Protoreaster linckii

(Blainville, 1834)

Red-knobbed Star

Range: Indo-West Pacific Ocean

Size: 12 inches (30 cm)

Natural Environment: Inhabits shallow sandy and muddy bottoms and seagrass beds in lagoons and back reef areas where it feeds upon sponges and other benthic invertebrate.

General Husbandry: Common in the home aquarium trade because it's plentiful and easy to catch in the wild.

Not suited for reef aquariums, as it will consumed anemones, gorgonians, soft corals, stony coral polyps, sponges, clams, urchins, tubeworms, and small sleeping fish.

Because of its physical shape, i.e., wide arms and thick spiny body, it is incapable of searching for food in-between rockwork in most aquaria. In captivity, therefore, it requires a more open environment that is easily navigated.

As for feeding, there probably isn't a hobbyist aquarium that can naturally provide this creature its necessary nutritional needs long term. I suggest placing different type and size organic foodstuffs on the aquarium substrate just prior to the lights going out. These creatures, if healthy, are very capable of knowing when food enters the aquarium and will quickly take the shortest path to the foodstuff. Long-term success rate with this sea star appears to be poor, as most die of malnutrition.

Taxonomy:

Kingdom: Animalia

Phylum: Echinodermata

Class: Asteroidea

Order: Valvatida

Family: Oreasteridae

Genus: Protoreaster

FYI: Vulnerable to sudden salinity/specific gravity changes.

Experience Level: Intermediate

Diet: Carnivore

Aquarium Environment: Fish-only aquarium

Coral Safe: No

Fish Safe: With caution

Invertebrate Safe: No

Acclimation Time: Sensitive to specific gravity/salinity changes, therefore be sure to adjust the bag's water to that of the aquarium in which it will be placed by slowly adding small amounts of aquarium water to the bag every few minutes. In most cases, this process should take at least 15 minutes.

Aquarium Hardiness: Moderately difficult

Temperature Range: 72 - 83°F (22 - 28°C)

Minimum Tank Size: 100 gallons

Specific Gravity: 1.023 - 1.025

pH: 8.0 - 8.4