Marine Betta - Calloplesiops altivelis

Marine Bettas (Calloplesiops altivelis) are also known as "Comets". They have black bodies and elongated fins covered with white or light blue spots. They also have a large false eye spot on the rear of the dorsal fin.

The family Plesiopsidae gives us the Longfins, Roundhead, and Spiny Basslets - fish related to groupers but with a different appearance and temperament than many others seen within the hobby. In general, fish of this family are rock-dwellers. You are far more likely to find them under a rocky overhang or perching in a cave than in the open water and some fish like the Assessors even hang out upside-down most of the time. Longfins have long pectoral fins that they perch on like legs while they survey their surroundings.

These fish are ambush predators, meaning they wait for their food to come to them before striking prey with lightning speed. They are generally peaceful towards fish and inverts too large for them to eat. Their coloration is usually subdued; most are dusky or dark colored with a few, subtle, colorful embellishments. The size range of these fish ranges as well, from the small Assessors to the moderately-sized Marine Bettas and Roundhead Groupers.

These fish can be fed a varied meaty diet. Some may require live foods at first to trigger a feeding response but may be weaned onto frozen, fresh or prepared foods in time. Take care that all tankmates are getting fed, as more reclusive groupers may be outcompeted by more aggressive feeders, and some more aggressive groupers may eat more than their share and not allow other tankmates to feed. These fish should not be kept with very small fish or with crustaceans like crabs and shrimp.

Visit That Fish Blog for more information from our marine biologists on Longfins and Devilfish and other aquarium-related topics!