Nurse Shark
Shallow coral and rocky reefs, sand flats, seagrass beds and mangrove channels from intertidal pools to ≈ 70 m; in Costa Rica abundant around Isla del Caño, Golfo Dulce, Bahía Culebra, and Caribbean patch reefs of Cahuita.
Small diurnal dendrobatid (SVL 18–40 mm, mass ≈ 1–3 g) with smooth, glandular skin containing alkaloid toxins. Ground colour black or dark chocolate overlain by bright green, turquoise or mint-blue irregular blotches; Pacific morphs often bronze-black with lime spots. Digits bear expanded adhesive discs; toes basally webbed. Iris dark; tympanum distinct. Females generally 10 % larger. Tadpoles grey-brown with high fins and conspicuous eyes. Colour changes little after metamorphosis.
Females larger; males have swollen third-finger pads and produce 3-kHz trilling calls.
Males 2.2 cm; females 2.5 cm SVL
≈ 2 g
4–8 yr wild; up to 12 yr captivity
No data
No data
≈ 9–12 mo
Extended rainy season (May – Nov)
Eggs hatch 7–12 d; tadpoles metamorphose 6–8 wk
Small diurnal dendrobatid (SVL 18–40 mm, mass ≈ 1–3 g) with smooth, glandular skin containing alkaloid toxins. Ground colour black or dark chocolate overlain by bright green, turquoise or mint-blue irregular blotches; Pacific morphs often bronze-black with lime spots. Digits bear expanded adhesive discs; toes basally webbed. Iris dark; tympanum distinct. Females generally 10 % larger. Tadpoles grey-brown with high fins and conspicuous eyes. Colour changes little after metamorphosis.
Humid lowland & premontane rain forest (0–800 m) on both coasts; abundant in shaded cacao/banana plantations and secondary forest near permanent water.
Diurnal leaf-litter insectivore specialising on formicine ants & mites—the alkaloid source.
Males defend 1–2 m² leaf-litter territories; aggressive wrestling common.
Courtship involves tactile nudging to suitable oviposition site (leaf axil).
Male guards eggs, hydrates clutch; carries tadpoles to tree-holes/bromeliads
Exhibits Müllerian mimicry with Oophaga pumilio where ranges overlap.
Tadpoles are omnivorous cannibals if multiple share a pool.
Male territorial call rate increases after rain-onset acoustic cues.
Native
Decreasing
Shallow coral and rocky reefs, sand flats, seagrass beds and mangrove channels from intertidal pools to ≈ 70 m; in Costa Rica abundant around Isla del Caño, Golfo Dulce, Bahía Culebra, and Caribbean patch reefs of Cahuita.
