Description
Boophis lilianae is a small treefrog with the male holotype measuring 18.3 mm SVL and the female paratype 20.0 mm SVL. The head is wide as long and wider than the slender body. Snout is mucronate in dorsal view for the male holotype, truncate in dorsal view for the female paratype, and obtuse in lateral view. Nostrils are directed laterally, distinctly protruding, and closer to tip of snout than to eye. Canthus rostralis is rounded; loreal region slightly concave; tympanum distinct; and supratympanic fold weak. The tongue is narrowly cordiform, posteriorly distinctly bifurcated and half free. Vomerine odontophores are absent. Arms are generally slender with fingers having small weakly developed subarticular tubercles, and lacking distinct metacarpal tubercles. Fingers show basal webbing as well as lateral dermal fringes. Relative length of fingers increases from 1,2,4,3; finger discs are moderately enlarged; and medium-sized nuptial pad on inner side of first finger lacks pigment. Hindlimbs also appear slender with tibiotarsal articulation that reaches the snout tip when hindlimb is adpressed along body. Inner metatarsal tubercle is distinct and elongated, but outer metatarsal tubercle is absent. Webbing between toes is well-developed and lateral dermal fringes are present. Relative toe length increases from 1,2,5,3,4 and toe discs are moderately enlarged. Dorsally the skin is smooth with widely scattered tubercles. Throat and chest are smooth. The belly appears coarsely granular and the skin around the cloacal opening is glandular but lacks enlarged tubercles (Kohler et al. 2008).

In preservative, Boophis lilianae exhibits creamy yellow coloration on dorsal and ventral surfaces. A pink canthal stripe runs from snout tip to upper eyelid, and a thin brown line encircles the nostril. Upper eyelid is covered by brown blotches, bordered by pink spots. Two fine longitudinal parallel stripes appear on mid-dorsum that are formed by rows of pink spots. There is also a small pink fleck on the knee (Kohler et al. 2008).

In life this species shows translucent yellowish green coloration on the dorsum that appears transparent in the groin. A reddish canthal stripe runs from snout tip to upper eyelid. The thin reddish supratympanic line fades at level of urostyle. Upper eyelid is covered by reddish brown blotch, and between the eyes there is a weak brownish triangular fleck. Two fine longitudinal stripes appear on mid-dorsum that extendsfrom behind scapular region to urostyle. Between the stripes there are some irregular pink marbling spots. Reddish brown spots also appear on heel and knee. Dorsal surfaces of fingers, toes, and terminal discs look yellowish green. Ventral surfaces of limbs, chest and throat are colored a green shade of turquoise. Belly is white and bones are green. The inner iris looks silvery grey, with a fine brownish circular line. Outer iris is golden yellow, with a black triangular fleck above and below pupil. Posterior iris has black on the periphery, adjoined by light blue (Kohler et al. 2008).

A diagnosis of Boophis lilianae with other species of the genus Boophis shows that this treefrog is so far the smallest known species in the genus. It is distinguished from members of the B. rappiodes and B. mandraka species groups by a pigmented ventral side and from members of the B. albipunctatus and B. luteus species groups by lack of lateral dermal fringes along lower arm and tarsus. Moreover, it differs from B. baetkei in smaller adult male size (18.3mm SVL in B. lilianae vs. 30.8mm for B. baetkei) and mucronate male snout shape (vs. rounded in B. baetkei) and a relatively smaller tympanum, as well as lacking vomerine odontophores (Kohler et al. 2008; Wollenberg et al. 2008).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Madagascar

View distribution map in BerkeleyMapper.

Boophis lilianae is known definitively only from a single amplexing pair at one locality in Fianarantsoa Province, Madagascar, at 468m asl, although another possible pair was sighted at Imaloka, within Ranomafama NP, at 900-1000m asl. The extent and occurrence of Boophis lilianae remains unknown. Although assumed to dwell exclusively in rainforest, this species is secretive and may have passed unnoticed at other surveyed rainforest sites in eastern Madagascar (Kohler et al. 2008; Andreone et al. 2000).

Life History, Abundance, Activity, and Special Behaviors
The two type specimens were collected at night, in amplexus, while sitting on low vegetation in a swampy area adjoining a slow-flowing stream. The female had yellowish eggs (each approximately 1.6mm in diameter) in the oviducts, which were visible through the transparent flanks. This indicates that reproduction was taking place at the time of collecting (during the rainy season) and that Boophis lilianae may be a seasonally reproducing frog (Kohler et al. 2008). Calls have not yet been recorded, and since only single amplexing pairs have been found, this species may either be very seasonal or very secretive in calling behavior (Kohler et al. 2008; Wollenberg et al. 2008). Tadpoles have been collected but not yet described (Kohler et al. 2008). This species occurs in sympatry with B. madagascariensis, B. opisthodon, and B. pyrrhus.

Trends and Threats
This species qualifies as "Data Deficient" since its extent of occurrence and area of occupancy are not known (Kohler et al. 2008). The type locality occurs in an unprotected area, while another possible locality lies within Ranomafama National Park.

Comments
This species is dedicated to Liliane Raharivololoniaina who collected specimens of Boophis lilianae and B. baetkei, in recognition of her contribution to the study of Madagascan amphibians (Kohler et al. 2008).

References

Andreone, F., Randrianirina, J.E., Jenkins, P.D., and Aprea, G. (2000). ''Species diversity of Amphibia, Reptilia and Lipotyphla (Mammalia) at Amolokopatrika, a rainforest between the Anjanaharibe-Sud and Mrojejy Massifs, NE Madagascar.'' Biodiversity and Conservation, 9, 1587-1622.

Kohler, J., Glaw, F., and Vences, M. (2008). ''Two additional treefrogs of the Boophis ulftunni species group (Anura: Mantellidae) discovered in rainforests of northern and south-eastern Madagascar.'' Zootaxa, 1814, 37-48.

Wollenberg, K. C., Andreone, F., Glaw, F., and Vences, M. (2008). ''Pretty in pink: A new treefrog species of the genus Boophis from north-eastern Madagascar.'' Zootaxa, 1684, 58-68.

Species Account Citation: AmphibiaWeb 2008 Boophis lilianae <https://amphibiaweb.org/species/7147> University of California, Berkeley, CA, USA. Accessed Sep 18, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 18 Sep 2024.

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