Pink Pin Cushion Urchin

Sea Urchins are incredible powerhouses when it comes to clearing algae out of a reef. These echinoderms, related to starfish, venture around on their countless tube feet as they use their small, conical ring of ‘teeth’ to scrape algae, sponges, and other particulate foods off of most tank surfaces. Urchins are typically quite active and ravenous, and a single individual can make a huge impact on the presence of both encrusting and filamentous algae in both reef and fish-only systems. While reef-safe, it is highly recommended that any loose corals be glued down, as sea urchins in general have a tendency to accumulate objects to use as a sort of ‘cover’ from predators. If considering introducing an urchin to a fish-only system, be aware that some larger wrasse, trigger and puffer species are capable of consuming urchins.

Quick Care Guide

Care Level: Easy
Minimum Tank Size: 30 gallons
Temperament: Peaceful
Diet: Herbivore
Reef Safe: Yes, with caution
Adult Size: About 3 inches across
Region: Western Atlantic and Caribbean
Scientific Name: Lytechinus variegatus

About the Pink Pin Cushion Urchin

This pink pincushion urchin is a color form of Lytechinus variegatus, a short-spined grazer from the seagrass beds and reef flats of the Caribbean. Its dense covering of short, soft pink spines gives it the rounded pincushion look that makes it a popular pick for reef aquariums.

Tank Requirements

Add pincushion urchins to an established aquarium with visible algae growth and plenty of rock surface to graze. Allow roughly one urchin per 30–50 gallons so each has enough food.

Diet and Feeding

Pin cushion urchins scrape film algae, hair algae, and diatoms from rock and glass. They will also graze coralline algae. Once nuisance algae is under control, supplement with dried seaweed clipped near the urchin or sinking algae wafers several times per week to prevent starvation.

Temperament and Tankmates

This urchin is peaceful and safe with fish, shrimp, crabs, and snails. Avoid triggerfish, puffers, large wrasses, and harlequin shrimp, all of which may prey on urchins.

Reef Compatibility

The Pink Pin Cushion Urchin is reef safe with caution. It does not eat corals, but it may carry off or knock over loose frags as it moves. Glue frags securely and expect some coralline algae grazing.

Water Parameters

Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Urchins are sensitive to low or fluctuating salinity. Drip acclimate slowly and keep specific gravity stable. Invertebrates are highly sensitive to copper, and copper-treated water or medications should never be added to an aquarium that houses them.

Common Considerations

• Covering behavior is normal: Carrying shells, rubble, or algae on its spines is natural and harmless.

• Spine loss is a warning sign: Dropping spines usually points to stress or poor water quality.

• Supplement when algae runs out: A hungry urchin will decline quickly without added food.

• Glue down frags: Loose corals may be moved or toppled.