The Chocolate Chip Starfish (Protoreaster nodosus) is a marine invertebrate found in the Indo-Pacific. It is recognized by distinctive, horn-shaped protrusions on its upper surface, resembling chocolate chips. The starfish can display colors like white, yellow, brown, red, blue, or light tan. Its unique appearance makes it a captivating addition to many aquariums.
Diet of the Chocolate Chip Starfish
Chocolate Chip Starfish are omnivores and opportunistic scavengers, primarily feeding on detritus, decaying organic matter, and biofilm in their natural habitats. In the wild, they consume tiny benthic invertebrates. They also practice suspension-feeding, capturing and ingesting food particles like phytoplankton, zooplankton, and algae films from the water column.
These starfish employ a unique feeding mechanism: they evert, or push out, their stomach through their mouth and onto their prey. Digestive enzymes are then released to break down the food externally, turning it into a liquid. Once liquefied, the stomach absorbs nutrients and retracts. While not their primary food source, Chocolate Chip Starfish are predatory and will consume soft corals, sponges, tubeworms, clams, and even other smaller starfish. This opportunistic behavior can lead to them grazing on corals or polyps in an aquarium if natural food sources are scarce.
Keeping Chocolate Chip Starfish in Aquariums
Chocolate Chip Starfish are not suitable for reef aquariums due to their predatory and opportunistic feeding habits. They may actively seek out and consume corals, sponges, and other sessile invertebrates. Their large size, potentially reaching up to 15 inches in diameter, also means their movement and weight can physically damage delicate corals.
These starfish are better suited for Fish Only With Live Rock (FOWLR) aquariums, where the risk to corals and other invertebrates is eliminated. Supplemental feeding is necessary to ensure they receive adequate nutrition. They can be fed sinking pellets, algae wafers, and meaty foods such as chopped shrimp, squid, or clams. Spot-feeding them by placing food directly near their mouth with tongs helps prevent other tank inhabitants from consuming it.
Maintaining stable water parameters, including a pH between 8.1 and 8.4, and a specific gravity between 1.021 and 1.025, is important for their well-being. They also require a sandy substrate several inches deep, mimicking their natural habitat.