It is monotypic in the genus Minyobates. have only one species : Minyobates steyermarki
Minyobates steyermarki (formerly Dendrobates steyermarki) is a species of frog in the family Dendrobatidae endemic to Cerro Yapacana in southern Venezuela. It is also known by the common names of demonic poison frog, demonic poison-arrow frog, or Yapacana's little red frog. It is monotypic in the genus Minyobates.
Its natural habitat is montane tepui forest where it is common in terrestrial habitats among moss-clad rocks and breeds in bromeliads. Threats to this species include open pit gold mining, collection for the pet trade (and occasionally, for scientific purposes), and possibly wildfires, and the IUCN has assessed it as being "critically endangered".
Critically Endangered (IUCN 3.1)
Dendrobates steyermarki Rivero, 1971
Minyobates steyermarki is a small frog, growing to a maximum snout-to-vent length of 19.5 mm (0.8 in) but more typically being shorter than 17 mm (0.7 in). The head is broad with a partially truncated snout and an angular ridge between the eye and nostril. The front limbs are long and slender and all the fingers have discs at their tips. The first digit on the hand is longer than the second one, and the third and fourth digits have discs larger than the other two. The toes also have discs but these are smaller than those on the hands. The toes are unwebbed. The skin is finely granulated on the throat and flanks but smooth elsewhere. The dorsal surface is bright red, dull red or reddish-brown and liberally speckled with small black spots. The limbs are a similar colour to the body or may be salmon-pink. The underparts are also similar but have rather larger dark blotches.
Distribution and habitat
This has an altitude of up to 1,345 m (4,413 ft) whereas the surrounding rainforest is at 80 metres (260 ft) above sea level. The plateau is entirely in the Yapacana National Park. The area has heavy rainfall and the temperature varies between 13 and 27 °C (55 and 81 °F).
Minyobates steyermarki is a mainly terrestrial species and is found in wooded areas with trees 8 to 10 metres (26 to 33 ft) high, in rocky places where moss abounds. Breeding takes place in the water that collects in leaf axils and in the water-filled rosettes of bromeliads.
The International Union for Conservation of Nature has assessed Minyobates steyermarki as being "critically endangered". This is because its total range is under 10 square kilometres (3.9 sq mi) and, although it was said to be very common on the tepui in 1999, its numbers appear to be decreasing. Wildfires could have serious consequences for this species, its forest habitat is threatened by opencast gold mining and specimens have been removed illegally for research.
Minyobates steyermarki is known only from Cerro Yapacana in Venezuela. This is a tepui or table-top mountain, a raised plateau that rises abruptly from the flat land between the Orinoco and Ventuari Rivers.
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Care articles :
- Minyobates steyermarki (RIVERO , 1971) :
courtesy : www.dendrobase.de/index.php
Dendrobates steyermarki (R IVERO , 1971)
Minyobates steyermarki (M. YERS , 1987)
Dendrobates steyermarki (JUNGFER , LÖTTERS & JÖRGENS , 2000)
Minyobates steyermarki (VENCES , KOSUCH , BOISTEL , HADDAD , LAMARCA , LOTTERS & VEITH , 2003)
English name: Demonic Poison Frog, little red frog of Yapacana
German name: Table Mountain-tree climber
Spanish name: Sapito rojo del Yapacana
Type find location of the first description :
"Cerro Yapacana, 1,200 m., Territorial Federal Amazon, Venezuela". After F ROST (2004)
Only known from the type find site of the Cerro Yapacana in the south of Venezuela on the border with Brazil. The animals live in a less than 10 square kilometers forest area in 600-1200 m altitude.
