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Yellow Tang: The First of Many

    By Tyler Moss. December 5, 2015 - 7:31 pm

yellow_tangYellow tang are popular in the aquarium trade and nearly all of them sold in pet shops are harvested off the shores of the Hawaiian Islands. Between 2005 and 2009, over 1.5 million yellow tangs were harvested off of Hawaii, which has an estimated wholesale value of $5 million.

Oceanic Institute (OI) wants to provide an alternative source for the aquarium trade. By aquaculturing yellow tangs, the price for the fish in aquariums can go down and a potential threat to the ecosystem can be avoided. The person behind the research and success is Dr. Chad Callan.

Dr. Callan, who is Director of the Finfish Department at OI and an affiliate faculty member at HPU, along with his team of graduate students, were able to successfully mate yellow tang. Other organizations have tried to breed yellow tang but were only successful in obtaining fertilized eggs and larval stages.

Dr. Callan and his team, however, were able to grow the fish past the larval stage and into their juvenile stage (when the tangs begin to start taking a fish-like shape, turning yellow, and settling into deeper parts of the tank).

“It takes about 55 days for fertilized eggs to become yellow juvenile fish,” says Dean Kline. For 15 years, researchers at OI developed technology to successfully grow the yellow tang past the larval stage.

One of their biggest challenges was to have a food source for the fish. I was able to talk to an OI employee, Dean Kline, who grew the food source for the yellow tang and took part in growth and development of the fish. He was glad to help spread the good news and the success that OI was able to achieve.

He told me that “OI grew every part of the food chain” for the yellow tang, which took a lot of work. They first cultivated algae, or phytoplankton, which were fed to copepods, which are a type of zooplankton, and the copepods were then fed to the fish.

He also told me that the copepods were collected from Kaneohe Bay and are a local species. Growing the food source for the yellow tangs required two main steps: finding them a food source and mass producing it. After they completed these two hard steps, they were able to grow their fish.

OI now has about 200 juvenile yellow tang. Their next steps include “optimizing conditions to increase survival,” donating some, selling some to produce revenue so they can continue with their expensive research, and keep some for brudestock (reproducing adults) to repeat the cycle.

OI is also interested in applying similar methods used on the yellow tang to aquaculture other types of surgeon fish. By reapplying these technologies to other surgeon fish, they can hopefully negate the dependency on wild caught aquarium fish and create potential jobs in the marine biology field.

Photo courtesy of en.wikipedia.org.