AMPHIBIAWEB
Callulina stanleyi
family: Brevicipitidae
 
Species Description: Loader SP, Gower DJ, Ngalason W, Menegon M 2010 Three new species of Callulina (Amphibia: Anura: Brevicipitidae) highlight local endemism and conservation plight of Africa's Eastern Arc forests. Zool J Linn Soc 160: 496-514.

© 2010 Michele Menegon (1 of 1)
Conservation Status (definitions)
IUCN (Red List) Status
CITES
Other International Status None
National Status None
Regional Status None

Country distribution from AmphibiaWeb's database: Tanzania, United Republic of

 

View distribution map using BerkeleyMapper.

   

From the Encyclopedia of Life account:

Etymology

This species is named after William T. Stanley of the Field Museum, Chicago. Bill has made numerous contributions to understanding the biological diversity of the Eastern Arc Mountains. He has also made several important field discoveries of amphibians (including those we describe from the South Pare). Loader et al. (2010) named this species in recognition of his excellent work.


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Summary

A medium to large sized robust Callulina. Snout-urostyle distance reaching 42.5 mm, Snout-tibia ratio 0.33-0.39. Tympanum present but sometimes obscured by granular skin. Finger tips usually expanded, with the ratio between the width at first subarticular against width at distal phalanx 0.8-1.0. Subarticular tubercles of hands and feet prominent.


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Distribution

Callulina stanleyi was found only in submontane forest at elevations between 1200 m and 1300 m. Based on current knowledge of the species’ distribution and evidence of dependency on forest, the estimated extent of occurrence of C. stanleyi is equal to or less than 9.7 km2; this is the area including an elevational distribution (1200 – 1600 m) of the submontane habitat in Chome. As with the two other newly described species, population density does not appear to be low, but C. stanleyi is confined to a small fragment of submontane forest existing along the eastern boundary of Chome forest reserve, which is bordered by extensive farmlands. The presence of one population at only a single, small location, is compounded by an observed decline in area and quality of the habitat (Hall et al., 2009).


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Osteology

de Sá et al., (2004) and Loader et al., (2009) provided assessments of the internal morphology of the new Callulina species they described. These two studies utilised characters previously identified in Parker’s (1934) review of the morphological diversity in microhylids (brevicipitids were previously classified in Microhylidae). Largen & Drewes (1989) provided additional data in their description of the new brevicipitid genus Balebreviceps. Largen & Drewes (1989) and Parker’s (1934) studies provided important characters for differentiating primarily among breviciptid genera, less so among species (de Sa et al., 2004; Loader et al., 2009). For this study we investigated the skeletal morphology of all the new species, and provide brief summaries.

Characters common to all Callulina species: (1) Palate with denticulate ridge in front of pharynx, and anteriorly two weakly defined, broad arcuate smooth ridges. (2) Parasphenoid cultriform process broad based but narrower, almost wing-like structure tapering medially, the anterior end tapering only slightly. (3) Mentomeckelian – posteroventral processes smaller than those of Probreviceps; wedge-shaped as in Balebreviceps but with a more acute angle. (4) Procoracoids and clavicles present, well developed, straight, slightly curved distally at the joint between coracoid and scapulae. (5) Large omosternum. (6) double condylar articulation between the urostyle and the sacral vertebra. (7) Diplasiocoelous vertebrae.

Characters varying among Callulina species: Bony part of finger and toe tips expanded clearly beyond the width of the base of the terminal phalanx in C. kreffti, expanded marginally in C. stanleyi and C. kisiwamsitu, about same width of the base of the phalanx in C. dawida, C. laphami, and C. shengena.


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

Body robust. Tips of fingers expanded, distal width of terminal phalanx 0.85 of the width of distal subarticular tubercle. Tips of fingers expanded laterally, with circummarginal grooves posterior to distal phalanx. First finger shortest, second and fourth equal, third longest. Inner metatarsal tubercle rounded and raised, separated by a middle palmar tubercle from an even larger, rounded, raised, outer metatarsal tubercle. Slightly smaller palmar tubercles present on palm. Subarticular tubercles at the base of each finger, large subarticular tubercles on third and fourth finger at the phalangeal joints. Third finger with smaller tubercles between basal articular tubercle and subarticular tubercles. Slightly dessicated but dorso-ventrally expanded toe tips with slightly folded but smooth ventral surface. Tips of toes slightly expanded laterally, with circummarginal grooves posterior to distal phalanx. Toe tips with smooth ventral surface. First toe same length as second, third and fifth equal, fourth longest. Inner metatarsal tubercle large, rounded and raised, almost touching a similar sized, rounded, raised, outer metatarsal tubercle. Smaller palmar tubercles present on base of foot. Subarticular tubercles at the base of each toe, large subarticular tubercles on third and fourth toe at the phalangeal joints. All tubercles on hands and feet bluish/grey against brown/grey background. Dorsum brown with scattered, darker brown/black symmetric vermiculations. Skin granular, with slightly larger glandular masses on lateral sides and posterior end around the thighs and urostyle region. Large glandular mass slightly paler brown. Ventral surface paler brown, cream-tan. Tympanic region pale brown/cream. Dark edged tympanic ridge from posterior edge of eyelid to arm insertion. Incision around tympanic region on right side. Loreal and canthal regions dark brown. Snout visible from ventral view (Loader et al., 2010).


