Megophrys ombrophila, Messenger & Dahn & Liang & Xie & Wang & Lu, 2019

Messenger, Kevin R., Dahn, Hollis A., Liang, Yuanrui, Xie, Peng, Wang, Yong & Lu, Changhu, 2019, A new species of the genus Megophrys Gunther, 1864 (Amphibia: Anura: Megophryidae) from Mount Wuyi, China, Zootaxa 4554 (2), pp. 561-583 : 575-579

Megophrys ombrophila sp. nov. Messenger & Dahn

Holotype. Adult male, WUYI2014101 , collected by Kevin R. Messenger and Hollis A. Dahn (hereafter KRM and HAD, respectively) on 16 June 2014, from a bamboo plantation ( Fig. 8 ) outside Guadun village , Wuyishan National Nature Reserve (27.735980°N 117.640810°E, 1242 m above sea level), Wuyi City, Fujian Province, China.

Paratypes. Nine adults (4 males, 4 females, 1 unknown): Two adult males, WUYI2014102 and WUYI2014103 , collected from the same locality as the holotype at 1257 to 1302 m a.s.l. by KRM and HAD on 16– 17 June 2014; an adult male, NJFU2015201 , collected by KRM on 27 May 2015 in tea plantation, about 50 m from bamboo forest edge; an adult male, NJFU2015202 , collected by KRM on 28 May 2015, found on rocky path/ ephemeral stream in secondary bamboo forest; an adult female, WUYI2014104 , collected by KRM and HAD, from an abandoned tea plantation near (0.6 km linear distance) the type locality at 1262 m a.s.l. on 17 June 2014, 27.7317 117.6366; an adult female, NJFU2015203 , collected by KRM on 30 May 2015 on footpath between tea plantation and bamboo forest; an adult female, NJFU2015204 , collected by KRM on 1 June 2015 north and west of Guadun village in bamboo plantation, representing the northern and western most find as well as the highest elevational record at 1350 m a.s.l. ; 1 adult female, WUYI2015101 , collected by KRM and HAD on 23 June 2015, found after a rainstorm; 1 specimen of unknown sex, NJFU2015205 , collected by KRM on 27 May 2015, was killed on the road that leads into Guadun village at 27.734 117.646, which also represents the easternmost and lowest elevation find at 1125 m a.s.l.

Etymology. Megophrys ombrophila: Greek : ombros (rainstorm), Greek: philos (that loves, that is fond of), in reference to the species’ propensity for being especially active during and after heavy rainstorms. For an English and Chinese standard name, we are recommending the name Yu Shen Horned Toad/ Yǔ Shén jiǎo chán (ÑṖƦǿ), after the Chinese god of rain.

Diagnosis. The specimen matched the genus Megophrys based on the following characters: head broad and depressed, tympanum distinct, tubercles present on upper eyelid, tubercles present on the chest, vertical pupil, supratympanic fold present and distinct, no mid-dorsal fold, and a lack of black spines on the dorsum ( Fei et al. 2009). Megophrys ombrophila sp. nov. is characterized by the combination of the following characters: (1) a smallsized species with 27.4.0–34.5.0 mm SVL in adult males and 32.8–35.0 mm SVL in adult females; (2) head length slightly shorter than head width (HDL/HDW ratio ranges from 0.85–1.00:1); (3) snout rounded in dorsal view, slightly protruding, sloping backward to mouth in lateral view, protruding beyond the mandible; (4) canthus rostralis developed; (5) tympanum large and distinct, TMP/EYE ratio ranging from 0.53–0.69:1; (6) vomerine teeth absent; (7) heels of the feet not meeting when femurs are held at 90° to the axis of the body and tibias are depressed against the femur; (8) tibio-tarsal articulation reaching forward to the posterior corner of the eye; (9) tibia relatively short, TIB/SVL ratio ranging from 0.33–0.41:1; (10) relative finger length I <II <IV <III; (11) toes lacking webbing; (12) distinct subarticular tubercles at the base of each finger; (13) dorsal skin mostly smooth with scattered granules and ridges; (14) triangular ridge with small granules between the eyes; (15) a Y-shaped dorsal ridge with granules; (16) horn-like tubercle on posterior edge of eyelid, distinct but small; (17) supratympanic fold distinct and well-developed, extending to scapula; (18) throat possessing a single short streak down the midline, darker in color than surrounding tissue.

Description of holotype. An adult male ( Fig. 9 A-F), 27.4 mm SVL; head wider than long, with HDW/HDL ratio being 1.2:1; snout rounded in dorsal view, slightly protruding in lateral view, snout protruding beyond the mandible, sloping backward to mouth; top of the head flat; eye diameter 34% of HDL, pupil vertical; nostril oblique ovoid; canthus rostralis well developed, forming the beginning of a fleshy, protruding ridge, that continues over the upper eyelid, and transitions into a supratympanic fold that terminates in the scapular region; internasal distance slightly longer than interorbital distance; tympanum distinct and large, EYE/TMP ratio 1.7:1; ovoid choanal slit at base of maxilla; vomerine teeth and ridge absent; maxillary teeth present; tongue margin smooth, not notched from behind.

