Butterfly fish are a captivating group of fish, found in both freshwater and marine environments. While sharing a common name, these fish are not necessarily closely related, exhibiting unique adaptations to their respective habitats and diets. This article explores the dietary habits and feeding behaviors of two distinct types of butterfly fish: the African butterfly fish (Pantodon buchholzi) and reef butterfly fish (Chaetodontidae family).
African Butterfly Fish: An Insectivore of the Freshwater Realm
The African butterfly fish, scientifically known as Pantodon buchholzi, is a unique freshwater species native to the slow-moving streams, lakes, and swamps of West Africa, including Sierra Leone, the Republic of Congo, Chad, and Niger. Often found just below the water's surface, these fish have developed specialized hunting techniques and physical characteristics suited to their environment.
Physical Characteristics and Hunting Strategy
African butterfly fish are relatively small, reaching about 5 inches (12.7 cm) when fully grown. They exhibit a clever camouflage pattern with a black and brown body and a lighter underbelly, allowing them to blend seamlessly with the murky waters and evade predators. Their most distinctive feature is their butterfly-like pectoral fins, which fan out from their body, enabling them to suspend motionlessly in the water, resembling floating plants or foliage. Their ventral fins are thread-like, likely providing further stabilization and aiding in detecting vibrations in the water.
These fish are ambush predators, patiently waiting for the opportune moment to strike their prey. Their large, upward-pointing mouths are perfectly adapted for capturing insects and small prey that touch the water's surface, similar to the arowana.
Dietary Preferences and Feeding Behavior
African butterfly fish are primarily insectivores, meaning that insects form the bulk of their diet. In their natural habitat, they feed on various insects that fall onto the water's surface. In captivity, they readily accept live and frozen foods such as brine shrimp and bloodworms. It is crucial to remember that these fish feed on the surface and will not venture to the bottom of the tank for food.
Read also: Caring for the African Butterfly Fish
If an African butterfly fish appears distressed and swims more in the upper and middle water column, it may be searching for food. Maintaining a consistent and appropriate diet is essential for their well-being.
Tank Mates and Temperament
African butterfly fish are generally peaceful and can be kept with other fish if the conditions are right. However, they may eat smaller fish, such as guppies, that swim near the surface. Within their own species, males may exhibit territorial behavior during spawning periods, but these displays rarely result in serious injury.
Breeding
Breeding African butterfly fish can be a rewarding experience for dedicated aquarists. They are egg-scatterers, and it is recommended to move them to a separate breeding tank with ample floating plants and surface area. To initiate spawning, the water level should be lowered to a few inches for a couple of weeks while providing high-quality food. If successful, the fish will spawn for several days, depositing up to 100 eggs per day. These eggs float to the surface and should be transferred to another tank with similar water parameters to prevent the parents from consuming them.
Raising the fry, however, can be challenging, as they are not efficient hunters and require very small live food, such as newly hatched brine shrimp. They also demand stable water parameters and frequent, small water changes.
Reef Butterfly Fish: Coral Reef Inhabitants with Specialized Snouts
Reef butterfly fish belong to the Chaetodontidae family and are found on coral reefs worldwide. These brightly colored fish have adapted to thrive in the complex and diverse reef environment.
Read also: Incorporating Fish into a Carnivore Meal Plan
Physical Characteristics and Habitat
Butterflyfish are fairly small and laterally flattened, resembling a disc with rounded fins. They are brightly colored, often with some combination of yellow, black, and white. Their flattened bodies and strong pectoral fins enable them to maneuver precisely within the intricate coral structures.
Dietary Preferences and Feeding Behavior
Reef butterfly fish exhibit diverse feeding habits, with some species specializing in particular food sources. Some butterflyfish take advantage of energy-rich coral mucus as a primary food source. Corals produce mucus as a protective layer or use its stickiness to trap food. Butterflyfish feed on this nutrient-rich layer and take advantage of this easy to consume food source.
Many butterflyfish species have evolved specialized snouts and mouths to access food hidden within the reef. The longnose butterflyfish (Forcipiger spp.) has an elongated snout that allows it to probe deep into the reef to reach prey inaccessible to other fish. Other species, like the banded butterflyfish (Chaetodon striatus), have shorter snouts that enable them to consume a wider variety of prey, including worms, corals, and small crustaceans.
Within their narrow jaws, most butterflyfish have rows of short, bristle-like teeth that allow them to firmly grip their prey as they extract it from its refuge.
Foraging Strategies and Energy Expenditure
Feeding on small prey requires butterflyfish to spend a significant amount of time foraging. As diurnal animals, they gather their food during the 12 hours of the tropical day. Hunger may sometimes drive them to continue feeding at night, especially around the time of the full moon, although this increases their risk of encountering predators.
Read also: Choosing Fish on Keto
Studies on feeding rates in the Red Sea have shown that butterflyfish expend considerable energy in their foraging efforts. Some species may bite at the surface of the coral, on average, every five seconds throughout the day.
Ecological Role
Predation by butterflyfish plays a crucial role in maintaining the diversity of coral reef communities. By feeding on sessile invertebrates such as sponges and corals, they prevent certain species from dominating the reef and outcompeting others. For example, predation by angelfish on certain sponges and sea squirts is known to boost the populations of poorer competitors, such as bryozoans.
Mating Behavior and Early Life
Butterflyfish often form long-lasting pair bonds and exhibit monogamous behavior. They spawn at dusk, rising several to many meters in the water column. The male follows the female, fertilizing the eggs as they are released. The eggs are spherical and slightly transparent, hatching in about a day and a half. The larvae are planktonic for an extended period, possibly at least 40 days, before settling on the reef at night and quickly transforming into juveniles.
The larvae of butterflyfish are unique, with their heads encased in bony armor and large bony plates extending backward from the head. During the planktonic stage, they are tiny, growing from about 1 mm to 5 mm over several weeks. Often the juveniles have different colors and patterns than the adults.
Reef Butterflyfish (Chaetodon sedentarius)
The reef butterflyfish (Chaetodon sedentarius) is a rectangular-shaped species found in the Western Atlantic. It has a black bar down its face and another down the posterior of its body and fins, with yellow on its fins and a yellow tail. It lives around coral reefs and is ideally shaped to poke into crevasses for invertebrates to eat.
This species is well-suited to life on the reef, with its compressed body allowing it to dart in and out of coral. The small, protractile mouth is specifically adapted to crevice feeding. The teeth are long and slender, flattened, and slightly curved at the tips, designed for scraping and nipping at the small invertebrates, including polychaete worms, shrimps, and amphipods, that make up its diet.
Adult reef butterflyfish are often found in pairs, suggesting monogamy and pair fidelity. They spawn at dusk during a long, vigorous courtship. The pair circle each other, each fish head to tail until one fish breaks and darts off with the other close behind. The pair then swim upward and release the eggs and sperm. The female releases from three to four thousand eggs during the spawning event. The eggs are small, transparent and pelagic, and hatch within a day into minute, translucent silvery-grey larvae.
The larvae of reef butterflyfish have a head encased in bony armor and large bony plates extending backwards from the head. These larvae, called âtholichthys,â grow to about 20mm, after which they settle on the bottom during the night. By dawn, they have already transformed into the juvenile stage of their life. Their color now closely matches the color of the adult. Those larvae that escape from predators and survive the transformation will hide in crevices until they are big enough to be relatively safe.
Predators of the reef butterflyfish include larger reef fish like moray eels, snappers, and groupers. If threatened, the butterfly generally tries to swim away and hide, but if for some reason it canât flee it often takes up a defensive posture.