Common name: Comet

General Information

The Comet, scientifically known as Calloplesiops altivelis, is a stunning and enigmatic fish that has captivated aquarium enthusiasts for decades. Its elongated body, adorned with a mesmerizing pattern of white spots against a deep brown to black background, gives it a celestial appearance, earning it the nickname "Marine Betta." Despite its name, it is not related to freshwater bettas (Betta splendens). This species is native to the Indo-Pacific region, where it inhabits coral reefs and rocky crevices.

The Comet is a nocturnal species, often hiding during the day and emerging at night to hunt. Its unique behavior and striking appearance make it a prized addition to marine aquariums, particularly for those who appreciate its reclusive yet graceful nature. However, its shy demeanor and specific care requirements make it more suitable for intermediate to advanced hobbyists.

Care

Comets thrive in aquariums that mimic their natural reef environment. They prefer tanks with plenty of live rock, caves, and overhangs to provide hiding spots. These features help them feel secure and reduce stress. While they are hardy once acclimated, they require stable water conditions and a peaceful tank environment to truly thrive.

This species is best suited for tanks of at least 200 liters (50 gallons) to accommodate its adult size and provide ample swimming space. A dimly lit tank or areas with subdued lighting will help replicate its natural habitat and encourage more natural behavior.

Diet and Feeding

In the wild, Comets are carnivorous, preying on small fish, crustaceans, and other invertebrates. In captivity, they can be fed a diet of high-quality frozen or live foods, such as mysis shrimp, brine shrimp, and finely chopped seafood. They may also accept enriched pellets or flakes over time, but these should not be the primary diet.

Feed them once or twice daily, offering only as much food as they can consume within a few minutes. Comets are ambush predators, so they may take their time to approach and consume food. Patience is key when feeding this species.

Behavior and Compatibility

Comets are generally peaceful but can be territorial, especially towards conspecifics or similarly shaped fish. They are best kept singly unless housed in a very large tank with ample hiding spots to reduce territorial disputes. Their shy nature makes them compatible with other peaceful tank mates, but they may prey on very small fish or invertebrates, so caution is advised when selecting tank companions.

This species is reef-safe with caution, as it may eat small ornamental shrimp or other tiny invertebrates. However, it poses no threat to corals or larger invertebrates, making it a suitable choice for many reef tanks.

Reproduction

Breeding Comets in captivity is rare but not impossible. They are egg-layers, with the male guarding the eggs until they hatch. Successful breeding requires a well-established tank, stable water conditions, and a compatible pair. Raising the fry is challenging, as they require very small live foods, such as rotifers, during their early stages.

Health and Common Issues

Comets are hardy once acclimated but can be sensitive to poor water quality and sudden changes in tank conditions. Regular water changes, stable parameters, and a varied diet are essential for their health. They are susceptible to common marine diseases, such as ich and velvet, so quarantine new additions and monitor for signs of illness.

When selecting a Comet, look for active individuals with vibrant coloration and no visible signs of disease. Avoid fish that appear lethargic or have damaged fins, as these may indicate underlying health issues.

Habitat

The Comet is native to the Indo-Pacific region, including areas such as the Red Sea, East Africa, Indonesia, and the Philippines. It is typically found in coral-rich lagoons and outer reef slopes at depths ranging from 3 to 40 meters (10 to 130 feet). These environments provide ample hiding spots and a diverse range of prey, which are essential for their survival.

In captivity, replicating these conditions with live rock, caves, and a dimly lit environment will help ensure their well-being.