Mantella
Mantella (also known as golden frogs or Malagasy poison frogs) are a prominent genus of aposematic frogs in the family Mantellidae, endemic to the island of Madagascar.[1] Members of Mantella are diurnal and terrestrial, with bright aposematic coloration or cryptic markings.
Mantella are an example of convergent evolution—the independent evolution of a similar trait with species of a different lineage—with the Latin American family Dendrobatidae in size, appearance, and some behavioral characteristics. During the description of the first specimens from 1866 to 1872, Alfred Grandidier described both the brown mantella (Mantella betsileo) and Malagasy mantella (Mantella madagascariensis) and placed them within the genus Dendrobates based on their close resemblance.
This placement was heavily debated until 1882, when George Albert Boulenger created the genus Mantella after describing both Cowan's mantella (Mantella cowanii) and, in 1888, Baron's mantella (Mantella baroni). M. baroni was named after the gentleman that collected the specimens, Rev. Richard Baron, a missionary and botanist living in Madagascar. Baron was also interested in geology and herpetology, collecting many specimens during his extensive expeditions across the country. This species is incredibly similar in coloration to M. madagascariensis, except for the ventral/underside markings. In 1889, after the description of M. baroni, French naturalist Alexandre Thominot described Phrynomantis maculatus, with its type locality on Réunion Island. However, this locality was later corrected to the off-shore Malagasy islands of Nosy Bé and Nosy Komba and P. maculatus was synonymized with M. baroni.
The genus remained within Dendrobatidae until the late 19th century. The Royal Natural History (1893) by Richard Lydekker included the genus Mantella as one of two genera representing Dendrobatidae, saying that they could be "distinguished by the tip of the tongue being notched; while in Dendrobates of Tropical America the tongue is entire."[2]
During the first quarter of the 20th century, another three species of Mantella were described, including the golden mantella (Mantella aurantiaca), by the French herpetologist François Mocquard in 1900. In his work "Synopsis des familles, genres et espèces des reptiles écailleux et des batraciens de Madagascar" published in 1909, Mocquard gave a detailed description of Mantella and the species within the genus. Within the document, six species are described, including one unusual description of Mantella attemsi, described in 1901 by Franz Josef Maria Werner, an Austrian zoologist and explorer. Mocquard's work describes M. attemsi as follows: "First digit extends as far as the second. [Replilatero-dorsal] present, starting at the rear of the upper eyelid. Skin very porous, slightly rough on the back and the head, stomach side smooth; lower back of the legs very rough. Back a dark red-brown, rest of the body black."[3] This species was later synonymised with M. betsileo.
Species of this genus are small, varying in length between 18–31 millimetres (0.71–1.22 in).[4] Most Mantella species are sexually dimorphic in size, with females being larger than males. Mantella vary in shape from streamlined to plump/rounded bodies, with skin that is either smooth or granular. They have small, angular heads, with large eyes that are either entirely dark or have lighter coloration around the edge of the iris. Mantella have a very distinct tympanum. The tips or discs of the fingers are slightly enlarged, though those of the climbing mantella (Mantella laevigata) are distinctly larger than in other members of the genus. They have four fingers on each forelimb and five on each hindlimb; some species have webbed digits, while others do not. The tibiotarsal articulation is roughly between the shoulder and the nostrils.
