Pencil Urchin (Eucidaris Tribuloides)

Species Name : Eucidaris Tribuloides

Care Level : Moderate

Temperament : Peaceful

Color : Black, Red, Tan, White

Diet : Omnivore

Reef Compatible : No

Water Conditions ; 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.023-1.025

Max. Size : 5"

Origin : Caribbean, Philippines

Family : Cidaridae

The Pencil Urchin (Eucidaris Tribuloides) of the Eucidaris genera is also known as the Mine or Club Urchin.

The Pencil Urchin is a small, spherical hard shelled sea animal covered in mildly poisonous protective spines.It has a brown, sometimes mottled body with stubby, thick spines radiating out in all directions. The spines are surrounded by basal plates. Never try to pry it out of a hole, as you will break its spines before it lets go. As it ages, its spines may become covered with coralline and other types of algae. Spines can be regenerated if broken or lost.

It requires an aquarium with multiple hiding places and live rock on which it can graze. The rock formations should be sturdy, since the Urchin could dislodge rocks as it moves around the tank.

This is a very hardy, long-lived species that is fairly reef safe, though it may knock over small animals not securely attached to some form of substrate. During the day it will seek shelter in the rocks; at night it will come out and forage for food, looking particularly for algae lawns and smaller invertebrates like sea squirts or sponges. It can be destructive to corals.

The Pencil Urchin is very sensitive to high levels of copper-based medications and will not tolerate high levels of nitrates. If water conditions are poor, it will shed its spines.

It is extremely difficult to breed in an aquarium and has no distinguishing characteristics to help differentiate it from its mate.

It should be offered dried seaweed and some animal-based supplemental foods.

Size: Small: 1" to 1-1/2"; Medium: 1-1/2" to 2-1/2"; Large: 2-1/2" to 3-1/2"