Synopsis
- Mahi Mahi (Coryphaena hippurus) larvae were raised from wild-spawned eggs at 77-79F on wild copepods.
- The larval duration was 30 days.
Background
Dolphinfishes are large, epipelagic, predatory fishes that primarily occur in tropical and sub-tropical seas worldwide. The family presently only comprises two species, the common Dolphinfish or Mahi Mahi (Coryphaena hippurus) and the Pompano Dolphin (C. equiselis). Dolphinfishes are among the fastest growing fishes in the ocean and serve as a primary food source for many pelagic predators. Juveniles and adults occur mostly near the surface where they often associate with floating debris, particularly Sargassum seaweed. The larvae are often found in deeper water up to 600 feet. Dolphinfishes are delicious to eat and are an important part of recreational and commercial fisheries. Their high demand, fast growth rate, good food conversion efficiency, high fecundity and short larval phase make them excellent candidates for aquaculture.
Culture and Development of Eggs and Larvae
Mahi Mahi (Coryphaena hippurus) larvae were reared on multiple occasions in the winter-spring of 2012-1014 from wild collected eggs (1.3 mm in diameter). C. hippurus larvae have unpigmented eyes and an unformed mouth at hatching, yet are relatively large, at 3.5 mm TL. First feeding larvae (3 dph, 5 mm TL) prey on large copepod nauplii and copepodites (70-100 um) in the rearing tank. Development is rapid with larvae undergoing flexion as early as 10 dph (8 mm TL). Juvenile C. hippurus transformation is complete near 20 dph (20 mm TL). C. hippurus larvae are heavily pigmented (yellow-brown) at all stages, except for the caudal peduncle and its finfold in the early preflexion stage.
Conclusion
C. hippurus larvae are easy to raise (experienced 0% larval mortality in all trials) and require no special conditions through transformation. The larvae readily feed on copepods throughout the rearing phase, unlike other epipelagic species such as tuna larvae, that prey exclusively on larval fish during later stages. Later stage C. hippurus will also feed on artemia but grow noticeable slower than when raised on a copepod-only diet. Juvenile C. hippurus start to accept frozen foods at about 25 mm TL and can even be hand fed. Like adult C. hippurus, juveniles develop beautiful iridescent color patterns that change depending on their stress level. This is the fastest growing fish species cultured for the project to date.