Amphibia-> Anura-> Dendrobatoidea-> Dendrobatidae-> Dendrobatinae-> Minyobates -> Minyobates steyermarki (R IVERO , 1971)
Note to the scheme:
The genus Minyobates was established by M YERS in 1987. Type species is Minyobates steyermarki . The other small species of the former Dendrobates minutus group of SILVERSTONE (1975) Ranitomeya abdita, R. altobueyensis, R. bombetes, R. fulgurita, R. minuta, R. opisthomelas and R. viridis were also from the ancient genus Dendrobates with in the new genus transferred. The demarcation to Dendrobates was due to morphological features (small size <20mm, Dendrobates > 20mm), the absence of histrionicotoxins in skin toxins and a mating head amphora in M. steyermarki(M YERS , 1987). It has now been confirmed that the composition of skin toxins depends mainly on the prey consumed (S APORITO ET AL. , 2004). Even within different variants of a species, this can vary greatly. Therefore, the skin poison composition can no longer be used as a systematically usable feature. The Kopfamplexus is considered as original behavior within the family Dendrobatidae and just its absence as typical of the modern genus Dendrobates . Thus, the establishment of a new genus for the species M. steyermarki from M YERS point of view was quite justified. Later ethological investigations on other small species the M YERSHowever, due to their small body size, Minyobates showed that there is no Amplexus in R. minuta and R. fulgurita . Your courtship is exactly like other typical representatives of the subfamily Dendrobatinae . Even with M. steyermarki a head ampoule could only be observed in the terrarium with aggressive behavior. The courtship also runs here as in most species of the subfamily Dendrobatinae without Amplexus and with separate delivery of sex products (B RANDT pers. Komm.). J UNGFER ET AL.(1987, 2000) questioned the genus and did not recognize the genus rank. Genetic studies of V ENCES ET AL. (2003) show, however, that M. steyermarki genetically deviates so much from Dendrobates that for this species the genus Minyobates was validated again and is now considered a sister genus to Dendrobates . So far, however, the genus is monotypic, that is occupied with only one kind. For the other small species, which were made by M YERS to Minyobates , since the extensive revision of F ROST ET AL . (2006) now the genus affiliation to Ranitomeya B AUER, 1988.
Annex II of the WA. Annex B of the EUArtschVO. Notifiable according to BArtSchVO.
According to IUCN (2005), M. steyermarki is considered critically endangered. The classification was due to the small distribution area of less than 10 square kilometers on the Cerro Yapacana, the fact that it is the occurrence of the only known population and the fact that the forest area as a habitat continues to decline. In the biotope, the species is still occurring in large quantities. Inventory not decreasing.
Very small type with a KRL of 14-16mm.
Body rusty brown to dark red, partly with indistinct dark brown markings. Skin smoothly granulated on the flanks. Adhesive discs of the fingers widened. Finger 1> 2. Females with larger body size and greater total length, males slightly smaller (B RAND & S CHMIDT , 2003)
There is only one variant known so far.
So far no information. Probably 5-7 years possible.
According to B, males begin to call RAND & S CHMIDT (2003) with about 8 months. Fertilized clutch but only after about 12 months.
- Skin poisons:
According to M YERS (1987), the main components of the skin toxin pumiliotoxin -A, decahydroquinoline and indolizidine but no histrionicotoxin
Clutch and larvae
- Features of scrim:
According to B RAND & S CHMIDT, the gel mass has a diameter of approx. 15 mm and contains 3-9 eggs (Ø 4 eggs). The eggs are initially black, then light up slightly.
- Characteristics larvae:
After hatching 8-10 mm in size (B RAND & S CHMIDT , 2003).
- Development periods:
Clutches require 10-14 days at 20 ° C. Higher temperatures affect the development negatively. Larvae need about 70 days to complete at 22-26 ° C metamorphosis The hind legs are easily recognizable after 35-42 days and after about 70 days the front legs break through. Freshly metamorphosed frogs have a size of about 8-10 mm. They have only two weak to strong red Dorsalstreifen Until sexual maturity at about 12 months, these strips grow to a continuous color (B RAND & S CHMIDT , 2003).
