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Red Knob Sea Star
Please Note: Due to variations within species, your item may not look identical to the image provided. Approximate size range may also vary between individual specimen.
Red Knob Sea Star (Protoreaster linckii)
Additional locales and sizes may be available!

Quick Stats

Care Level Easy
Temperament Peaceful
Color Form Black, Red
Diet Carnivore
Reef Compatible No
Water Conditions 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.023-1.025
Max. Size 1'
Origin Africa, Indonesia, Maldives
Family Oreasteridae
Supplements Trace Elements
Compatibility View Chart
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The Red Knob Sea Star, also known as the Red Spine Star, African Sea Star, and Red-knobbed Starfish, has a thick, gray body with multiple bright red tubercles extending upward along each of its five arms. Red stripes connect these protrusions, giving its back the appearance of wires interconnecting in a grid-like fashion. It is found in shallow tidal pools and up to 100' deep reefs in the Indian Ocean.

The Red Knob Sea Star requires a large aquarium with ample supplies of live rock. A small specimen will eat algae. As it grows older, however, it is not reef compatible, as it will eat soft corals, sponges, tubeworms, clams, starfish, and other invertebrates. It should not be housed with puffers. It is very sensitive to high levels of copper-based medications and will not tolerate high levels of nitrates.

Breeding in an aquarium is extremely difficult with no distinguishing characteristics to help differentiate males from females.

The Red Knob Sea Star is very intolerant of sudden changes in oxygen levels, salinity and pH of the water, and cannot tolerate copper-based medications. The drip acclimation method is highly recommended for all Sea Stars due to their intolerability to changes in water chemistry. It should never be exposed to air while handling.

In the aquarium, the diet can consist of chopped clams, shrimp, fish, and squid fed once a week.

Approximate Purchase Size: Small: 2" to 4" Medium: 4" to 6" Large: 6" to 8"

Customer Testimonials

Paul E Harrisonville , MO
This is a very beautiful starfish. I have had mine for about four months now in a reef tank. He doesn't bother any of the other starfish or invertebrates including carpet anemone. I keep him fed with frozen shrimp, lettuce, and broccoli. He seems to really enjoy it. If you want a very attractive tank, the African Red Knob Sea Star is one you need.
Reese F San Francisco , CA
I recently acquired this to my tank and he is incredible. Most people believe that sea stars just sit around and look cool. His legs move, he climbs the tank, and feeding is awesome. He sticks his arm out of the cage and I place a piece of freeze dried krill on it, using his legs, he brings it down to his mouth and then eats it. I honestly think this is the coolest thing in my tank right now.
Joseph N Elizabeth , NJ
We've had "Koopa" now for 5 years. This starfish has lasted through the very worst our tank had to offer. We had an anemone wipe 90% of the tank out, koopa, the coral banded shrimp and two clownfish were the only survivors. I had him in the sump for a while because he was eating all of my corals, he managed to get himself over the heater, which was in another part of the sump, and had a leg burnt off. I seriously did not think he was going to make it. That was 3 years ago and his 5th leg is almost back to full size. He's awesome to look at, feed plenty of seaweed so he'll stay off your corals.
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