Radioulna length is 19.8% of SVL; hand without webbing, hand length measuring 21.3% of SVL; fingers without lateral fringes, relative finger length I <II <IV <III; tips of fingers slightly dilated, with rounded tips; subarticular tubercle at base of each finger; inner metacarpal tubercle enlarged, outer metacarpal tubercle smaller, both reddish in color. Hindlimbs slender, tibio-tarsal articulation reaching forward to the posterior corner of eye; heels not overlapping when tibia depressed against femur; tibia and foot measuring 36.7% and 59.5% of SVL respectively; relative toe length I <II <V <III <IV; toe tips rounded and slightly dilated, without webbing; toes without lateral fringes or subarticular tubercle; inner metatarsal tubercle short and ovoid, reddish in color, outer metatarsal tubercle absent.

Dorsal skin rough; several granules throughout the body, from the top of the head, the dorsum, the flanks, and the dorsal side of limbs. Granules on the flanks are larger than granules elsewhere. Large, distinct tubercles along the edge of the upper eyelid; series of small granules on dorsum running parallel to body axis. Ventral surface smoother than dorsal surface but still has presence of small granules; ventral thigh mostly smooth, with several small femoral glands towards the posterior aspect of thigh; pair of small, white pectoral glands on chest.

Measurements of holotype (in mm). SVL 27.38, HDL 9.35, HDW 10.84, SNT 2.8, IND 3.46, IOD 2.7, EYE 3.22, TMP 1.87, TEY 1.9, HND 5.84, RAD 5.42, FTL 16.29, TIB 10.05.

Coloration of holotype in life ( Fig. 9 A–B). Dorsal color light brown with dark brown “Y”-shape. The fork of the “Y” comprised of a raised ridge. Lateral to the ridges of the “Y” are dorso-lateral ridges running lengthwise. Dark brown interorbital triangle, two corners over each eye and third corner pointing posteriorly form the darkest aspects of the triangle. Center of triangle is slightly lighter brown in color, more like the background coloration. Dorso-laterally, the light brown of the dorsum transitions to orange on the venter. Venter is mostly light tan and orange with dark brown stripes running parallel to the body axis. A prominent stripe running down the center of the throat to the chest. Pectoral and femoral glands white. Iris of eye is a golden brown to auburn coloration. Dark subocular stripe from the eye to lip. Another dark post-ocular stripe running from the eye to the tympanum. Dark crossbars running perpendicular to the radioulna, thigh, tibia, and feet. The granules that are found throughout the body can vary from red, brown, black, and white in color. Tubercles at the base of each finger are mottled white and brown ( Fig. 9C ) and tubercles at base of hand are red. The subarticular tubercle on the feet are small, ovoid, and reddish in color ( Fig. 9F ). The rest of the sole of the foot is brown.

Coloration of holotype in preservation. Preservation caused increased contrast in specimen compared to life. Light tan fades to lighter tan on dorso-lateral surface. The dark brown patterning turns darker. A reticulate pattern emerges. The dark corners of the interorbital triangle are the most prominent and the inner aspect of the triangle is closer to the background coloration. On the ventral surface, the groin is white, chest is mostly grey with black stripes running parallel to body axis. Presence of crossbars running parallel to the radioulna, thigh, tibia, and feet still present, as they were in life. Subocular and post ocular stripe present in life are still present in preservation. Pectoral and femoral glands white.

Variation. There is variation in morphometric measurements of the type series ( Table 5). In nearly all measured criteria, females are larger than males. The only measurement in which females had a value less than males was in the average TEY distance. There is much variation in color. Majority of specimens were orange or yellow-orange in color, but other colors include slate grey, light brown, and dark brown. The dark brown coloration is usually temporary (likely temperature induced) as these dark brown individuals lighten in captivity within a few hours. Under preservation, most specimens retained the lighter coloration, making dorsal patterns more visible. Some specimens have dorsal granules that create a “V” shape, others simply have granules that run in parallel series to the body. Dorsal pattern most commonly gives the impression of a “Y,” but can also appear as a square, a “V,” or an “X.” Figure 10 displays several examples of the variation in dorsal patterning.

Secondary Sexual Characteristics: Males have a single subgular vocal sac. Males collected lacked nuptial pads or spines, and lacked any fleshy projection above the cloaca, but since our specimens were presumably

sampled outside of the breeding season, this may be the reason. Sexes of males and females were determined through inspection of the gonads via dissection.

