Vellumnus tki, Ng & Clark, 2023
|
publication ID |
https://doi.org/ 10.1590/2358-2936e2023014 |
|
publication LSID |
lsid:zoobank.org:pub:31ABBD35-9781-4D92-82E7-A3BCF8BB61BF |
|
DOI |
https://doi.org/10.5281/zenodo.10955741 |
|
persistent identifier |
https://treatment.plazi.org/id/03C387F4-FFC2-B147-3B09-B86F23138152 |
|
treatment provided by |
Felipe |
|
scientific name |
Vellumnus tki |
| status |
sp. nov. |
Vellumnus tki View in CoL n. sp.
( Figs. 4–6 View Figure 4 View Figure 5 View Figure 6 )
Zoobank: urn:lsid:zoobank.org:pub:31ABBD35-9781-4D92-82E7-A3BCF8BB61BF
Material examined. Holotype: male (7.8 × 6.0 mm) (NHM 1932.7.7.22, ex 1893.11.3), Macclesfield Bank, South China Sea, coll. P.W. Bassett-Smith, 1893.
Diagnosis. Carapace relatively quadrate ( Figs. 4A View Figure 4 , 5A View Figure 5 ); setae on carapace evenly distributed, without ridges or vermiform patterns ( Figs. 4A View Figure 4 , 5A View Figure 5 ); setae on pereiopods covered with dense, short, soft pubescence almost completely obscuring margins and surfaces ( Figs. 4A View Figure 4 , 5A View Figure 5 ); epigastric, mesogastric, postorbital cristae low, gastric, subhepatic and branchial regions with on anterior margins ( Figs. 5A View Figure 5 , 6A View Figure 6 ); frontal margin convex, lateral lobe distinct, bilobed; supraorbital margin with distinct median fissure ( Figs. 5A View Figure 5 , 6A View Figure 6 ); external orbital tooth acutely triangular, anterolateral teeth relatively smaller, triangular, third tooth smallest, margins lined with small granules ( Figs. 5A View Figure 5 , 6A View Figure 6 ); anteroexternal angle of merus of third maxilliped angular but not auriculiform, ischium with shallow oblique sulcus ( Fig. 6C View Figure 6 ); outer surface of chelae with numerous round granules, vaguely arranged in longitudinal rows, carpus with numerous round granules, without distinct tooth on inner angle, fingers shorter than palm ( Figs. 4A, B View Figure 4 , 5B, C View Figure 5 ); ambulatory legs relatively short, without distinct crests or ridges; surfaces completely obscured by numerous setae( Figs.4A, B View Figure 4 , 5D View Figure 5 ); anterior thoracic sternum with surfaces relatively smooth, sternites 3, 4 fused with shallow groove and lateral sutures demarcating them ( Figs. 4B View Figure 4 , 6E View Figure 6 ); tubercle of sterno-pleonal locking mechanism rounded, on submedian part of sternite 5 ( Fig. 3F View Figure 3 ); male pleon relatively narrow; somite subrectangular, somites 1 and 3 subequal in width, telson subtriangular ( Figs. 4B View Figure 4 , 6F View Figure 6 ); G1 slender, sinuous, distal part bent laterally with subtruncate tip forming small flap on dorsal part ( Fig. 6H–I View Figure 6 ).
Etymology. This species is named for the High Commissioner of the Republic of Singapore, London, in gratitude for all his support of the natural history digital repatriation project between the Lee Kong Chian Natural History Museum, Singapore, and the Natural History Museum, London. His Excellency Lim Thuan Kuan is known as “TK” to his friends (pronounced “tee-kay”), and is the origin of “ tki ”.
Remarks. The holotype was examined by Heinrich Balss in June 1932 and identified as “? Lophoplax (Pilumnoplax) sculpta ”, but it is not this pilumnid species (see Takeda, 1977b; Maenosono, 2019; Ng and Rahayu, 2023). Instead, it is considered here to be an undescribed Vellumnus species.
In the relatively larger size, (ca. carapace width> 4–5 mm), a more quadrate shaped carapace, distinct carapace areolation, e.g., regions well demarcated, and relatively wider male anterior thoracic sternum, Vellumnus tki n. sp. is most similar to V. minabensis , but differs in that the carapace is more quadrate in shape, e.g., width to length ratio1.30; Figs. 4A View Figure 4 , 5A View Figure 5 (vs. carapace proportionately wider, e.g., width to length ratio 1.4 in V. minabensis ); the frontal lobe is convex; Figs. 5A View Figure 5 , 6A View Figure 6 (vs. frontal lobe strongly convex in V. minabensis ); the regions of carapace have scattered granules only on the anterior margins; Figs. 5A View Figure 5 , 6A View Figure 6 (vs. regions of carapace covered with numerous granules in V. minabensis ); the anterolateral teeth are proportionately smaller; Figs. 5A View Figure 5 , 6A View Figure 6 (vs. anterolateral teeth large and prominent in V. minabensis ); the granules on the carpus and chela are distinctly more dispersed; Fig. 5B, C View Figure 5 (vs. granules on the carpus and chela densely packed in V. minabensis ); and the ambulatory merus appears to be relatively shorter; Figs.4A View Figure 4 , 5D View Figure 5 (vs. ambulatory merus relatively longer in V.minabensis ; cf. Sakai, 1969: text-fig. 13; Sakai, 1976: text fig. 263, pl. 176, fig. 1). The G1 structures of the two species are similar, with the distal part slightly shorter with the tip more truncate in V.tki n. sp.; Fig. 6G–I View Figure 6 (vs. longer and more tapering in V. minabensis ; Sakai, 1969: text-fig. 12a) but this difference is not significant at the species level. The arrangement of setae on the carapace of V. tki n. sp. is also different from that of V. minabensis . Sakai (1969) described the setae on the carapace of V. minabensis as arranged in a “vermiform” manner ( Sakai, 1969: 266) but his original figure ( Sakai, 1969: text-fig. 13) does not illustrate this character. In a later color figure of the species, however, he showed the vermiform setal patten ( Sakai, 1976: pl. 176 fig. 1). This carapace setation pattern resembles that of V. labyrinthicus except that in V.minabensis , the carapace is proportionately wider and the anterolateral teeth are relatively weaker and directed obliquely anteriorly ( Sakai, 1969: fig. 13; Sakai, 1976: text fig. 263, pl. 176, fig. 1) (vs. carapace more quadrate, with the anterolateral teeth stronger and directed more laterally; cf. Ng, 2010: figs. 13A, 14A, 15A). The setae on the carapace of V. tki n. sp. are evenly distributed ( Figs. 4A View Figure 4 , 5A View Figure 5 ) and there are no ridges or vermiform patterns formed.
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.