All dart frogs from the Phyllobates genus are native to South America, they occur from Nicaragua to Colombia. Within the genus Phyllobates is the most poisonous species of frog Phyllobates terribilis or the Golden Poison Dart Frog. Terribilis are typical of poison dart frogs, in that they are colourful with varying degrees of toxicity. Only species of Phyllobates are used by natives of South American tribes as sources of poison for their blow pipe darts. The most toxic of the many poisonous alkaloids these frogs emit from their skins is batrachotoxin, but there are a wide number of other toxic compounds which are secreted by these frogs.
There are five members within the Phyllobates group.
Map showing species ranges
Discovered in 1978 by Myers, Daly, and Malkin Phyllobates terribilis is found in lowland rainforest (100-200 meters elevation) of pacific coastal Colombia. It occurs in rough, hilly landscapes at the western foot of a northerly inclined spur of the Cordillera Occidental. The humid forest is believed to receive at least 5 meters of rainfall per year and the forest is broken as a result of stream dissection. The forest tends to be open on gravel slopes that are usually wet due to seepage; slopes tend to be steep and hillside soils are often covered in gravel. Leaf litter is reported to be sparse. The main ground vegetation is composed of saplings and treelets, small palms, herbaceous plants and ferns.
Terribilis are not usually found in secondary growth forest and cultivated areas as they prefer primary growth forest, making them susceptible to habitat change due to commercial land use. They are uncommon along larger streams in their range, due to development in the form of commercial crop fields, or secondary growth from previous forest resource utilization. Major threats to the species include pollution from illegal spraying of crops, and habitat loss through deforestation.
With its high toxicity terribilis seems to have few predators and only the snake Leimadophis epinephelus has ever been recorded taking terribilis as a regular prey species. This snake appears to be a key predator of other frog species and research indicates that it has resistance to several anuran toxins which allows it to also prey on Atelopus zeteki, Atelopus elegans and Dendrobates auratus. Being a relatively small snake (max length 50cm) it probably predates only juvenile P. terribilis and not the adult frogs which are much larger and contain a much higher toxin yield.
Terribilis is one of the largest poison dart frogs at 47mm as an adult. This frog is capable of taking much larger prey than other dendrobatids and will take feeder insects as large as a full-grown cricket. They naturally occur in three morphs: mint green, yellow, and orange. These colours are variable including a light yellow cast to orange frogs or silver "green" individuals.
Phyllobates terribilis is a large frog in dendrobatid terms with adult females achieving a maximum SVL (snout-vent length) of 47 mm, and adult males reaching 45 mm in SVL. Males mature at 37 mm while females mature around 40-41 mm.
Sexing terribilis can be quite problematic. Toepads aren't useful and body size and shape can be very misleading. Keep in mind that terribilis also take around 18 months or longer to reach sexually maturity. The only way to confirm sex for sure is by - loud calling (definite male) eggs in viv (definite female) tapoles being carried (definite breeding pair).
Terribilis in Captivity
Terribilis are large, hardy frogs that originate from cool rainforest areas in Colombia. This should be reflected with the temperature range which should be from 65-78ºF. Terribilis are very sensitive to temperatures higher than 80ºF which can prove fatal if maintained for any length of time. They need a humid vivarium but not a wet vivarium terribilis are susceptible to skin problems especially foot sores if kept too wet.
We always provide flat rocks for them to ‘hang out on’ which they regularly do. Humidity should be maintained at 80% or higher.
Terribilis are one of the easiest dart frogs to feed as adults can swallow a diverse range of feeder insects. We use hydei, melongaster, waxworms, phoenix worms, native woodlice, house flies and during spring and summer ‘field plankton’ figures highly in their diet.
Terribilis are very terrestrial during the day but we find that they climb at night and sleep in favourite individual ‘nests’ at the very top of the viv.
Terribilis can be slow to reach sexual maturity which occurs between 12-18 months of age. Courtship begins with the male calling loudly and continually to the female. We provide huts and more natural ‘caves’ with petri dishes inside which they use for laying.
The Female usually lays eggs with the male in attendance who fertilizes them immediately after laying. We leave the eggs inside the enclosure for 24 hours before removing them to the incubator. The average clutch size is from 8-18eggs. The temperature determines how soon the eggs hatch, usually around 10 days or so.
We keep our tadpoles of the same age and size in large communal tanks and find they do well in this environment. We have also found that larger tadpoles can be cannibalistic if smaller tadpoles are introduced to the tank.
Juvenile frogs are primarily black in colour, with metallic gold dorsolateral stripes. As the frogs reach maturity they undergo an ontogenetic colour change where the dorsolateral stripes disappear and the body becomes a more brightly coloured golden yellow. This occurs around 18 weeks; the ventral colouration takes another several weeks to reach the same bright colour. Terribilis reaches its adult size in just over a year with adult coloration being gained fairly early.