Callulina meteora, Menegon, Michele, Gower, David J. & Loader, Simon P., 2011

Menegon, Michele, Gower, David J. & Loader, Simon P., 2011, A remarkable new species of Callulina (Amphibia: Anura: Brevicipitidae) with massive, boldly coloured limb glands, Zootaxa 3095, pp. 15-26 : 16-22

publication ID	https://doi.org/ 10.5281/zenodo.202448
DOI	https://doi.org/10.5281/zenodo.5667402
persistent identifier	https://treatment.plazi.org/id/870D0F51-3A60-FFF5-72FA-C1D14F7018D4
treatment provided by	Plazi
scientific name	Callulina meteora
status	sp. nov.

Treatment

Callulina meteora View in CoL sp. nov.

( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , 5–7 View FIGURE 5 View FIGURE 6 View FIGURE 7 ; Table 1 View TABLE 1 )

Callulina sp. 1 Menegon et al. (2008: p.114, appendix 1, tables 3, 4).

Holotype. BMNH 2008.450 (Field tag MW 6825) a mature female ( Fig. 1 View FIGURE 1 ). Collected from the Maskati side of the Nguru South Forest Reserve, Tanzania, 6.069027778 S - 37.50066667 E, 1980 m ( Fig. 6 View FIGURE 6 ) by David Gower, Roy Hinde, Simon Loader, Hendrik Müller, Maria Müller, and Mark Wilkinson in January 2008.

Paratypes. MTSN 8129-8134 ( MTSN 8134, 39 ova in vitellogenesis; MTSN 8130 cleared and stained), MTSN 8141, collected by Michele Menegon between October 26 and November 0 2, 2004 in the Nguru South Forest Reserve, 6.06630176 S - 37.49802743 E, Nguru Mountains, Morogoro Region. Tanzania. BMNH 2008.118- 451-452-453-454-455-456-457-458-459-460-461-462-463-464 same collection data as holotype.

Diagnosis. The species is assigned to Callulina within Brevicipitidae based on the following morphological features: Moderately sized wedge-shaped lobes on the mentomecklian elements, posteroventrally directed (variably reduced/enlarged in Probreviceps , Balebreviceps , and Breviceps , see Largen & Drewes 1989); cultriform process of the parasphenoid with broad base but narrow alary processes, tapering laterally (cultriform process of the parasphenoids widely variable in breviciptids, Largen & Drewes 1989); nasals almost meet at midline (broadly separated in Breviceps and Balebreviceps ); clavicle well-developed and straight though slightly curved anteriorly at the point of contact between coracoid and scapulae (clavicle straight in Breviceps , Probreviceps , Spelaeophryne ); omosternum large (rudimentary or small in Breviceps , Probreviceps , moderate in Balebreviceps ); tympanum present and usually well-differentiated (absent in Balebreviceps and Probreviceps uluguruensis ); double condylar articulation between the urostyle and the sacral vertebrae (fused in Balebreviceps , Breviceps , and Probreviceps ); truncated terminal phalanges (simple in Spelaeophyrne, Probreviceps , Breviceps , and Balebreviceps ); single posterior denticulated row in the palate of Callulina (two denticulated rows in Probreviceps , glandular mass in Breviceps ).

Callulina meteora is morphologically distinct from most other species of Callulina ( C. kreffti , C. kisiwamsitu , C. dawida , C. kanga , C. laphami and C. stanleyi ) in having large glands on the limbs. The new species is distinguished from C. shengena and C. hanseni (also with enlarged limb glands) by the presence of a tympanum (absent in C. shengena ) and limb glands that are distinctly differently coloured to the rest of the limbs (no distinctive gland colour in C. hanseni ).

