Biscuit Starfish: The Charming Cleanup Crew for Your Reef Aquarium

Reef aquariums are beautiful, diverse ecosystems that benefit from a variety of marine life. Among the many fascinating creatures you can introduce to your tank, the biscuit starfish stands out due to its unique shape and essential role in maintaining a clean environment. This comprehensive guide will explore the characteristics of biscuit starfish, their natural habitats, and how to care for them effectively in a reef aquarium.

What Are Biscuit Starfish?

Biscuit starfish, also known as Pentagonaster duebeni or cushion starfish, are echinoderms related to sea stars, sea cucumbers, and sea urchins. They have a distinctive, flattened body shape resembling a biscuit or cushion, typically with a pentagonal form. These starfish are known for their vibrant colours and patterns, making them a visually appealing addition to any aquarium.

Why Keep Biscuit Starfish in a Reef Aquarium?

Biscuit starfish offer several benefits and points of interest in reef aquariums:

1. Detritus Removal: They help keep the tank clean by consuming detritus, algae, and uneaten food.
2. Substrate Aeration: Their movement over the substrate helps to aerate it, promoting a healthier environment for beneficial bacteria.
3. Unique Appearance: Their colourful and unique appearance adds visual interest and beauty to the aquarium.

Setting Up the Ideal Environment

Creating a suitable environment for biscuit starfish is essential for their health and well-being in a reef aquarium. Here are key considerations:

Tank Size and Setup

• Tank Size: A minimum of 30 gallons is recommended to provide ample space and stable water conditions. Larger tanks are preferable for accommodating multiple starfish or larger species.
• Substrate: A sandy or fine gravel substrate is ideal for most starfish species, as it allows for easier movement and feeding.

Water Parameters

• Temperature: Maintain a stable temperature between 72-78°F.
• Salinity: Keep salinity levels between 1.023 and 1.025 specific gravity.
• pH: Ensure the pH is between 8.1 and 8.4.
• Nitrates and Phosphates: Regularly monitor and keep nitrates and phosphates at low levels to ensure optimal water quality.

Lighting

• Moderate lighting is usually sufficient for biscuit starfish. They do not have specific lighting requirements but will benefit from a stable light cycle that supports other tank inhabitants.

Water Movement

• Gentle to moderate water flow is ideal. It should be strong enough to keep detritus in suspension for the starfish to feed on but not so strong that it disrupts their movement.

Feeding Biscuit Starfish

In the wild, biscuit starfish feed on detritus, algae, and small organisms found in the substrate. In a reef aquarium, their diet can be supplemented with:

• Detritus: Ensure that there is a steady supply of detritus and organic matter in the substrate.
• Algae Wafers and Pellets: Provide commercial foods designed for bottom feeders and detritivores.
• Frozen Foods: Supplement their diet with small, finely chopped frozen foods such as mysis shrimp or brine shrimp.

Providing a consistent and appropriate diet is crucial to maintaining the health and activity of biscuit starfish.

Compatibility with Other Tank Inhabitants

When introducing biscuit starfish to a reef tank, consider their compatibility with other tank inhabitants:

Fish

• Safe Choices: Many reef-safe fish, such as clownfish, gobies, and tangs, generally ignore starfish, making them excellent tank mates.

• Potential Issues: Avoid fish species that may disturb or nibble on the starfish, such as certain triggerfish or large wrasses.

Corals and Invertebrates

• Corals: Biscuit starfish are generally safe with most corals. Their feeding activity does not harm corals and can help keep the substrate clean.
• Other Invertebrates: They can coexist with various invertebrates, such as shrimp, crabs, and snails. Monitor interactions to ensure peaceful coexistence.

Behavioural and Ecological Observations

Biscuit starfish exhibit a range of fascinating behaviours that can be observed in a reef tank setting. These behaviours include:

Scavenging and Foraging

• Biscuit starfish move slowly through the substrate, using their tube feet to gather detritus, algae, and other organic matter. This behaviour is both beneficial for the tank’s cleanliness and interesting to watch.

Regeneration

• Like other starfish, biscuit starfish have the remarkable ability to regenerate lost limbs. This ability highlights their resilience and adaptability.

Challenges and Considerations

Keeping biscuit starfish in a reef tank comes with challenges and considerations:

Sensitivity to Water Quality

• Water Quality: Biscuit starfish are sensitive to changes in water quality. Poor water conditions can cause stress and lead to health issues. Regular water changes and monitoring are essential.

Handling with Care

• Delicate Bodies: The bodies of starfish are delicate and can be damaged if handled improperly. Use caution when working in the tank to avoid injury to both yourself and the starfish.

Feeding Requirements

• Consistent Feeding: Providing a steady supply of suitable food is critical for the health of these creatures. Regular feeding with appropriate supplements is necessary to maintain their nutritional needs.

Types of Biscuit Starfish and Colour Descriptions

1. Red Biscuit Starfish (Pentagonaster duebeni)
• Colour: Bright red with a pentagonal shape.
• Size: Up to 6 inches.

2. Blue Biscuit Starfish (Pentagonaster pulchellus)
• Colour: Vivid blue with white or darker blue spots.
• Size: Up to 6 inches.

3. Yellow Biscuit Starfish (Pentagonaster aurantiacus)
• Colour: Bright yellow with a pentagonal shape.
• Size: Up to 6 inches.

4. Orange Biscuit Starfish (Pentagonaster albidus)
• Colour: Deep orange with white spots.
• Size: Up to 6 inches.

5. Green Biscuit Starfish (Pentagonaster viridis)
• Colour: Green with darker green or brown spots.
• Size: Up to 6 inches.

Selecting the Right Biscuit Starfish

When choosing biscuit starfish for your reef tank, consider the following factors:

Appearance

• Look for starfish with healthy, intact bodies and no signs of damage or stress. Healthy starfish will actively move and respond to stimuli.

Source

• Purchase biscuit starfish from reputable sources that provide healthy, well-maintained specimens. Avoid starfish that show signs of illness or poor health.

Tank Conditions

• Ensure that your tank conditions are stable and suitable for starfish before introducing them. This includes maintaining optimal water parameters and providing ample substrate for their feeding and movement.

Conclusion

Biscuit starfish are a valuable addition to any reef aquarium, offering both aesthetic appeal and functional benefits. By understanding their natural habitat and providing a suitable environment, aquarists can enjoy the dynamic presence of these charming cleanup crews.

Ensuring proper tank setup, compatible tank mates, and adequate nutrition will help biscuit starfish thrive, contributing to a pristine and healthy reef tank. Whether you’re a seasoned aquarist or new to the hobby, biscuit starfish can bring a touch of the wild, natural world into your home aquarium, offering endless opportunities for observation and appreciation.