Source: Tayloofactsone
Description
Paedophryne amauensis is a very small frog, one of the smallest terrestrial vertebrates in the world with a male snout 7.0 – 8.0 mm long. The range of female vents is currently undetermined as only males have been found. Head is wider than long. It has a wide and short snout. Its eyes are relatively large. The fingers are not sticky and end up with slightly extended discs. The first, second and fourth fingers are greatly reduced, especially the first, which is the vestibule. The phalangeal formula for the hand is 1 – 2 – 3 – 2. Frogs have moderately long legs with a tibial to snout length ratio ranging from 0.478 – 0.507. It has no net pins and a bit big disk. The first toe was reduced to the vestibular knob and the second and fifth toes were also significantly reduced. The number of phalanges in the legs is 1 – 2 – 3 – 4 – 2. This species has only seven anterior vertebrae (Rittmeyer et al. 2012).
From species other than the genus, P. amanuensis can be distinguished by having fewer presacral vertebrates (7 instead of 8). Like other miniature species, P. amanuensis also reduced chemotaxis of some cranial elements and reduced the physical and digital structures of the hands and feet. Paedophryne amanuensis is distinguished morphologically from other members of the genus, P. kathismalphlox, P. oyatabu and P. swiftorum, through its extremely small snout length of 7.0 – 8.0 mm and moderately long legs with tibia to snout length. The length ratio ranges from 0.478 – 0.507. It is further distinguished from P. oyatabu and P. swiftorum by having a longer, narrower head, and from P. kathismaphlox by having a wider and shorter head. Finally, P. amauensis can be further distinguished from P. swiftorum through its higher calling frequency, which ranges from about 8400 – 9400 HZ and consists of single notes rather than eight compound notes (Rittmeyer et al. al. 2012).
The dorsal surface of P. amanuensis is dark brown with some gray to rusty brown spots. The lateral and ventral surfaces of the frogs are dark brown to slate gray with irregular bluish-white spots (Rittmeyer et al. 2012).
Life history, richness, activities and distinctive behavior
These frogs are amphibians and live on land. Like most miniature frogs, P. amanuensis lives in tropical moist forest leaves to compensate for their sensitivity to water loss. They are also said to reproduce through direct development. However, since only males were observed, the details of their reproductive behavior are unknown. In general, miniature frogs lay fewer, larger eggs than their counterparts (Rittmeyer et al. 2012).
These frogs can mainly hear sunrise and sunset calls from the leaves in the primary forest. Their call consists of a continuous sequence of high notes lasting 2 – 14 ms, produced at a rate of 1.5 notes/second and having a dominant frequency between 8400 – 9400 Hz. Calls last for 1 – 3 minutes with a short break of 3.3 – 40.8 seconds before starting again. One male made 355 calls in four groups in 5.5 minutes. These calls sound similar to those made by insects (Rittmeyer et al. 2012).
Paedophryne amanuensis feeds on small invertebrates, such as acarians and collembolans. Because of its small size and relatively common abundance, P. amanuensis may be an important member of tropical moist forest ecosystems (Rittmeyer et al. 2012).
As a small species, P. amanuensis is likely to be more susceptible to predation by invertebrates, which may explain its absence in aquatic habitats and its tendency to live in upland areas where few are found. invertebrates than lowland (Rittmeyer et al. 2012).