Description of holotype. Female. Body stout, head short but as wide as body. Snout truncate in lateral view, snout-tip extending slightly beyond upper and lower jaws. Snout tip rounded at edges, flattened not pointed at apex. Canthus rostralis rounded. Dorsal aspect of head covered by small, rounded, irregular-shaped warts. Ventral region with larger, granular like warts on chin and underside. Eyelids smooth with very small irregular shaped warts. Pupil was horizontal before preservation. Tympanum distinct, suboval (not as tall as long), smooth, with granular warts on slightly raised rim around edge of disc. Dorsum of body with small, irregular glandular masses giving warty appearance. Ventral surface with larger irregular shaped glandular masses, slightly larger and more granular on flanks. Forelimb slender. Massive continuous glands covering dorsal and ventral aspects of forearm. Surface of massive arm gland with smaller, irregular, slightly smoother bumps. Webbing almost absent on hand, only marginal rudimentary skin joining each finger. Distal phalanges moderately long, thick, truncate, expanded only slightly, rounded at edges. Inner tubercle smaller than outer tubercle, separated by a mid-palmar tubercle. First finger shortest, followed by second, fourth, third. Tubercles darker than silvery/metallic background of hand. Hind limbs stout, tibia, metatarsus and carpal area of tarsus covered by an enlarged glandular mass. Distal phalanges of feet moderately long, thick, truncate, expanded only slightly, rounded at edges. First toe marginally the shortest, followed by second, third, fifth, fourth. On toes and fingers, terminal phalanx darker, with a fold of skin, marked by a white line at the dorsal junction between the penultimate and ultimate phalanges. Webbing almost absent on foot, only marginal rudimentary skin joining each toe. Inner and outer tubercle in contact, equal in size. Vent ventro-posteriorly positioned.

Measurement of holotype. SUL = 38.2; TL = 13.5; ED = 4.2; TD = 2.0; ETD = 2.2; ND = 2.5; NED =2.8; JW = 13.8; LF3 = 4.4; LT4 = 5.7, TSL = 11; HL = 12.1; NLD =1.7; WDF3 = 1.3; WDTF3 = 1.2; IOD = 6.1.

Colour. In preservative, the holotype dorsal ground colour is pale grey/brown, with darker brown patterning as irregular lateral dorsal markings. The flanks are a paler grey/brown. The dorsal and ventral surfaces of the thighs are dark brown, contrasting strongly with the silvery/metallic colouration of the glands. The ventral surface of the body is cream, with a dark brown colouration on the lateral edges. In life, the holotype has the same patterning as in preservative but with more vivid colours. The massive glands on the limbs are silvery, giving a striking metallic sheen to the surface (see Fig. 2 View FIGURE 2 ).

Variation. The tympanum is usually distinct in Callulina meteora , but in some paratypes (BMNH 2008.464, BMNH 2008.453-455, BMNH 2008.461, BMNH 2008.451) it is poorly demarcated and was measured by dissecting the skin around the region. Otherwise there is little notable (non-colour) morphological variation among individuals apart from between the sexes. Males are significantly smaller in body length (T-test: <0.05, females, SUL= 34.8–40.6 mm, x= 41.55 mm, number= 8; males, 26.5–35.4 mm, x= 30.1 mm, number= 9), and head width (T-test: <0.05). All other morphological characters analysed are not significantly different between the sexes.

Colour variation. Callulina meteora individuals show wide colour variability with some rather constant patterns. In all examined individuals, the massive limb glands are paler than surrounding areas, often whitish or silvery with, as in the rest of the body, a metallic sheen (see Fig. 2 View FIGURE 2 ). The body can be almost completely white or coppery brown, with darker areas on the dorsum, inguinal, axillary and tympanic zones and on limbs. In some specimens (e.g., MTSN 8129), darker areas on the dorsum are extensive and almost black. The entire animal has a metallic sheen that persists after preservation. Eye colour in life is bright yellow to orange.

Call. Advertisement calls of two males Callulina meteora were recorded at the collecting site by M.M. between October 26 and November 2 2004 both during the day and the night. Calling males were seen at the base of trees. The call is composed of a single periodic pulse train, introductory notes, and repeated notes. These three elements are sometimes arranged in different ways: a single periodic pulse train could be heard with or without introductory notes. Full calls in rainy weather were heard to comprise three or four modules of introductory notes followed by a single pulse train and a final introductory note followed by a group of similar pulse trains. The presence of the introductory note was previously known for the recently described C. kanga only ( Loader et al., 2010b). The last call element of C. meteora considered alone shows temporal properties similar to the call of the other Callulina species. The single periodic pulse train is composed of six pulses and has a length ranging from 0.067 to 0.078 sec, but the temporal properties of repeated note remains the same. The introductory notes usually rising in intensity are composed of 16 to 21 pulses and have a length ranging from 0.203 to 0.238 sec. All sound emissions have an average intensity maximum around 1.6 kHz (see Fig. 3 View FIGURE 3 ).

