More info
Datasheet
| Minimum Tank Size | 400 litres / 105.67 US gallons |
| Maximum Size | 30.0cm / 11.81inches |
| Reef Compatible | Often reef safe |
| Temperament | Peaceful |
| Temperature | 22.2°C / 71.96°F - 25.6°C / 78.08°F |
| Specific Gravity | 1.020-1.025 |
| Carbonate Hardness | 8-12 |
| pH | 8.1-8.4 |
General Description
The Pencil urchin, scientifically known as Heterocentrotus mammillatus, belongs to the Echinoidea family. These sea creatures are effective algae eaters, consuming a variety of algae such as coralline algae and green hair algae. They are nocturnal creatures and are most active when the lighting is dimmed or turned off. Pencil urchins are generally peaceful and require good hiding spots, usually found between live rocks.
Aquarium Suitability
The Pencil urchin is suitable for most aquarium setups, with average hardiness levels. They require a minimum tank size of 400 liters, along with a stable environment to thrive. It is essential to acclimatize them slowly to changes in salinity. This species is often compatible with reef environments but should not be kept in tanks with minimal algae, as they heavily rely on it for food.
Demands, Care and Hardiness
This species has a peaceful temperament and thrives in water conditions with a pH range of 8.1-8.4, a specific gravity of 1.020-1.025, and a temperature between 22.2-25.6°C. Pencil urchins prefer a diet rich in macroalgae like seaweed or nori, microalgae such as spirulina, other invertebrates, and small crustaceans like krill and mysis.
Reef Suitability
Pencil urchins are often considered reef-safe, making them a compatible addition to reef aquariums. Their algae-eating habits can help maintain a balanced ecosystem within the reef tank.
Aquarium Setup
When setting up an aquarium for Pencil urchins, it is crucial to provide them with ample hiding places, especially among live rocks. Maintaining a well-established tank with sufficient algae growth is essential for their dietary needs. Ensuring water parameters are within the specified range and offering a varied diet will contribute to their overall well-being.
Behaviour
Being nocturnal, Pencil urchins are most active during the night or when the aquarium lights are dimmed. They tend to roam around the tank, grazing on algae and searching for food.
Feeding and Diet
Pencil urchins primarily feed on various types of algae, including macroalgae and microalgae. Supplementing their diet with other invertebrates and small crustaceans ensures they receive a balanced nutritional intake.
Dimorphism
Dimorphism in Pencil urchins refers to the differences in physical characteristics between males and females. In captivity, these creatures have been known to reproduce, adding to the biodiversity of the aquarium environment.
Habitat and Distribution
The Pencil urchin, native to the East Indian Ocean, inhabits rocky areas and coral reefs. They play a vital role in reef ecosystems by controlling algae growth and contributing to the overall balance of marine environments.