Training a little fish named Kujo…

At the Waikiki Aquarium I was hired on by the Disease and Quarantine Specialist, my background was and still is anchored in the world of fishes. Under my former boss Wendy Lee, I learned how to give seahorses injections, how to care for some of the rarest specimens in the world like the peppermint angelfish (Centropyge boylei), and countless other medications and procedures which have been journalized for personal reference. While I find many of these topics fascinating and the chance to remove a large tumor on a gill mass can be the highlight of my day, I’ve found many do not share my enthrallment with the world of fish disease, as such sharing a bit about my other projects seemed a better use of a blog entry.

When the words “aquarium” and “animal training” appear in a sentence, images of dolphins, seals, and other marine mammals doing tricks with a wetsuit clad trainer may spring to mind. While the world of marine mammal training may seem like a dream job to some, others whom also work at aquariums tend to pursue other routes which can at times lead them to dip their toes in the world of animal training albeit with slightly different subjects.

I met Kujo on my first day of work in January of 2012, he (we call him a male although I have not actually established a sex) was instantly my favorite fish. His species name is Oplegnathus punctatus also known as the Spotted Knife Jaw. While the nickname and common name might lead one to believe this is a particularly vicious animal I had him eating out of my hand by my second day on the job. His training began with this same hand feeding method although it was rather informal when compared to most animal training regiments.

To start training this little fish, I would simply slap the water before feeding. A predator of invertebrates Kujo’s diet at the aquarium is comprised largely of fresh shrimp, pieces of squid, and the aquariums own gelatin based food which is designed to provide nutrients such as algae derivatives and certain proteins that captive animals may be deficient in. Being the sole animal in a twenty foot tank of water the queue provided by my slapping the water was easily noticeable. Kujo’s response was initially to investigate the noise, and when the connection was made between feeding time following the hand slap signal Kujo’s response speed was greatly increased.

After several months my boss at the time thought it might be best to train Kujo to target. The act of targeting means a subject (in this case Kujo) is presented with an object (we use a yellow and pink hula hoop with Hello Kitty duct tape on it) the subject then moves to the point the object is place and stations. The act of stationing for Kujo consists of waiting in the center of the hula hoop until he is either rewarded or another behavior is requested. A reward consists of food, and the theory behind training Kujo to station is based on the aquarium’s future plans for him.

Spotted Knifejaw’s grow quite large, some upwards of twenty six inches, as such Kujo is destined for the aquarium’s shark tank. The problem Kujo will face in such a large tank is that he is a slower moving predator, while this does not immediately appear as a problem, his tank mates are largely comprised of very fast swimming fishes like jacks (family Carangidae) and some sharks. These other fishes, especially in a captive setting can out compete the slower moving Kujo for food at feeding times.

The ability Kujo has to station will allow him to be hand fed at any location in the tank. When food is thrown in the water to feed the other fishes, Kujo’s hula hoop will be placed in a readily accessible point of the tank for both trainer and fish, thus allowing his trainer to feed Kujo directly and ensuring he is fed appropriately in order to guarantee his continued health.

While Kujo has mastered the act of stationing I thought an enrichment opportunity may also be present in furthering his training. Enrichment for a captive animal includes pretty much anything that can be seen as mentally or physically stimulating. Kujo is kept in a large, but mostly empty tank providing ample swimming room, but lacking the ability to pick at rocks or chase food items. Simply figuring out how to catch a live shrimp for many animals is a mentally stimulating act, as Kujo does not have such opportunities when I have the time I train new behaviors.

This fish’s latest behavior is swimming through his hula hoop. I began training with a method known as “baiting”. The process was fairly simple. I would ask Kujo to station by placing his hula hoop on the surface of the water. Once he was in position waiting to be fed I would place the hula hoop underwater to create a vertical circle for him to swim through. I would hold food on one end of the hoop until he swam through. If he swam through the hoop he would be rewarded with food.

Once the idea of swimming through the hoop had sunk in, I stopped baiting the behavior meaning I eliminated the visible reward. When the hoop was again placed in the water I provided Kujo a new target to swim towards, in this case my open hand. While there was no food in it I used my hand to indicate which side of the hoop I wanted him to swim towards, after he performed the correct swim I removed both my hoop and hand from the water and rewarded him with food.

Now that Kujo is trained to swim through a hula hoop I’m working on further behaviors simply for the sake of enrichment. They include swimming multiple times through the hoop before being rewarded, swimming in a circle, and swimming in a zig-zag pattern.

While he is not yet on exhibit a behind the scenes tour of the Waikiki Aquarium may provide you with a sneak peak of this fun little fish. Stay tuned to Aquarium news as a series of fish training videos may be available in the future if permissions are granted.

-Billy Roehl


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This entry was posted on Friday, February 8th, 2013 at 12:28 am and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.