Trachyjulus magnus, Likhitrakarn & Golovatch & Jeratthitikul & Srisonchai & Sutcharit & Panha, 2020
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publication ID |
https://dx.doi.org/10.3897/zookeys.925.49953 |
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publication LSID |
lsid:zoobank.org:pub:A531C6A9-F7A8-4747-B4DB-A18D00237417 |
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persistent identifier |
https://treatment.plazi.org/id/620CFB43-417C-4A18-A946-8DC27A5567B2 |
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taxon LSID |
lsid:zoobank.org:act:620CFB43-417C-4A18-A946-8DC27A5567B2 |
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treatment provided by |
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scientific name |
Trachyjulus magnus |
| status |
sp. nov. |
Trachyjulus magnus sp. nov. Figures 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4
Type material.
Holotype ♂ (CUMZ), Thailand, Surat Thani Province, Ban Na San District, Wat Tham Khrom Wanaram, 8°46'12.07"N, 99°22'6.36"E, 16.06.2018, leg. W. Siriwut, E. Jeratthitikul and N. Likhitrakarn.
Paratypes. 15 ♂, 20 ♀ (CUMZ), 1 ♂, 1 ♀ (ZMUM), 1 ♂, 1 ♀ (NHMD), same locality, together with holotype.
Name.
To emphasize the largest body size of this species compared to all other species known in the genus.
Diagnosis.
This new species differs from all other Trachyjulus spp. by the largest body size (43.5-64.2 mm long, 2.1-2.8 mm wide), and also from the particularly similar and grossly sympatric T. unciger (23-42 mm long, 1.2-2.0 mm wide) in having the tegument of rings 2 and 3 nearly smooth (vs evidently carinate), carinotaxic formulae of typical rings (11-8/11-8+I/i+2/2+m/m vs 8-6/8-6+I/i+2/2+m/m), combined with the number of ommatidia (5-6+5-6 vs 4+4), and the posterior gonopods showing medial coxosternal processes (mcp) subtrapezoid (vs shorter and lobe-shaped).
Description.
Length of holotype ca 62.5 mm (Fig. 1A View Figure 1 ) and that of paratypes 44.1-64.3 (♂) or 43.5-64.2 mm (♀); midbody rings round in cross-section (Fig. 2I View Figure 2 ), their width (horizontal diameter) and height (vertical diameter) being similar; width of holotype 2.6 mm, of paratypes 2.1-2.7 (♂) or 2.1-2.8 mm (♀).
Coloration of live animals red-brown to yellow-brownish (Fig. 1 View Figure 1 ), venter and legs brownish yellow to yellowish, antennae light to pale yellowish, eyes blackish, a thin axial line traceable; coloration in alcohol, after one year of preservation, similar, but body yellow-brownish to light brownish, vertex red-brown to light brown, eyes blackish to brownish.
Body with 80p+2a+T rings (holotype); paratypes with 68-86p+1-3a+T (♂) or 69-93p+1-4a+T (♀) rings. Eyes large, flat, ovoid, with 6(5)+6(5) ommatidia arranged in a single vertical row (Fig. 2D View Figure 2 ). Antennae short and clavate (Figs 2A, B, D, F View Figure 2 , 5A View Figure 5 ), extending past ring 4 laterally (♂, ♀), with four evident apical cones (Fig. 2G View Figure 2 ), antennomeres 5 and 6 each with a small distoventral group or corolla of bacilliform sensilla (Figs 2F, H View Figure 2 , 5A View Figure 5 ). Clypeus with five teeth anteromedially (Fig. 2E View Figure 2 ). Gnathochilarium oligotrichous, mentum single (Figs 2E View Figure 2 , 4B View Figure 4 ).
In width, head = ring 2 <ring 4 = 5 <3 <6 <7 <8 <9 <10 <collum = midbody ring (close to 12th to 14th); body abruptly tapering towards telson on a few posteriormost rings (Fig. 2B, O View Figure 2 ). Postcollar constriction evident, but not particularly strong (Fig. 2B View Figure 2 ).