Habitat and natural history. Callulina meteora is partly sympatric with C. hanseni ( Loader et al., 2010b) and seems to be restricted to the montane and upper montane forest of the Nguru South Forest Reserve (Menegon et al., 2008). All specimens were collected between 1950–2100 m asl but calls were heard up to 2200 m. This distribution is similar to that reported for Arthroleptis nguruensis ( Poynton et al., 2009) . Some specimens were found during the day by digging in soft soil and leaf litter accumulating at the base of large trees. This microhabitat together with the presence of strongly keratinized and well-raised metatarsal tubercles is suggestive of semifossoriality. On the basis of the presence of large eggs found in the oviduct of a dissected female, we presume that the species is oviparous with direct development. Although no direct evidence is known for the genus Callulina , oviparity with direct development is regarded as the most likely reproductive mode for this genus of breviciptids ( Müller et al., 2007).

Conservation status. Based on current knowledge of the species’ distribution and habitat preference, the estimated extent of occurrence of Callulina meteora is equal to or less than 42 km 2, and the estimated area of occupancy not larger than 26 km 2; these are respectively the area including the elevational distribution (1980–2100 m) of this species in the Nguru South Forest Reserve and the area included in the polygon obtained by linking the localities where the presence of the species was recorded ( Fig. 6 View FIGURE 6 ). Therefore, according to Red List (IUCN 2009) categories based on the criterion of an extent of occurrence estimated to be less than 100 km 2, the presence of one population at only a single location, compounded with an observed decline in area, extent and quality of the habitat (IUCN, 2010), we suggest that C. meteora qualifies as critically endangered or, more technically, CR B1b (iii). The proposed conservation status would need to be re-evaluated if specimens are recovered below 1980 m, but herpetological surveys examining species turnover between 800–2200 m have been conducted in the area over the past seven years (S.P.L. and M.M. unpublished data; Owen et al., 2008) and C. meteora has never been recovered below 1980 m. Currently the population density appears to be locally high but with increasing pressure due to land-use changes in the region (pers. obs.), and predicted climate-mediated changes that could affect the high montane zone, the species is clearly facing threats.

Etymology. The specific epithet is used as an adjective and derives from the greek word meteoron, meaning "thing high up," in reference to the type locality of the species, situated close to the top of the Nguru Mountains.

Molecular analyses. To examine the distinctiveness of and relationships among Callulina species, we analysed sequence data for 12S, 16S, and cytb mt genes for all nine nominal species, including C. meteora . The dataset comprised 24 individuals and 1124 unambiguously aligned characters, of which 707 were constant, 140 variable and uninformative, and 277 informative under parsimony. Breviceps mossambicus was used to root trees and Probreviceps m. macrodactylus and Spelaeophryne methneri were used as additional outgroups (see Loader et al. 2010a).

Parsimony analysis yielded two most parsimonious (MP) trees of 915 steps ( Fig. 5 View FIGURE 5 b). These topologies differ from the optimal likelihood tree ( Fig. 5 View FIGURE 5 a). The two MP trees differ in the position of C. shengena and C. kanga . In one MP tree, C. shengena is sister to C. laphami , and in the other it is sister to all other (except C. laphami ) Callulina species. Callulina kanga is recovered as sister to a clade comprising a Nguru radiation ( C. meteora , C. hanseni ), C. dawida , C. stanleyi and C. kisiwamsitu in the former MP tree. In the second, C. kanga is sister to C. kreffti . Neither of the alternative topologies is well supported. Most analyses supported the monophyly of Callulina (best trees with a non-monophyletic Callulina are significantly suboptimal in Templeton but not likelihood topology tests). All nominal species are robustly monophyletic ( Fig. 5 View FIGURE 5 ). Likelihood analysis recovered a tree similar to that presented by Loader et al. (2010a: fig. 8b) differing only in the position of C. shengena . In Loader et al. (2010a) C. shengena was sister to all other Callulina species (but not well supported) whereas here C. shengena is sister to C. laphami , also only very weakly supported. The new species, C. meteora , forms a clade with C. hanseni in all analyses. Pairwise distances values highlight the genetic distinctiveness of all named Callulina species (as previously shown in Loader et al., 2010b), including the new species C. meteora (3.8–4.0 % different to its sister group C. hanseni ). Despite the genetic distinctiveness of the nominal species, the phylogenetic signal in the available mt sequence data is insufficient to provide a compelling resolution of their interrelationships using the methods employed here.