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Comparisons

C. stanleyi differs from Callulina kreffti in having less expanded third finger (>0.75 distal width at third terminal phalanx - distal width at subarticular tubercle). C. stanleyi differs from Callulina dawida in having expanded finger and toe tips. C. stanleyi differs from Callulina laphami and C. shengena by presence of a tympanum, and expanded toe and finger tips. C. stanleyi is morphologically very similar to Callulina kisiwamsitu, though the two species can be distinguished on the basis of DNA sequence, call, and distribution data. Additionally, the following morphometric characters (against SUL) differ significantly (p < 0.05) in the two species based on T-test analyses: TD, ED, ND, JW, NLD, IOD, snout length (as measured from lower lip to apex of anterior dorsal margin of snout), outer metatarsal tubercle of the hand (as measured along its longest axis). Many of the head character differences between C. stanleyi and C. kisiwamsitu and indicate the larger, more robust head of the former.


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Habitat and Ecology

The holotype was collected in a rotten log in forest. Other specimens were all collected in bucket pitfalls in the forest. Specimens were found on low bushes during the night both in dense forest and along a forest road (Loader et al., 2010).


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/

Phylogenetics

To test the distinctiveness of Callulina species and infer their evolutionary relationships we constructed two alignments of sequence data for all six described species: (1) all Callulina individuals for which 12S and 16S were available (2) all individuals for which 12S, 16S and cytb were available. The two datasets comprised (1) 18 individuals with 762 unambiguously aligned characters, of which 533 were constant, 89 variable, and 140 informative under parsimony (only 1 gap present, alternative coding of this gap made no difference in resulting trees), and (2) 14 individuals with 1185 unambiguously aligned characters, of which 884 were constant, 98 variable, and 203 informative under parsimony. Phrynomantis was used as outgroup as in previous analyses, following Loader et al., (2009). Analysis of Alignments 1 and 2 yielded single most parsimonious (MP) trees of 422 and 870 steps, respectively, and the trees (not shown) are not notably different to those recovered in likelihood and Bayesian analyses. Maximum likelihood (ML) and Bayesian analyses were conducted with the GTR+I+G model. Both analyses supported the monophyly of Callulina, and rejected suboptimal topologies in most tests. For Alignment 1 both analyses demonstrate the genetic distinctiveness of the named species, with highly supported reciprocally monophyletic groupings recovered for each, and suboptimal topologies significantly different in MP tests (apart from C. stanleyi - see Figure 8a). The truncate finger/toe species (C. dawida, C. laphami, C. shengena) form a paraphyletic assemblage outside a clade of all expanded finger/toe species. The sister species grouping between C. shengena and C. laphami is weakly supported. The expanded finger/toe clade of C. kreffti, C. kisiwamsitu, and C. stanleyi is weakly supported, though the sister pair of the morphologically similar C. kisiwamsitu and C. stanleyi is strongly supported. Both analyses of Alignment 2 recover multiple individuals of each named species (where included) together in maximally supported clades and significantly different from suboptimal topologies. Different from Alignment 1, C. shengena is recovered as the sister to all other species instead of grouping with C. laphami, though this is weakly supported. Analyses of Alignment 2 (as with Alignment 1) recovered a truncate toed paraphyletic assemblage outside a clade of all expanded finger/toe species. Constrained topologies including a monophyletic North and South Pare radiation (C. stanleyi, C. lapami, C. shengena), or a monophyletic South Pare (C. stanleyi, C. shengena) radiation are both statistically significantly suboptimal for both alignments using MP and ML (p= <0.05). Pairwise distances show high values highlighting the genetic distinctiveness of all named Callulina species (>4.2%, mean of 8.4% among all species).


Author: Loader, Simon
License: http://creativecommons.org/licenses/by-nc/3.0/