Ambangulu Puddle Frog
|Species Description: Greenwood L, SP Loader, L Lawson, E Greenbaum, and BM Zimkus. 2020. A new species of Phrynobatrachus (Amphibia: Anura: Phrynobatrachidae) from the Northern Mountains of Tanzania. Journal of Natural History. https://doi.org/10.1080/00222933.2020.1757171|
Phrynobatrachus ambanguluensis is a pointy-headed frog with a male snout-vent length range of 20.0 - 45.3 mm and a female range of 21.1 - 39.6 mm. The characteristics of its head and associated features are as follows: head pointed with a tapered snout. The canthus rostralis is obliquely directed and flat. The snout distinctly overhangs the lower jaw. The nostrils are at the end of the blunt snout, near the edge of the canthus rostralis, and positioned closer to the apex of the snout (1/3 of the total distance of the eye to the snout end) than the eye. The tongue present with medial conical papilla. The choanae is visible and is anterior to the roof of the mouth. The eyes represent about 1.5x the size of the tympanum, the latter being distinct and circular. The interorbital distance is twice as large as the upper-eyelid distance. Unpaired vocal sacs are positioned in subgular region, but not easy to decipher. Other noticeable characteristics comprise the absence of glandular mass under the armpits. The palm shows both an inner and outer metatarsal tubercule with the former being long and thin and is directed along the inner edge of the thick nuptial pad on the thumb while the latter is rounded and relatively large. The fingers moderately long and do not show any webbing with distal and slightly expanded toe tips. The first finger is shorter than both the second and third while the second is longer than the third. The tibio-tarsal articulation reaches the snout with the knee joint adjacent to the anterior margin of the tympanum. The legs are long with muscular thighs. The tarsal tubercle clearly visible and the toes are relatively long and thin, with extensive webbing (1e(0), 2i(1), 2e(0), 3i(0.5), 3e(0), 4i(1.5), 4e(0), 5i(0)). The tips of toes slightly swollen and expanded. Tubercles are present on the inner toe, long and thin, directed along the inner edge of the first toe. A small-rounded tubercle is present on the outer/mid-portion of the anterior margin of the foot and spines can be found on the toes between the tubercles (Greenwood et al. 2020).
There are number of features that distinguish P. ambanguluensis from its sister species P. krefftii and perhaps the most notable of all is the shape of the snout, in the latter, the upper and lower jaw more or less extends to the same point in lateral view, whereas in the former the snout visibly extends beyond the lower jaw in both ventral and lateral view. Similarly, the snout is rounded in dorsal view in the latter, whereas the former’s is more pointed arrow-like shape. Similarly, the color of P. ambanguluensis is much darker, as opposed to that of P. krefftii, which is typically lighter with more distinct patterning. In addition, the cartilage cushion differs between the two sister species, with a lighter brown than the tympanic membrane in P. ambanguluensis and darker in P. krefftii (Greenwood et al. 2020).
In life, brown colouration is dominant in P. ambanguluensis though it slightly darkens or lightens here and there. The species dorsal view shows a brown mottling, with a darker thin brown interorbital band that is light brown edged on the anterior side at the mid-line of the eyes. The snout is light brown as well. So are the legs, except that they show a slightly darker brown banding on their length. Small white spines are found regularly distributed along with all toes between tubercles. The ventral view shows that the lower jaw is edged with brown overlaying a cream-yellow colouration. The gular flap is lighter brown coloured, with a darker cream/brown ventral region, mottled with light brown along edges of the legs. In preservation, the yellow colorations fade, but otherwise coloration is similar to that in life (Greenwood et al. 2020).
Phrynobatrachus ambanguluensis is sexually dimorphic both in size and aspects of throat coloration. Mature males exhibit a bright yellow throat with an unpaired subgular vocal sac whereas females lack the vocal sac and their throat is brown and slightly speckled. Males are also larger with a maximum snout-vent length of 45 mm versus 40 mm in females (Greenwood et al. 2020).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Tanzania, United Republic of
Life History, Abundance, Activity, and Special Behaviors
Male P. ambanguluensis have been observed calling either sitting in shallow water or on the edge. Calls are described as a soft trill of 7 – 11 pulsed notes (mean 9.4), emitted at a rate ranging between 17.2 – 19.6 s -1 (mean 18.0), with a dominant frequency that varies from 2153 – 2928 Hz (mean 2820) (Channing 2020).
Visual signaling in which males do not call but instead flash their yellow vocal sac has been observed in this species. Similar non-vocal communication has also been documented in its sister species P. krefftii in which flashing throat has a role in male-male confrontations (Channing 2020).
In preservative the colouration is not uniform. In dorsal view, the pigmentation is dark brown, solid over body, but absent below the eyes and nostrils. Pigment is present medial to nostrils. The tail muscle and dorsal fin speckled while the ventral fin is clear. The ventral surfaces are unpigmented with the gut visible through transparent body wall (Channing 2020).
Trends and Threats
Maximum Likelihood and Bayesian analyses on 16S rRNA found that P. ambanguluensis is sister to P. krefftii, which it was previously mistaken to be (Greenwood et al. 2020).
Phrynobatrachus ambanguluensis was assigned to the genus Phrynobatrachus because it shares many of the features common to members of this taxonomic group. Notably, the absence of webbing between fingers, presence of elongated mid-tarsal tubercules and elongated inner and small round outer metatarsal tubercules (Greenwood et al. 2020).
Channing, A. (2020). The advertisement call and tadpole of the Ambangulu Puddle Frog (Phrynobatrachus ambanguluensis) (Anura: Phrynobatrachidae) from Tanzania. Journal of Natural History, 54, 2889 – 2896. [link]
Originally submitted by: Marcel Kouete (2023-06-21)
Description by: Marcel Kouete (updated 2023-06-21)
Distribution by: Marcel Kouete (updated 2023-06-21)
Life history by: Marcel Kouete (updated 2023-06-21)
Larva by: Marcel Kouete (updated 2023-06-21)
Trends and threats by: Ann T. Chang (updated 2023-06-21)
Comments by: Marcel Kouete (updated 2023-06-21)
Edited by: Ann T. Chang (2023-06-21)
Species Account Citation: AmphibiaWeb 2023 Phrynobatrachus ambanguluensis: Ambangulu Puddle Frog <https://amphibiaweb.org/species/9200> University of California, Berkeley, CA, USA. Accessed Sep 24, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Sep 2023.
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