The larvae are omnivorous and can be well raised with mixtures of commercially available ornamental fish feeds. A finely ground mixture of ornamental dry fish food (color food), freeze-dried crab crayfish, red mosquito larvae, water fleas, Artemia and spirulina-containing feeding tablets for ornamental fish seems well suited (O STROWSKI , personal observation).
- General behavior:
Quiet a bit shy frog.
There are no observations on field behavior in the field. The animals are quite aggressive in the terrarium. The aggressiveness is not gender specific. With group keeping of wild caught already losses occurred with suppressed animals! The animals jump each other and cling in a head ampoule (B RANDT , pers. Komm.).
- courtship behavior:
The courtship behavior has not yet been documented in detail. According to B RANDT (personal comm.) Comes quite quickly after calling for spawning. B Rand observed a "lead" by the male. The male attracts the female to the oviposition site with constant shouting. At oviposition, B RANDT wasnever able to observe an amplexus as described by M YERS (1987). The animals sat mostly opposite. Oviposition and fertilization took place partially also as with Dendrobates separately.
- Brood care behavior:
There are no observations on observations from the field. In the terrarium, the male takes over the care of the eggs (paternal brood care). It usually transports all larvae together, but sets the tadpole separately in small phytotelma ta (eg Bromelienachseln) from. A supply of larvae with feeders could not be observed so far. (B RANDT , personal comm.)
- Utterance (vocalization):
The reputation is unique in the family Dendrobatidae. These are bird-like beeps. The sounds are delivered in single whistles. In the presence of several males forming Rufgemeinschaften, in which all males deliver their whistles synchronized succession. It comes to whistle-series in which one can make the calls of a single male difficult (B RANDT , pers. Komm.)
Distribution area Minyobates steyermarki
There is little information about the biotope. It concerns tropical rainforest of the low and premontane stage (lowland and mountain rainforest). According to B RAND & S CHMIDT (2003), the animals are said to be found in soil bromeliads. According to IUCN (2005) also in Bromelien in the crown area. The population should be quite strong individuals.
The occurrence extends at altitudes of 600-1200 m. So it lies in the field of Tierra calienta at the transition to Tierra templada, Temperatures range from 18 ° C at higher altitudes to 24 ° C at lower altitudes. At higher altitudes, the daily fluctuation in the temperature between day and night is high and can reach up to 10 ° C. Cold spells with night temperatures of only 10 ° C are quite possible. In the southern region of Venezuela, the rainy season starts to decline in the months of January to March with precipitation falling below 50 mm (see Fig. 1). However, it is not a pronounced dry season. The humidity remains high year round.
Climate diagram of southern Venezuela in the
area of table mountains. Source: www.klimadiagramme.de.
© T. Ostrowski
Attitude in the terrarium :
Terrarium / Facility:
Rainforest terrarium from 40cm x 40cm x 40cm. Automatic irrigation and fog system recommended.
20-24 ° C, lower at 4-6 ° C at night. For breeding temperature drop needed. (after B RANDT & S CHMIDT , 2003)
70-80%, at lunchtime up to 70%, in the morning and in the evening 100% (fog)
Usual small food animals: Drosophila, micro-crickets, springtails, meadow plankton
Group keeping is possible due to the aggressiveness only with animals raised together. The best results are obtained with paired posture (B RANDT , pers. Comm.).
Tips for breeding:
For breeding, a strong short-term temperature reduction is absolutely necessary according to B RANDT(personal comm.). At permanently constant temperatures, no scrim is released. Even a permanently cool attitude does not lead to success. The animals can be kept permanently good at 24 ° C. As a spawning stimulant, however, a temperature drop of 5 - 7 ° C must occur (eg by venting). At the same time increasing the humidity, it then comes to increased calls and finally spawning. Clutches are sold in horizontal, dry photo boxes. Removed clutches develop better than in the terrarium leave. Larvae grow well with a mixture of dry food and freeze-dried insects. The young are growing rather fast and can be reared well in the group (BRANDT , personal. Come.).
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