Collum (Fig. 2A-C View Figure 2 ) smooth, only near lateral edges with 2-4 light, short, superficial striae (Fig. 2A-C View Figure 2 ). Rings 2 and 3 nearly smooth, with 6-9 light, superficial striae (Fig. 2A, B View Figure 2 ). Following metaterga clearly and rather strongly carinate (Fig. 2A, B, N, O View Figure 2 ), especially so from ring 5 on, whence porosteles commence, these being completely absent from legless rings where ozopores are missing (Fig. 2A View Figure 2 ). Porosteles large, but low, conical, round, directed caudolaterad, broader than high (Fig. 2L View Figure 2 ). Carinotaxic formula of metaterga 4, 10-11/10-11+m/m (Fig. 2A, B View Figure 2 ). Carinotaxic formulae of following rings typically 11-8/11-8+I/i+2/2+m/m (Fig. 2A, B, N, O View Figure 2 ); all crests and tubercles, including porosteles, low. Tegument smooth (Figs 1 View Figure 1 , 2A, B, N, O View Figure 2 ), shining throughout. Fine longitudinal striations in front of stricture between pro- and metazonae, remaining surface of prozonae very delicately shagreened (Fig. 2A, B, M-O View Figure 2 ). Metatergal setae absent. Rings 2 and 3 each with long pleural flaps. Midbody ring nearly round in cross-section (Fig. 2I View Figure 2 ).
Epiproct (Fig. 2N-P View Figure 2 ) simple, bare, smooth, regularly rounded caudally. Paraprocts smooth, regularly convex and densely setose (Fig. 2P View Figure 2 ). Hypoproct as usual, transversely bean-shaped, slightly concave caudally (Fig. 2P View Figure 2 ).
Ventral flaps behind gonopod aperture on ♂ ring 7 barely distinguishable as low swellings, forming no marked transverse ridge.
Legs short, on midbody rings about 2/3 (♂, ♀) as long as body height (Figs 2I, J View Figure 2 ). Claw at base with a strong accessory spiniform claw almost half as long as main claw (Fig. 2K View Figure 2 ). Tarsi and tarsal setae very delicately fringed.
♂ legs 1 highly characteristic (Figs 3A, B View Figure 3 , 4C, D View Figure 4 ), with a strongly enlarged, long, slim, central hook (actually a pair of very tightly adjacent) curved forward (Figs 3B, C View Figure 3 , 4C View Figure 4 ), and strong, high, densely setose, triangular, 1-ringed telopodites (Figs 3A, B View Figure 3 , 4E, F View Figure 4 ).
♂ legs 2 (Figs 3C, D View Figure 3 , 4E, F View Figure 4 ) slightly enlarged, with high and large coxae; telopodites hirsute on anterior face; penes subconical, rounded apically, fused at base, bare.
♂ legs 3 (Figs 3E View Figure 3 , 4H View Figure 4 ) slightly reduced, modified in having coxae especially slender and elongate.
Anterior gonopods rather simple (Figs 3F-H View Figure 3 , 4I, J View Figure 4 ), with 1 or 2 strong apical setae on subtrapezoid, medial, coxosternal processes (mcp); telopodites (te) club-shaped, curved, sparsely setose, nearly as high as lateral coxosternal process (lcp), the latter slender and long, placed basal to telopodites. Anterior parts of lateral coxal processes and telopodites rod-shaped, slender and digitiform, with apicolaterally denticulate tips (Fig. 3H View Figure 3 ).
Posterior gonopods (Figs 3I-L View Figure 3 , 4K, L View Figure 4 ) highly compact, coxites well separated from sternum, fused only basally, with a parabasal field of coniform microsetae caudally, each with a setose, paramedian, coxal process (pp) (Figs 3I View Figure 3 , 4L View Figure 4 ); telopodites (te) high, distally microserrate/papillate (Fig. 3K, L View Figure 3 ); anterior coxal processes (ap) elongate, shorter than telopodites, densely setose and rounded distally (Figs 3I-K View Figure 3 , 4K, L View Figure 4 ); both divided by a very high, axe-shaped flagellum (f) (Figs 3I, J View Figure 3 , 4K, L View Figure 4 ).
Remark.
The often striking colour difference between head+collum+ring 2 and the remaining rings observed in SEM micrographs (Fig. 2 View Figure 2 ) is certainly an artifact resulting from unwanted electrical charging.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.