Description
Xenorhina salawati is a medium-sized frog with a snout-urostyle length of 29.9 – 34.3 mm in males and 29.1 – 35.2 mm in females. The snout protrudes and tapers to a point. The nostrils are near the tip, directed laterally, and visible from above but not below. There are several small depressions on the tip of the snout, and there is no visible canthus rostralis. The loreal region is oblique. The distance from the eye to naris is greater than internarial distance. The tympanum is clearly visible with a diameter only slightly less than the eye (tympanic diameter to eye diameter ratio = 0.86). The tympanic region of the head is broad, with a weakly expressed supratympanic fold from the posterior eye to the insertion of the forelimb and a weak constriction at the neck. There are distinct tubercles visible on the lateral body both in life and preserved specimens. The dorsal extremities, middle of the dorsum, and the ventral surfaces appear smooth. The fingers are unwebbed and short with comparative finger lengths of 3 > 4 = 2 = 1. Despite the fingers lacking expanded discs, there are circum-marginal grooves present on the tips of fingers 2 and 3 and traces of grooves on fingers 1 and 4. In contrast to fingers, all toes have circum-marginal grooves along their tips, and toes 2 - 5 end in wide discs that are larger than the penultimate phalanges. The toes are also unwebbed, with comparative lengths of 4 > 3 > 5 > 2 > 1. Tubercles are present on the metatarsal region, but no tubercles are present on subarticular, palmar, or plantar surfaces (Günther et al. 2020).

DIAGNOSIS:

Xenorhina salawati is among a group of Xenorhina species that lack vomero-palantine spikes and was compared to the other species in this group by the species authority. This group includes X. adisca, X. arboricola, X. arndti, X. bouwensi, X. brachyrhyncha, X. eiponis, X. macrodisca, X. minima, X. oxycephala, X. parkerorum, X. similis, and X. varia, and finally X. waigeo, which was described in the same article as X. salawati and is the most morphologically similar. However, X. salawati is larger than X. adisca, with longer legs, and has expanded discs on toes. It is, however, smaller than X. arboricola, and does not share the strongly expanded finger discs present in X. arboricola (Gunther et al. 2020). Notably, X. oxycephala is likely to be polyphyletic given mDNA studies (Gunther 2010, Gunther et al. 2020), but is larger than X. salawati and has broadened discs on its fingers, which are not present in X. salawati, as well as smaller eyes. Xenorhina macrodisca and X. varia also have strongly expanded finger discs, which are lacking in X. salawati. Xenorhina minima lacks expanded discs on toes, which are present in X. salawati, and has shorter legs. Compared to X. arndti, X. salawati is larger and has wider finger and toe tips, as well as a longer internarial distance. Xenorhina bouwensit and X. brachyrhyncha are also smaller than X. salawati. Xenorhina eiponis has longer legs than X. salawati. Xenorhina parkerorum and X. similis are both significantly larger than X. salawati, and X. similis has shorter legs. Lastly, X. waigeo is most like X. salawati, and differs primarily in advertisement call series, with X. salawati’s series being greatly elongated and consisting of 2 - 4 times more calls per series compared to X. waigeo’s. Slight morphological differences between the two species include X. salawati having mildly shorter legs and 4th toes, as well as a greater distance between the eye and snout tip compared to X. waigeo. In preservative, X. salawati have lighter dorsal surfaces, strong mottling of the throat, and less intensely pigmented surfaces of fingers and toes compared to X. waigeo (Günther et al. 2020).

COLORATION:

In life, the dorsal head, body, and extremities are a uniform light reddish-brown with two semi-circular light yellow lumbar spots. The lower flanks have off white and dark brown patches, as well as dark brown patches below the eye, along supratympanic ridge, around vent, and on anterior and posterior extremities. The tubercles of the lateral surfaces of the body and dorsal surfaces of the extremities appear white-on-brown. Uniform light yellow coloration is present on throat, belly, and partly ventral surfaces of extremities. The throat is covered in grey-brown network. Two zinc-yellow longitudinal stripes on the abdomen form a pear shape. The tip of the snout is grey with several darker grey indentations. The ventral surface of the hand and foot are predominantly shades of grey. The anal region, proximal posterior of the thigh, and entire posterior tarsi are dark brownish grey. The iris is black with a golden inner margin (Günther et al. 2020).

