Nenue (Kyphosus vaigiensis) is a herbivorous reef-fish with a long-standing presence in Hawaiian cuisine and Kampachi Farms has been studying its suitability as a potential new species for aquaculture.

The most interesting feature of this species is its unique digestive system that allows them to graze on macroalgae. They subsist on seaweed by using fermentation in the gut to break down the complex carbohydrates of limu. The company performed several rounds of grow-out trials with juveniles that have shown that they can thrive on diets based on aquatic plant material as well as corn and wheat. The company said that herbivory precludes the need for wild-caught forage fish, reducing the overall ecological footprint, and perhaps renders them better suited to small-scale fish farming in less-developed countries. 

Kampachi research also found that adult nenue spawn readily in captivity.  Larvae are exceptionally hardy in preliminary hatchery efforts in an extensive green water culture system. The company is planning larger-scale runs in the near future. Nenue also have ctenoid scales, with a rough texture and row of tiny teeth at the edge. This armor dramatically aids in ectoparasite resistance. Between ready acclimation to captivity, routine marine fish larval rearing, parasite resistance and a broad plant-based diet, this fish has all the trappings of success in sustainable aquaculture, the company stated. 

Kampachi Farms said that seafood sustainability can be improved by diversifying what we eat and prioritizing low-trophic species in this diversification. Legions of researchers are pursuing plant-based and alternative proteins that can suitably nourish those carnivorous fish the market so demands. The more direct way, the simpler way, is to culture natural marine herbivores, the company stated.