Description
Diagnosis: The following combination of characters distinguish this species from congeners: small body size, dark brown dorsum with small darker spotting, loreal and lateral regions with bluish-white spotting, femoral patches of pale orange-red, slightly tuberculate dorsum and upper limbs, speckled and somewhat granular venter, toes with basal webbing, outer metatarsal tubercle usually spatulate and oriented perpendicular to foot, maxillary teeth present, frontoparietal fontanelle broadly exposed, presence of moderately developed parotoid and inguinal glands and less developed coccygeal glands, and a high-pitched rasping advertisement call (Doughty and Roberts 2008).

Description: Adult males measure 18.0-21.5 mm SVL. One adult female measured 20.5 mm SVL. Small rotund body with short limbs. Small head with an oval tongue. Eyes protrude slightly and the anterior corner of the eye is covered by a flap of skin. Pupil is rhomboidal in shape. Lacks vomerine teeth, but has maxillary teeth. Rounded canthus rostralis and moderately steep, slightly concave loreal region. Infralabial glands (one to three) present beneath jaw angle. The tympanum is covered by the skin and parotoid glands. Unwebbed fingers with moderately developed tubercles (one each on Fingers I and II; two each on Fingers III and IV). Finger I shorter than Finger II. Short legs. Toes are basally webbed, have weakly developed flanges along their length, and moderately developed tubercles underneath (one on Toes I, II; two on Toes III and V; three on Toe IV). Inner metatarsal tubercle weakly developed. Outer metatarsal tubercle generally spatulate in shape (sometimes round) and protruding perpendicularly from the foot. Usually has parotoid, dorsolateral, and coccygeal glands. Cloacal flap is present. Scattered low tubercles on the skin of the dorsum, head and limbs. Ventral surfaces are moderately granular. Males have a nuptial pad on the inner part of Finger I, from halfway down the finger to the base of the wrist and barely onto the palm (Doughty and Roberts 2008).

In life, specimens from the mainland had a slightly different coloration than those from Katers Island. In mainland specimens, the dorsum ranged from a charcoal black to dark brown with random smaller dark blotches and faint bars on the limbs. Slight orange-red tint on dorsum, and orange-red blotches on the parotoid glands, snout tip, submandibular glands, vertebral area, and upper arms. Pale bluish-white specks are found on the tip of the snout, through the loreal region, along the sides and on the undersurfaces of the limbs. Pale white ventral surfaces speckled with dark spots, except for abdomen which is uniformly pale (neither white nor speckled). Chin margin is slightly more pigmented. Iris is chestnut brown with a green tint. Creamy white fingers and toes (Doughty and Roberts 2008).

Specimens from Katers Island had slightly lighter coloration and orange-red inguinal glands (Doughty and Roberts 2008).

In preservative, the body is almost completely black with a tint of orange and red visible in some areas (Doughty and Roberts 2008).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Australia

View distribution map in BerkeleyMapper.

Endemic to Australia. Only found in high rainfall areas (over 1000 mm/year) such as the northwest Kimberley, Western Australia, the Prince Regent River Nature Reserve south to Walcott Inlet, Western Australia and on Katers Island, Western Australia. The type locality is near Bachsten Creek, in the southwest portion of the Prince Regent River Nature Reserve. Habitat consists of generally moist areas such as creeks and rocks near water (Doughty and Roberts 2008).

Life History, Abundance, Activity, and Special Behaviors
Males called from moist crevices in sandstone rocks on a high ridge or from crevices and cracks in rock faces with vegetation and seepages. Others were found calling on hard-capped sandstone surfaces with small pools of slow flowing water among clumps of Triodia vegetation. Long high-pitched call with a dominant frequency of 3347 Hz; there is some modulation as frequency rises later in the call. Reproduction is aquatic. Eggs are small and pigmented, hatching into free-swimming larvae (Doughty and Roberts 2008).

Comments
The specific epithet is derived from the Greek word mikros which alludes to the species' small size (Doughty and Roberts 2008).

References

Doughty, P. and Roberts, J. D. (2008). ''A new species of Uperoleia (Anura: Myobatrachidae) from the northwest Kimberley, Western Australia.'' Zootaxa, 1939, 10-18.

Species Account Citation: AmphibiaWeb 2010 Uperoleia micra <https://amphibiaweb.org/species/7216> University of California, Berkeley, CA, USA. Accessed Sep 12, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Sep 2024.

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