In preservative, the dorsal surface color changed from reddish brown to beige, ventral surfaces changed to creamy white. Dark skin regions remain the same color as they are in life. The lumbar spots are less pronounced (Günther et al. 2020).

VARIATION:

There are no notable differences in body size or ratios noted between the sexes. As noted above, in life the ventral surfaces are melon-yellow or dark brown with white spots and dorsal surfaces are tones of reddish brown or blueish. In preserved specimens, ventral surfaces vary from ivory-white without spots to brownish with ivory-white spots, and dorsal surfaces vary from beige to brown. The throat is also ivory-white with varying degrees of brown speckling. A mid-dorsal stripe of varying prominence may extend onto the hind limbs, and lumbar spots are less pronounced in preserved specimens than live ones. There is also a grey snout tip present on most specimens that becomes more pronounced when preserved (Günther et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Indonesia

View distribution map in BerkeleyMapper.

At the time of the species description, X. salawati was only known from a single, lowland rainforest location near the northern coast of Salawati Island in Indonesian New Guinea, found at 50 m above sea (Günther et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
Xenorhina salawati is semi-fossorial species. Calling males were found at night within the humus layer, beneath leaf litter in lowland rainforest while females and non-calling males were found on the forest floor at night (Günther et al. 2020).

Four calls were recorded and analyzed from the holotype at 25^oC with an average call series length of 8.08 s and an average of 15.2 calls per series. Call duration was averaged at 72 ms, with a range of 52 - 87ms, and an average duration of intervals between calls measured at 478 ms. Calls were unpulsed, approximately equal length and at equal intervals, with a noted rise in volume and pitch during the first half of each series of calls, occasionally extending over the entire call series, although they often decrease slowly, after peaking near the halfway point, until the end of the call. All calls are noted to have harmonic structures between 6 - 8 harmonics between 0.20 and 3.90 kHz, with a clearly dominant first harmonic with a peak of 0.5 kHz (Günther et al. 2020).

Trends and Threats
No threats were documented when the species was described (Günther et al. 2020). However, given the species’ limited known area of distribution, threats are likely to include destruction of habitat, decreased genetic variance due to small population size, and vulnerability to disease. More research is necessary to better understand the threats to this species’ continued existence.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities

Comments
Xenorhina salawati was described based on morphology alone (Gunther et al. 2020). Xenorhina includes species with one or more spikes on the vomero-palatine bone, which were previously referred to as Xenobratrachus, as well as another group lacking these spikes. Xenorhina salawati lacks these spikes, falling within the same category as X. adisca, X. arboricola, X. arndti, X. bouwensi, X. brachyrhyncha, X. eiponis, X. macrodisca, X. varia, X. minima, X. oxycephala, X. parkerorum, and X. similis, and finally X. waigeo, which was described in the same article and is likely most closely related to due to similarities in morphology (Gunther 2010, Gunther et al. 2020). However, more research is required into this area as a whole.

OTHER INTERESTING INFORMATION:

As of its first description in 2020, X. salawati is one of only three members of its genus endemic to the Raja Ampat Islands, the other two being X. varia, and X. waigeo (Günther et al. 2020).

References
Günther, R. (2010). Description of a new microhylid frog species of the genus Xenorhina (Amphibia: Anura: Microhylidae) from the Fakfak Mountains, far western New Guinea. Vertebrate Zoology, 60(3), 217-224. [link]

Günther, R., Richards, S., Tjaturadi, B., and Krey, K. (2020). Two new microhylid frog species of the genus Xenorhina Peters, 1863 from the Raja Ampat Islands, Indonesia. Vertebrate Zoology, 70(3), 333-347. [link]

Species Account Citation: AmphibiaWeb 2024 Xenorhina salawati <https://amphibiaweb.org/species/9248> University of California, Berkeley, CA, USA. Accessed May 12, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 May 2025.

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