|Dendrobates t. tinctorius|
Dendrobates tinctorius, also known by the common name dyeing dart frog, is a species of poison dart frog. It is the among the largest species, reaching lengths of 50 millimetres (2.0 in). This species is distributed throughout the eastern portion of the Guiana Shield, including parts of Guyana, Suriname, Brazil, and nearly all of French Guiana.
Like most species of the genus Dendrobates, D. tinctorius is a mildly toxic species of poison dart frog. It produces pumiliotoxins which the frog uses for self-defense. While pumiliotoxins are weaker than their derivative allopumiliotoxins and the batrachotoxins secreted by Phyllobates species, they are sufficiently toxic to discourage most animals from feeding on dendrobatids. In the case of D. tinctorius, the toxins cause pain, cramping and stiffness when the frogs are handled roughly. Due to the toxins of the frogs, animals that feed on D. tinctorius will typically learn to associate the bright colours of such frogs with the vile taste and pain that occurs after a frog is ingested. As it is such a variable species, different color morphs of tinctorius have varying degrees of toxicity.
Local tribes use D. tinctorius for decoration. Feathers are plucked from the back of young parrots and the frogs are rubbed on the parrots' exposed skin. When the feathers regrow, the toxin causes them to appear yellow or red rather than green. These altered feathers are highly prized by the indigenous tribes.
The dyeing poison dart frog is large for a poison dart frog, but may be smaller than Phyllobates terribilis and Ameerega trivittata. Many small forms of D. tinctorius reach 3.5 cm long; most morphs are in the area of 5 cm in length or slightly bigger; some of the larger morphs may exceed 7 cm, although large tinctorius are usually closer to 5.5 cm long. For some time it was thought that captive individuals were incapable of reaching the sizes of wild specimens; however later evidence suggested that the fact that captive individuals do not reach their maximum potential size may be due to vitamin and mineral deficiencies. More recently, breeders have had success raising tinctorius to very large sizes.
Dendrobates tinctorius is one of the most variable of all poison dart frogs. Typically the body is primarily black, with an irregular patter of yellow or white stripes running along the back, flanks, chest, head, and belly. In some morphs, however, the body may be primarily blue (as in the 'azureus' morph, formerly treated as a separate species), primarily yellow, or primarily white. The legs range from pale blue, sky blue or blue-gray to royal blue, cobalt blue, navy blue, or royal purple and are typically peppered with small black dots. The yellow-backed morph is almost entirely yellow and black, with only a few specks of white on the toes. Another unique morph, the Citronella morph, is primarily golden yellow with tiny splotches of black on its belly and royal blue legs that have no black dots.
Males are typically smaller and more slender than females, but they have larger toe discs. The toe discs of female dyeing poison dart frogs are circular while those of the males are heart-shaped.
It exists in discrete patches throughout this region, being restricted to "highland" (up to 350 metres (1,150 ft)) areas. While this species can be found at sea level, these individuals have been collected at the base of nearby hills or mountains. The isolation of populations has presumably occurred as a result of the erosion of these highland areas and the seasonal inundation of the inter-patch areas.
The specific name tinctorius comes, however, not from the variety of colors, but from the way some indigenous tribes use the frogs. They rub them on the skin of young parrots, and the toxifying of the bird's skin causes them to grow feathers of different colors.
- Gaucher & MacCulloch (2004). Dendrobates tinctorius. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 12 May 2006. Database entry includes a range map and a brief justification of why this species is of least concern