- One juvenile Saddleback butterflyfish (Chaetodon ephippium) was raised from wild eggs.
- The larval duration was about 68 days.
- First culture record of Chaetodon ephippium.
Butterflyfish are mostly small, conspicuously colorful reef fish with deep, laterally compressed bodies and small mouths. The family comprises 130 species in 11 genera. Their primary diet consists of benthic invertebrates, especially coral polyps. Their vibrant colors make them very popular among marine aquarists; however, many species have specialized diets, such as stony coral polyps, and struggle to thrive in captivity, refusing to feed. Interestingly, wild-collected, late-stage larvae of some of these species can be conditioned onto aquarium foods. Bottlenecks in spawning adults and larval rearing continue to keep butterflyfish from being commercially aquacultured. The Chaetodon genus is the largest among the Chaetodontidae, with about 90 described species.
The Saddleback butterflyfish (Chaetodon ephippium) inhabits healthy coral reefs in the Indian and Pacific Oceans. Boasting a unique combination of size (nearly 12 inches), striking morphology, diverse diet, and fascinating social behavior, it’s no wonder this species is a favorite among marine enthusiasts. Its most recognizable feature is the namesake “saddle” – a broad, black band extending across the posterior portion of its body, contrasting sharply against the silvery-white background and vibrant orange dorsal fin. The lower body is adorned with bright blue horizontal stripes, adding a touch of personality to its overall elegance.
C. ephippium exhibit a diverse social behavior, encountered solitarily, in pairs, or even in small groups. Adults form monogamous pairs during breeding season, while juveniles often are solitary, cryptic, and inshore. These inquisitive fish are omnivores, feeding on a varied diet that includes filamentous algae, small invertebrates like sponges and tunicates, coral polyps, and fish eggs. Their elongated snouts and bristle-like teeth are perfectly adapted for picking food from crevices and coral branches. C. ephippium contribute to the coral reef ecosystem. Their consumption of algae helps control its growth and maintain the delicate balance of the reef. Additionally, some individuals have been observed acting as “cleaners,” picking off parasites and dead skin from other fish species.
Culture and Development
One C. ephippium juvenile was raised from a mix of wild eggs collected off Oahu’s south shore in August 2023. The fish was raised together with other species in a static 50L tank system on cultured copepods and artemia. Isochrysis, tetraselmis, and pavlova were used to enrich the nutritional content of the live foods. Larvae were transferred to a new tank when rearing conditions deteriorated (ammonia became elevated). The juvenile was grown out only on artemia under low light in an 80L tank with sand bottom attached to a recirculation system.
The C. ephippium larva was first identified in the mix of larval species on 24 days post-hatch (dph), during a tank transfer. It measured about 5.5 mm total length (TL) and had just completed flexion. It had a small mouth, large eyes, and a triangular-shaped yellow body, covered in fine black dots. Small bony plates on the head and the posteriorly-directed flat preopercle spine were already prominent.
By 36 dph, the larval fish had grown to 9 mm TL. The head was more rounded, and the body was wider. The black dots became more dense and body had a reflective golden appearance. The bony plates and flat preopercle spine now covered much of the head and extended past mid-body. The rays on the fins were visible, with the pectoral and pelvic fins appearing fully formed. The eyes were large, and the mouth remained small. The larva had become very active, swimming rapidly around the tank while feeding.
Over the next 23 days, the fish added an impressive 9 mm in total length. By 59 days old, now measuring 18 mm, the larva had a rounded head and a golden oval body. The dark head bar and vibrantly colored pelvic fins, characteristic of juveniles, signaled that settlement was close. Despite this imminent shift, the larva’s high activity level persisted.
The following 9 days brought a burst of color rather than significant growth. The swimming motion changed from erratic darting to a calm and steady glide, further indicating imminent settlement. On 68 dph, the juvenile fish (see header image) was transferred to a grow-out system, where it thrived for two months together with juvenile wrasses and gobies. It now resides at the Waikiki Aquarium.
C. ephippium represents the fourth butterflyfish raised for the project thus far, after Heniochus diphreutes, C. kleinii, and C. auriga. Culturing this fish was exciting. First, it stands out as the most vibrant butterflyfish species among the four involved in the project. Second, it exhibited a higher survival rate and shorter larval duration than the other three species, suggesting the larvae may be more suitable for aquaculture and/or benefited from an improved culture technique. Interestingly, while larval morphology of C. ephippium closely resembled that of C. auriga, the larvae appear easier to culture. These observation provides valuable insights into the unique characteristics that contribute to larval success in captivity and paves the way for further research and optimization of rearing protocols for this captivating species.
Further Butterflyfish Aquaculture Research
- Forcipiger flavissimus, Longnose butterflyfish (Oceanic Institute/Rising Tide Conservation)
- Chelmon rostratus, Copperband Butterflyfish (UF/IFAS IRREC)
- Chaetodon milliaris, Milletseed or Lemon butterflyfish (Oceanic Institute/Rising Tide Conservation)
- Chaetodon sedentarius, Reef butterflyfish (University of Florida/Rising Tide Conservation)
- Chaetodon striatus, Banded butterflyfish (University of Florida/Rising Tide Conservation)
- Parachaetodon ocellatus, Kite butterflyfish (Thailand’s Samutsakorn Costal Fisheries Research and Development Center)
Baensch, F. 2016. The Long Road to Breeding Butterflyfishes. CORAL 13 (3): 46–59. PDF available upon request.
Randall, John E., 2007. Reef and Shore Fishes of the Hawaiian Islands. Sea Grant College Program, University of Hawai’i, Honolulu. i-xivb + 1-546.
Pratchett, M. S., Berumen, M. L. & Kapoor, B. G. (2014). Biology of Butterflyfishes. CRC Press, Boca Raton.