Monte Iberia frogs
| Monte Iberia frogs | ||||||||||||
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Monte Iberia frogs ( Eleutherodactylus iberia ) |
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| Eleutherodactylus iberia | ||||||||||||
| Estrada & Hedges , 1996 |
The Monte Iberia frog ( Eleutherodactylus iberia ) is a frog belonging to the genus of the Antilles whistling frogs ( Eleutherodactylus ) . It lives endemically in a narrowly defined rainforest area on the Caribbean island of Cuba .
With a body length of around one centimeter, the Monte Iberia frog has long been the smallest known amphibian in the world and one of the smallest land vertebrates (tetrapoda) on earth, alongside the Brazilian saddle toad Brachycephalus didactylus . In late 2011 and early 2012, several even smaller species of the genus were Paedophryne of the family mouthed described, including PAEDOPHRYNE AMAUENSIS with only 7 millimeters head-body length .
features
When fully grown, this Cuban pygmy frog reaches a head-torso length of approx. Ten millimeters - males remain slightly below that, while females grow up to 10.5 mm long. Their skin is slightly wrinkled on the top and has no dorsolateral glandular ridges. The head is as long as it is wide and also about as wide as the torso. The eardrum , just behind the eyes equipped with horizontal pupils, is rounded and larger in the males than in the females, whose eardrum is also higher than it is wide. There is a little noticeable fold of skin above it. The ends of the fingers and toes are rounded and very thin. A vomerine dentition is - in contrast to larger representatives of the genus - not present.
The animals have a dark brown basic color, which is broken up by a vividly contrasting line pattern. Viewed from above, this stripe runs along the outline of the body from the tip of the snout over the eyes dorsolateral to the roots of the hind legs. There is also such a distinctive bright longitudinal line on the arms and legs. Their color changes depending on the body region between golden yellow (above the eyelids, on the arms) and white (abdomen, legs). The deep purple color of the belly is separated from the dark brown color of the flanks by an irregular white line.
distribution and habitat
The Monte Iberia frog only lives in a small rainforest area in the east of the island of Cuba ( Holguín province ). The holotype is found in Arroyo Sucio (Anacleto) Arriba on the western slope of Monte Iberia , at 600 m above sea level. Another described site is near Nibujón at sea level. The area is protected as the " Parque Nacional Alejandro de Humboldt ".
The species lives in the litter layer of the forest between fallen leaves and roots and feeds on small invertebrates , preferably mites and ants . She was observed both during the day and at night. The area is characterized by high annual precipitation of> 1600 mm and year-round high humidity.
Reproduction and development
As is characteristic of other miniaturization-prone species of frogs, the males' mating call consists of very high-frequency sounds - in this case around 5.78 kHz . It is also typical that a direct development takes place within the eggs deposited on land, i.e. without an interim aquatic tadpole stage . The females of the Monte Iberia frog apparently lay only one egg at a time. Maybe they are guarding this too.
Skin toxins
The Monte Iberia Eleuth may well such as the poison dart frog skin toxins secrete. Fat-soluble alkaloids were found in the frog's skin, including six pumiliotoxins and two indolizidines . These protect it against bacterial and fungal attack and against predators. The vivid colors of the stripes along the body's outlines are intended to signal to enemies that the frog is inedible. This enables him to go looking for food during the day too. Being seen is not a disadvantage in this case.
The Eleutherodactylidae family, to which the Monte Iberia frog belongs, is thus one of the five different frog families in which skin toxins occur. However, the frogs cannot synthesize the poisons themselves ; they ingest them with their food. Analyzes of the stomach contents of the Monte Iberia frog have shown that it feeds primarily on mites . In the specimens examined, the mites made up more than 70 percent of the diet. A large part of it belongs to the group of horn mites , some species of which can produce a pumiliotoxin, as released through the skin by the Monte Iberia frog.
External system
The species-rich family of southern frogs (Leptodactylidae), to which the Antilles whistling frogs ( Eleutherodactylus ) were counted for a long time, is now understood as paraphyletic based on genetic studies and can therefore be divided into several monophyletic groups. Eleutherodactylus is now - with approx. 180 instead of the former over 700 species no longer as comprehensive as before - with a few other genera in a separate family Eleutherodactylidae. Within the newly composed genus Eleutherodactylus , several sub-genera are also differentiated; the Monte Iberia frog is counted to the subgenus Euhyas .
Danger
Eleutherodactylus iberia is sensitive to negative environmental changes due to its limited range in Cuba. Despite the formal protection status by the " Alexander von Humboldt National Park ", the habitat is seriously endangered by deforestation (wood and land reclamation). In addition, there is the mining of mineral resources such as chromium and possibly nickel in the future, as well as pollution from environmental toxins such as pesticides . The Monte Iberia frog, which was only discovered in 1993 - with "the smallest frog in the world" - is therefore classified by the IUCN as "critically endangered" (threatened with extinction).
swell
The article in the version of 2/3. June 2009 was created on the basis of the following website, unless otherwise indicated by individual references:
- Species portrait at Amphibiaweb (Engl.)
Individual evidence
- ↑ a b Amphibiaweb: Family Eleutherodactylidae (Engl.)
- ↑ Distribution map at www.iucnredlist.org
- ↑ Ariel Rodríguez, Dennis Poth, Stefan Schulz and Miguel Vences: Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba. Biology Letters, Royal Society Publishing, online publication on November 3, 2010 doi : 10.1098 / rsbl.2010.0844 full text (English)
- ↑ American Museum of Natural History: "Amphibian Species of the World" (Engl.)
- ↑ IUCN Redlist: Eleutherodactylus iberia (Engl.)
