Ephebopus cyanognathus – Blue fang tarantula

Ephebopus cyanognathus has a dark brown to black body and legs, often with paler rings at the joints. Its most distinctive feature is the chelicerae covered in iridescent blue setae, clearly visible when the spider sits in its burrow entrance.

Adult females measure about 5 cm in body length with a leg span of 10–12 cm. Males are slimmer, longer-legged and carry palpal bulbs after the final moult. Juveniles can be lighter and more contrasting.

The species was described in 2000 from a holotype from the Roura district of French Guiana. The World Spider Catalog gives the range as French Guiana, and it remains the only confirmed country. Other Ephebopus species are also known from Suriname, Guyana and Brazil.

A special feature of the genus is its urticating hairs on the pedipalps. The spider rubs them off with its chelicerae and can flick them towards a threat. This is a different mechanism from the abdominal hair-kicking of most South American tarantulas.

This is a burrowing species that builds deep, silk-lined tunnels. An adult female needs a floor of about 30 × 20 cm but a deep substrate layer of 15–20 cm. A mix of coco fibre with soil or peat holds tunnel shape well. A piece of cork or a half-tube pressed into the substrate helps the spider start its burrow.

In clear-walled enclosures the spider often runs a tunnel along the glass. That allows observation, but suddenly uncovering the tunnel stresses the spider. Keep juveniles in containers with deep substrate from the start, as they grow less well without the chance to dig.

Ephebopus cyanognathus comes from humid tropical forest. The ideal temperature is 24–28°C. The lower layers of substrate should stay moist while the surface may dry slightly. Water along the edge so moisture soaks down, rather than misting the burrow entrance.

Moist substrate must go hand in hand with ventilation. Overly wet, compacted substrate without air exchange encourages mould and mites, while young Ephebopus are sensitive to drying out, so steady, moderate moisture deep in the substrate is key.

The spider usually hunts from its burrow entrance and at night sits just outside it. Juveniles eat small crickets or roaches every 4–6 days, adults every one to two weeks. Offer prey near the burrow entrance and remove uneaten insects after a day.

Growth is moderate. Males usually mature within 2–3 years, females later. Before a moult the spider seals its burrow with silk and may stay out of sight for weeks, which is normal.

Ephebopus cyanognathus is nervous and fast. It reacts to disturbance by retreating into its burrow, taking a threat posture or biting, and it can flick urticating hairs from its pedipalps. Adults are rarely visible, so this is a species for keepers who value watching a burrow and feeding strikes more than a spider on display.

Do not dig the spider out without need. For rehousing, wait for it to come to the surface or carefully lift it out together with substrate into a container. Do maintenance with long tongs.