Paedophryne amauensis
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Paedophryne amauensis , on a dime (coin 17.91 millimeters in diameter) |
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| Rittmeyer , Allison , Gründler , Thompson & Austin , 2012 |
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PAEDOPHRYNE AMAUENSIS is a frog of the family -mouthed . It was discovered in Papua New Guinea in August 2009, but was not described for the first time until January 2012. With a head-trunk length of 7 to 8 millimeters, it is the smallest vertebrate in the worldthat has been described so far.
description
Scale
The small size of the frog Paedophryne amauensis with a length of 7 to 8 millimeters has sparked discussions about where the limits in the ratio of volume to surface area for a terrestrial vertebrate could be so that a regulated metabolism can still be maintained. Above all, the release of water through the skin could be a limiting factor. The outer surface plays a less important role in aquatic life. The fish Paedocypris progenetica , the females of which are 7.9 millimeters in length, was previously considered the world's smallest free-living vertebrate, but is being replaced by Paedophryne amauensis . The males of the deep-sea frogfish Photocorynus spiniceps , which had already been described by Regan in 1925, reach a length of only 6.2 millimeters, but these dwarf males would not be viable on their own, but parasitize on the much larger, 46 millimeter long females.
features
The back color of Paedophryne amauensis is dark brown with irregular rusty brown spots. The flanks and the belly are mottled dark brown to slate gray and bluish white. The first phalanges of fingers and toes are reduced to a single one. There are only seven vertebrae in front of the sacrum , unlike most of the other members of the Papuan narrow-mouth frog subfamily . The second and fourth fingers as well as the second and fifth toes are also reduced. The mouth is relatively wide and short, the eyes are relatively large.
Similar species
This species of frog differs from related species of the genus Paedophryne , which also occur in Papua New Guinea, mainly by their smaller size (7–8 millimeters) and longer legs. In December 2011, the two species Paedophryne dekot and Paedophryne verrucosa were described by Fred Kraus from the Bishop Museum in Hawaii. In the case of Paedophryne dekot , a head-torso length (SVL) of 8.5–9.0 millimeters was measured in females; males have not yet been discovered. The females of Paedophryne verrucosa reach a length of 8.8–9.3 millimeters, the males 8.1–8.9 millimeters. In 2010, Fred Kraus described the first two types of Paedophryne . They become a little longer than an inch. In Paedophryne cathismaphlox , the females reach 10.4–10.9 millimeters in length, the males around 10.1 millimeters. Paedophryne oyatabu becomes even larger, the females of this species reach 11.3 millimeters. Also in the work by Rittmeyer et al. 2012 newly described species Paedophryne swiftorum becomes 8.3–8.9 millimeters long.
distribution
The occurrence of Paedophryne amauensis is restricted to Papua New Guinea. The specific epithet amauensis refers to the village of Amau in the Central Province of Papua New Guinea , located near the first site .
Way of life
The habitat of this species of frog is not tied to the presence of water. It lives on the ground in fallen leaves. There is no tadpole stage , the young frogs hatch fully developed from the egg. It is believed that the clutch of this species only consists of one or two eggs. How often eggs are laid per year has not yet been investigated. In any case, a small number of eggs per clutch only results in slow population growth . If there are cuts in the population dynamics, these can only be compensated for slowly.
Paedophryne amauensis is crepuscular. The calls of the males only sound at dawn or dusk. The call height is between 8400 and 9400 Hertz and is similar to the stridulation of insects.
The small size of these animals poses not only anatomical , but also physiological problems. Paedophryne amauensis has a very large skin surface in relation to its volume. Therefore dehydration is one of the greatest dangers for this terrestrial vertebrate. However, living in the moist foliage on the floor of the tropical rainforest offers these frogs an ecological niche to which they are well adapted. Due to their small size and the camouflage color adapted to the withered leaves, they are difficult to perceive by predators and researchers alike. In 2009 they were discovered by Christopher Austin and Eric Rittmeyer from Louisiana State University only because of their acoustic signals.
Individual evidence
- ^ A b Eric N. Rittmeyer, A. Allison, MC Gründler, DK Thompson, Christopher C. Austin: Ecological Guild Evolution and the Discovery of the World's Smallest Vertebrate. PLoS ONE 7, 1, e29797, January 2012 doi : 10.1371 / journal.pone.0029797
- ↑ Species diversity: The newly discovered frog is the smallest vertebrate in the world. Zeit Online January 12, 2012, accessed January 12, 2012
- ↑ CT Regan: Dwarfed males parasitic on the females in oceanic angler-fishes (Pediculati Ceratioidea). Proceedings of the Royal Society of London, Series B - Biological Sciences, 97, B684, pp. 386-400, 1925
- ↑ E. Schraml: The smallest vertebrate on earth ... or the very smallest or the very smallest? Aquaristik aktuell, 15, 5, pp. 56–60, 2007
- ↑ Masaki Miya, Theodore W. Pietsch, James W. Orr, Rachel J. Arnold, Takashi P. Satoh, Andrew M. Shedlock, Hsuan-Ching Ho, Mitsuomi Shimazaki, Mamoru Yabe & Mutsumi Nishida: Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective. BMC Evolutionary Biology, 10, 1, 58, February 2010 doi : 10.1186 / 1471-2148-10-58
- ↑ Fred Kraus: At the lower size limit for tetrapods, two new species of the miniaturized frog genus Paedophryne (Anura, Microhylidae). Zoo Keys, 154, pp. 71-88, December 2011 doi : 10.3897 / zookeys.154.1963
- ↑ Fred Kraus: New genus of diminutive microhylid frogs from Papua New Guinea. Zoo Keys, 48, pp. 39-59, 2010 doi : 10.3897 / zookeys.48.446
- ↑ Jeanne E. Young, Keith A. Christian, A. Donnellan, CR Tracy & D. Parry: Comparative analysis of cutaneous evaporative water loss in frogs demonstrates correlation with ecological habits. Physiological and Biochemical Zoology, 78, 5, pp. 847-56, 2005
literature
- EN Rittmeyer, A. Allison, MC Gründler, DK Thompson, CC Austin: Ecological Guild Evolution and the Discovery of the World's Smallest Vertebrate. PLoS ONE 7, 1, e29797, 2012 doi : 10.1371 / journal.pone.0029797 (first description)
Web links
- Biodiversity: The newly discovered frog is the smallest vertebrate in the world. Zeit Online January 12, 2012, accessed January 12, 2012