Distribution and Ecology. We observed 25 individuals total (6 male, 4 female, 15 unknown), all through active search methods. Save for one presumably roadkilled individual, all specimens were active in habitat. No eggs or tadpoles were observed despite search efforts. Currently M. ombrophila sp. nov. is only known from the outskirts of Guadun village (within 1 km of the town). Based on the supposedly preferred habitat and elevational range in which we found specimens, the species should have an approximate distribution of 173 km 2 within the Wuyishan National Nature Reserve on the Fujian side of the reserve, but there is no reason for it to not be found on the Jiangxi side of the reserve. Five of the specimens were found in a bamboo plantation near the village. During surveys that yielded M. ombrophila sp. nov., the species was found in syntopy with Megophrys boettgeri, Theloderma rhododiscus Liu & Hu, and Leptobrachium liui Pope. We never found the species syntopic with M. kuatunensis , though Jianhuan Yang (JHY) did observe a calling male M. ombrophila syntopically with M. kuatunensis in mid-May. Two individuals were found in an abandoned tea plantation surrounded by bamboo plantation and secondary forest. Another specimen was found dead on the road (presumably ran over by a car) at the edge of a bamboo plantation. In general, the species was most commonly found in edge habitat, between bamboo forest (including bamboo plantations) and mixed broad-leafed evergreen forest. Common vegetation and tree species include Moso bamboo ( Phyllostachys edalis ), Long-ear Cane bamboo (Indocalamus longiauritus), Masson Pine ( Pinus massoniana ), Chinese fir ( Cunninghamia lanceolate ), Tea tree ( Camellia sinensis ) and Chinese cedar ( Cryptomeria fortunei ).

Several individuals (n=4) were found in an active tea plantation, but in all cases, the tea plantation was small (<1 ha) and surrounded by bamboo forest. Specimens were never more than 70 m from bamboo edge. One specimen was found in a secondary forest. Three specimens were found in secondary bamboo forest (nonplantation) that was comprised mostly of Long-eared Cane Bamboo, Moso Bamboo, and sparse hardwoods. Eight specimens were found on the edge habitat between a Long-eared Bamboo Forest and tea plantation. No specimens were found within the city limits of Guadun village.

Provenance of finds ranged from 1125 to 1350 m, with an average of 1242 m (SD + 39.7 m; n=25). JHY found the one and only calling male (not collected) on 18 May 2012. The species is more active and detectable during rain events. Of our 55 days of sampling effort, 28 (51%) were days with rain and 27 (49%) had no rain for at least 24 hours. In May 2015, during nights of rain events, each night yielded 5– 7 specimens. One day post rain yielded 2– 3 specimens, and any day beyond 2-days post rain did not yield any specimens. Nighttime temperatures of finds averaged 20.5 (SD + 0.8, range 19.2–22.3°C, n=23), with an average humidity of 92.3 (SD + 4.7, range 86.3–98.9, n=23), and barometric pressure averaged 25.8 (SD + 0.1, range 25.57–25.93, n=23).

There have not been surveys for this species outside of May, June, and July. We cannot confirm the mating season. Initially we thought the specimen calling on 18 May 2012 was likely calling toward the beginning of the breeding season, and efforts were made to find calling males during the second half of May in 2014 and 2015, but as none were found, despite finding several individuals each night, we now suspect that before the 18 th of May is around the end of the breeding season for this species. It is our recommendation that for future surveys for this species, especially for parties interested in the breeding ecology that surveys for breeding males begin around March and conducted to mid-May. It would also be of interest to see if the species is present on the Jiangxi province side of the reserve.

Regarding activity, one specimen (HM 208556) was found in the day time (15:47 on 14 June 2013, a rainy day) and 24 specimens were found at night. Nocturnal animals were found as soon as 49 minutes after sunset, to as late as 4 hours 2 minutes after sunset. A higher number of specimens were found immediately after heavy rains, and only a few specimens were found during heavy rains.

Megophrys ombrophila sp. nov. does not currently face excessive threats. It is not of economic concern, so there is no worry about the species being used for consumption, medicine, or a high demand for the pet trade (prior to our distinction/ recognition, none of the locals recognized it as being different from all the other “small frogs”). Within the Wuyishan nature reserve, the biggest threat is that of habitat destruction. The species is semi-tolerant of disturbance, seeming to prefer mildly disturbed areas to less disturbed. Mild disturbance in this context is referring to the creation of a trail through the woods, or a small (<1 ha) tea plantation.

Figures

FIGURE 8. Habitat of type locality, a bamboo plantation, 0.5 km east of Guadun village.

FIGURE 9. A. View of the adult male holotype WUY2014201 of Megophrys ombrophila sp. nov. in life, among leaf litter. B: Dorsolateral view of the holotype in life. C: Hand of the holotype. D: Dorsal view of holotype in preservation. E: Ventral view of holotype in preservation. F: Foot of the holotype. G: Close up view of supraocular tubercles and supratympanic fold (HM 208556). H. Phenotypic variation within the species (WUYI2014102). I. Specimen found by JHY (HM171540) in May 2012.

FIGURE 10. Examples of variation in the dorsal pattern, which usually resembles a “Y” or asymmetrical “X.” Clockwise from upper left: specimen #: HM208970, NJFU2015201, WUYI2015101, HM208971, HM208972.