setae. Tergite XI with one pair of setae, placed more median than Dl2 on tergite X, and therefore assumed positioned as Dl1 setae. Tergite XII with pairs of Dm and Dl2 setae. The chaetotaxy formula of tergite I–XII, is 2+4 (microsetae diagonal):2+6 (microsetae in column):2:3:4:4:5:6:6:2:2:4. Sternite II (Fig. 4a), the genital plate, with the chitinized arch visible through the genital plate without dissection; with many scattered setae of various sizes; with 2 large lateral setae, on level with the posterior branch of the chitinized arch. Sternite III is very slim, with 2 rows of setae; posterolateral with 2 pairs of large setae. Sternite IV–VIII with 2 transversal rows of setae, very irregular on sternite IV, less on sternite V–VII; sternite IV–VII with 2 pairs of large posterolateral setae; sternite VIII with an anterior row of 8 setae and a posterior row consisting of setae pair Vm1, Vm2, Vl1B, Vl1A and Vl2. Sternite IX with setae pairs Vm1, Vm2, Vl1, Vl2; additionally with a pair of small setae between Vm2 and Vl1, the one on the right side placed anterior to the rest of the setae. Sternite X–XI with setae pairs Vm1, Vm2, Vl1, and Vl2; setae Vm1, Vm2 and Vl1 all distally bifurcated; Vl2 setae smaller than the other setae. Sternite XII with setae pairs Vm2, Vl1B, Vl1A, and Vl2, and a pair of thin hyaline setae between pairs Vm2 and Vl1B; setae Vm2, and Vl1B apically bifurcated. The most lateral dorsal, Dl2, and ventral setae, Vl2, on the opisthosomal segment XII are positioned very closely adjacent to each other. Sternite V–VII each with 2 apodemes, which are chitinized and distinctly darker than surrounding sternite, and more than 2 times wider than long.

Female flagellum with 3 flagellomeres, i.e. 2 annuli, flagellomere I longer than flagellomere II, and the terminal flagellomere about 4.8 times as long as flagellomere II (measured dorsally) (Fig. 5a-b).

Female genitalia (Figs 4a, 6, 7e). Spermatheca with 5 pairs of long spermathecal lobes, which are anteriorly directed; the lateral lobe on one side is basally bifurcated in the holotype; the single lobe can vary in length and in the holotype one of the median pairs of lobes are shorter than the rest; the lobes have external pores. The chitinized arch is hastate shaped sensu Monjaraz-Ruedas et al. (2019); the posterior branch is broadly U-like and the branches slim until they reach the internal angle; the anterior arch forms two large subtriangular plates, with the lateral tips reaching distinctly anterior to the internal angle, and is anteromedially divided, with the median tips turned posteriorly, creating a resemblance to a deep V-like anteromedian notch; the lateral tips well projected and sharp; the internal angle rounded. The gonopod is long and distinctly bifurcated distally.

Pedipalps. Trochanter strongly produced distally to a blunt tip, i.e. with an apical process; ventral margin with stout setae; mesal spur situated subdistally, on length with the ventral most part of the trochanter-femur joint; trochanter mesally with 4 setae in a diagonal row, the most distal seta positioned on the distal side of the mesal spur, and a 5th mesal seta is situated adjacent to the trochanter-femur joint. Femur dorsally with strong setae, and dorsoanterior with some weaker setae, otherwise with setae Fmv1, Fmv2, Fmv3, Fmv4, Fev1, Fev2, Fe1, Fe5, and Fed3 present; Fmv1, Fmv2, and Fmv3 situated closely adjacent to each other. Patella with 3 Pe setae, with some smaller setae more lateral to these; Pm with 3 setae; with Pme1 and Pmm3. Tibia with 5 setae in Ter; 2 setae in the Tm group, one small and one large; Tmr with 5 setae and Tir with 5 setae; Tir reaches further anterior and posterior to Tmr. Pm, Tmr, and Tir with setae that are white and plumose the terminal half. Tarsus with 2 spurs ventrodistally. Chelicera (Fig. 3a). Fixed finger with 2 large teeth, distally and proximally, and 4 smaller median teeth in between, the proximal large tooth with a small and very blunt lateral tooth on the distal side. The movable finger is rounded on the tip and distally curved; with a very blunt and broad median accessory tooth, with the tip proximally continuing almost straight into the ventral margin of the movable finger, about 1/3 of the movable finger's length from the tip, adjacent to the middle of serrula; serrula with 19 hyaline teeth; with a round distal guard tooth; lamella present, approximately half the length of the serrula, immediately distal to the accessory tooth. Setae group G1 with 3 spatulate setae, with the terminal 1/3 pedunculate, with short pilosity, and the proximal 1/3 stout. G2 with 5 setae. G3 with 5 setae. G4 with 4 setae. G5A with 11 setae, with short pilosity apically. G5B with 10 setae, becoming gradually shorter apically, apart from 2 proximal setae, which are much shorter; setae with short pilosity apically for most of their length. G6 with 1 smooth seta; the seta is about 0.6 times the length of the movable finger. G7 with 4 setae. Setal group formula: 3:5:5:4:11:10:1:4.

Legs. Telotarsus I with 6 segments; femur IV 2.96 times as long as wide.

Measurements of dimensions listed in Tab. 3.

Male (Paratype: Coll. NHMD-223368)

Colour (live male: Fig. 8). Generally lighter than the female. Leg IV patella and tibia bluish grey, metatarsus and telotarsus mostly unpigmented. Flagellum reddish brown.

