Kurixalus inexpectatus Messenger, Yang, Borzee , Chuang & Othman, 2022

Messenger, Kevin R., Othman, Siti N., Chuang, Ming-Feng, Yang, Yi & Borzee, Amael, 2022, Description of a new Kurixalus species (Rhacophoridae, Anura) and a northwards range extension of the genus, ZooKeys 1108, pp. 15-49 : 15

Kurixalus inexpectatus Messenger, Yang, Borzee, Chuang & Othman sp. nov.

Holotype.

NJFU20180704001, an adult male (Fig. 9 , Table 1 ), collected by Yi Yang (YY) on a dirt road in Chuanbu Village, north of Changxing 57 m a.s.l. on 4 July 2018 (Fig. 9 ).

Paratypes.

Five adult males, NJFU20180704002 - 20180704006, collected by YY on 4 July 2018 at the type locality. One adult male, NJFU20180705001, collected by YY on 5 July 2018 at the same location. Five adult males, NJFU20180706001- NJFU20180706005 collected by YY on 6 July 2018 at the same location.

Type locality.

Chuanbu Village (川步村), Changxing County, Huzhou City, Zhejiang Province, People’s Republic of China.

Etymology.

The epithet inexpectatus is Latin for "the unexpected." This was chosen for several reasons. We selected this name because we had come to survey this region of China for different taxa. KRM came to this locale to survey for Megophrys . AB came to this locale to survey for Dryophytes . It was not only surprising to find this species while surveying for two other target genera, but upon realising the immense distance to the next closest population of Kurixalus , the discovery was even more unexpected. For an English and Chinese common name, we are recommending the name Changxing Treefrog (pronounced “Chang-shing” in English) 长兴原指树蛙 ( cháng xīng yuán zhǐ shù wā).

Diagnosis.

The specimen matched the genus Kurixalus , based on the following characters: tips of digits enlarged to discs, with circum-marginal grooves; small-body size; pointed snout, forming a beak-like appearance; serrated dermal fringes along the outer edge of the forearm and leg; an inverted triangular-shaped dark brown mark between the eyes; dorsal ") (" saddle-shaped marking; and a coarse dorsal and lateral surface with several small, irregular tubercles [7, 18, 29].

Comparisons.

Kurixalus inexpectatus sp. nov. is characterised and distinct from the majority of its congeners (19) by having a combination of being: (1) a small-sized species with an average adult size below 30 mm (in males); and (2) having two dark symmetrical pectoral blotches.

Genetically, the species is most closely related to K. idiootocus and is morphologically distinguished from this species by the combination of features: (1) having a tibio-tarsal articulation that extends beyond the anterior corner of the eye (versus the centre of eye); (2) having a significantly shorter snout relative to SVL; (3) a significantly greater internasal distance relative to SVL; (4) a significantly smaller eye diameter relative to SVL; (5) a nearly significantly wider tympanum diameter relative to SVL; (6) having a significantly greater distance between the eyes and the nares; (7) and by having a significantly longer forelimb length.

Description of holotype.

Adult male (SVL 29.4 mm); head width about the same as body, its length 37.9% of SVL; head slightly longer than wide in the holotype (11.1 mm vs. 11.0, respectively); snout pointed and slightly turned down, forming a small “beak-like” appearance typical in many rhacophorids; eye large, protuberant, ED 36.3% of HDL, 13.8% of SVL; pupil horizontal; tympanum distinct in form, but not distinct in texture or colour, its diameter 6.8% of SVL; nostrils protuberant; closer to the tip of the snout than the eye; vomerine teeth absent; tongue notched posteriorly; single internal vocal sac.

Relative length of fingers I <II <IV <III. Tips of all four fingers form discs with circum-marginal and transverse ventral grooves; relative width of discs is IV> III> II> I; nuptial pads absent; fingers lacking webbing at base; subarticular tubercles prominent and rounded; series of tubercles forming serrated dermal fringe along outer edge of forearm.

Heels overlapping when legs at right angle to body; relative length of toes is I <II <III <V <IV; toes moderately webbed at base; tips of toes expand to form discs with circum-marginal and transverse ventral grooves; toes discs are smaller than finger discs; relative size of toe discs I <V <IV <III <III; subarticular tubercles present, but not as obvious as hand.

Body is covered in numerous tubercles and dermal ridges. Ridges are present on the dorsum, but absent from the flanks and venter; tympanum also covered in tubercles.

Measurements of holotype (in mm).

The average of three measurements for each character is as follows: SVL 29.4, HDL 11.1, HDW 11.0, SNL 3.8, IND 3.3, IOD 3.3, UEW 3.1, ED 4.0, TD 2.0, TEY 0.9, DNE 2.7, FLL 15.7, THL 13.4, TL 14.5, FL 12.9, HND 9.1, RAD 6.7.

Colouration of holotype in life.

Light brown dorsum with white patch in the sacral region and extending a bit on to the femurs. Darker brown ") (" dorsal saddle. Ventrally, white chest with brown colouration in the pectoral and axillary region. Ventral side of forelimbs have streaks of white and brown, almost like a marbled appearance. Ventral side of hind-limbs orange in the thigh and tibia region has the same brown and white marbled appearance present in the forelimbs. Palm of hand primarily light brown; sole of feet slightly darker than hand.

Colouration of holotype in preservation.

In preservation, the orange and light brown colours have faded, the darker brown has darkened compared to life. Pattern same as in life. Iris clouded. Chest white, throat black. Ventral side of arms black and white marbled appearance. Ventral side of tibia black and white marbled, similar to ventral aspect of forelimbs.

Variation.

As the holotype and paratypes of the new species are all male, sexual dimorphism cannot be ascertained. Aside from SVL, which is to be expected, the next characters which showed the greatest variation were FLL, TL, FL and TFL. Though the holotype has a head length longer than head width, most specimens had a head length shorter than head width. Colour varied between individuals, likely induced by temperature and/or time of day, as we observed this change first-hand. See Table 8 for variation amongst all specimens.

Description of eggs and tadpoles.

We did not find any eggs or tadpoles despite being present during the breeding season.

Distribution and ecology.

Kurixalus inexpectatus sp. nov. has been found calling as early as 26 April. Males would call from shrubs approximately 20 to 160 cm above temporary pools in and along roadside ditches. Temporary pools were 15 cm deep and up to 8 m long. In April, only sparse numbers of individuals were found calling. In July, full choruses could be heard, yet no individuals were found engaged in amplexus. No females have been found.

The vegetation primarily consisted of shrubs and secondary broad-leaved forest. No specimens were found in the adjacent bamboo forest.

Distribution.

Currently, the species is only known from the type locality, on the outskirts of the Wizard of Oz resort in Chuanbu Village, Changxing County, Huzhou City, Zhejiang Province, China. Surveys were made in the surrounding mountains for additional populations without success, including mountain ranges in Anhui and Jiangsu Provinces. The resort is situated at the southeast edge, in a northwest-to-southeast valley lower than 100 m in elevation. A creek comes from the hills, into a reservoir, which then flows about 2 km along the valley through the extent of the resort. The area was intended to be a plantation (unconfirmed, but suspected to be bamboo, based on the number of surrounding bamboo plantations), but in 2013, the land was set aside for the resort (pers. comm.). Now the resort consists of tea plantations, peach orchards, well-manicured grasses, a bamboo forest and miscellaneous shrubbery.

Figures

Figure 9. Holotype of Kurixalus inexpectatus sp. nov. A dorsal view B ventral view C right hand, ventral view D right foot, ventral view E dorsolateral view.