Prosoma. Propeltidium with 11–13 setae (n = 3; Paratype with 13 setae) arranged 2:1:2:2:2:2(:2), the first pair of dorsosubmedian setae longer than the following pairs. Anterior sternum with 17 setae, including 2 sternapophysial setae. Opisthosoma (Fig. 7d). Tergite I–VIII with a pair of Dm setae each; tergite I with 2 pairs of microsetae anteriorly, positioned diagonally with anterior pair closer together than the posterior pair, and tergite II anteriorly with 3 pairs of microsetae in a column, with the middle pair more widely separated than anterior and posterior; tergite VII-VIII each sometimes with an additional single setae (left Dl1 present on tergite VIII on the paratype); tergite VIII with a pair of Dl2 setae. Tergite IX same as female, though sometimes an additional single seta is present. Tergite X and XI with pairs of Dl1 and Dl2 setae; tergite XI with an additional single submedian seta on the left or right side (present on the right side on the paratype). Tergite XII with pairs of Dm and Dl2 setae, the Dm setae are stout and bent. The chaetotaxy formula of tergite I-XII is 2+4 (microsetae diagonal):2+6 (microsetae in column):2:2:2:2:2-3:4-5:6-7:4:5:4. Tergite XII with a curvilinear triangular posterodorsal process. Sternite IX with setae Vm1, Vm2, Vl1, and Vl2; setae Vm1, Vm2, and Vl1 with bifurcated setae.

Male flagellum (Figs 7a-d, 9) is dorsoventrally flattened; the general shape is subrectangular; trilobed, with the median lobe triangular in shape and longer than the lateral lobes which are more rounded; in the centre, with a semi-circular ridge rounding anteriorly when viewed dorsally, approximately mirroring the shape of the median lobe; with a longitudinal lanceolate structure between the semi-circular ridge anteriorly and the median lobe posteriorly, laterally framed by convex longitudinal furrows. Setae pairs Dl2 and Dl3 positioned dorsoposteriorly on the lateral lobes, so closely adjacent that their bases are touching each other; Dm4 placed on the tip of the median triangular lobe; 7 smaller setae positioned posteroventrolaterally, and 3 small setae situated laterally on the plateau and slope to the lower posterior half of flagellum. Seta Vm1 is positioned immediately posterior to Vm2; setae Vm2 are situated approximately in line with the anterior margin of the flagellum, where it is sharply constricted to the stalk; Seta Vm1 is positioned immediately posterior to Vm2; setae Vm2 are situated approximately in line with the anterior margin of the flagellum, where it is sharply constricted to the stalk; Vm3 are situated in line with the posterior margin of the anteroventral depressions; Vm5 is situated between, or even slightly anterior to, Vl2; setae Vl1 is situated on the lateral edge of flagellum, between Vm3 and Vm5; Dm1 is positioned at level of the sharp constriction of flagellum to stalk. The flagellum (stalk included) is 1.59 times longer than wide.

Pedipalp (Fig. 5c). No obvious sexual dimorphism present; setation similar to female, apart from Pe seemingly with 2 setae and Tir with 6 setae.

Chelicera (Fig. 3b). G2 with 6 setae. The serrula on the movable finger with 21 hyaline teeth.

Legs. Femur IV 2.83 times as long as wide. Description otherwise similar to the female. Measurements of dimensions listed in Tab. 3.

Variation

Body length of female (4,98–5.60, n = 3) and male (4.29–5.09, n = 4). Number of propeltidial setae was found to vary between 11–13 in the male.The number of setae on both tergites and sternites was found to vary due to a presence of single and pairs of supernumerary setae.

Remarks

Newly moulted specimens appear very green, as was one presumably newly moulted juvenile specimen (JL13667). Juvenile B. serendipitus sp. n. specimens were separated from juveniles of S. portoricensis, the only sympatric short-tailed whipscorpion in RRTZ, by the divided metapeltidium, and propeltidium with 3 apical setae and more than 2 pairs of dorsosubmedian setae. The posterior branch of the chitinized arch was more widely opened and U-shaped before dissection (Fig. 7a), suggesting that the chitinized arch has been distorted during slide preparation. In some females tergite X and XI is only pigmented medially, and tergite XII and flagellum are mostly unpigmented. The barcodes of the female and male (JL13690) were identical, confirming their conspecificity.

Distribution

Only known distribution is the hothouses of RRTZ in Randers, Denmark. The native distribution is yet unknown. The geographic origin of the species is likely Southeast Asia, and possibly Thailand (see Discussion below).

Natural history

The specimens were found under stones and pieces of wood, in leaf litter, and on the soil, when removing leaf litter (Habitat: Fig. 10). They were mostly found on and in relatively dry soil and leaf litter in the Africa-dome and semi wet soil and leaf litter in the Asia-dome. Specimens were found in all three hothouse domes of RRTZ, in two of which it was found to be sympatric with Stenochrus portoricensis. When disturbed, one juvenile suddenly exhibited an odour resembling vinegar, which likely resulted from excreting acetic acid (Villarreal & García 2012).

Material examined listed in Tab. 4.

We report here the first records of Stenochrus portoricensis Chamberlin, 1922 from Denmark. The species identity was confirmed both morphologically, incl. the shape of the female genitalia (Fig. 12) and male flagellum, and molecularly, by comparing a COI-barcode with sequences on GenBank. Specimens belonging to this species were found in both RRTZ and OZ. In RRTZ the species was found in two of three domes, the South America dome and the Asia dome. No specimens were found in the Africa dome, despite it being closely connected to the Asia dome, in which S. portoricensis lives in sympatry with Bamazomus serendipitus sp. n. In OZ specimens of S. portoricensis were found in multiple areas within the hothouse Oceanium, one of which was a rare male (see Discussion). Specimens were found under leaf litter, stones, and pieces of wood, on semi wet soil.