Were I back in Alabama right now, I would be enjoying yards of swimming, hours of pedaling and miles of running the streets and trails. My friends, who share this form of play with me, and I do this not only for sheer fun of physical exertion, but to train for a running race or a triathlon. While my buddies are off at the races I continue training. Currently, I am concentrating on fish training. No, this is not some new diving technique. I am training fish for use in laboratory experiments.
Last week our project sponsored the Palmer Station Fishing Derby. The goal was to help us catch a good number of a common fish that we would maintain for use in feeding experiments these last few weeks on station. The angler bringing in the most fish during the 3-day tournament would win the grand prize of a brand new bass boat (yes, that is a whopper of a fish tale!). Just about everybody on station tried their luck dangling a hook and line in the waters surrounding the station in hopes of a nibble or two. Dan (“the Man”) found a rich hole pole-ing up 14 keepers during the tourney. Due to his project association, he was ineligible for any of the exciting prizes and awards. Marge, the station cook, reeled in a record 9 fish, as well as the coveted title of Palmer Station Fisherwoman of the 2004 Winter and a prize of her choice. (She declined the bass boat.) Bravo Marge!
While the casting competition was in full fling, special tanks called the cascade tanks, in the Aquarium Building were being prepared for our new finned residents. This set of 4 rectangular tanks is double-deckered. Seawater flows into the two top tanks and then cascades down through tubing into the pair of bottom tanks. Each tank is divided into 3 compartments with custom-made pvc-frames to which window screening was cabled-tied. Each of the 12 chosen, lucky fish would have their own room. Marge’s last caught fish is in Room # 12. She named him Otis.
Otis is a bottom dwelling fish known scientifically as Notothenia coriiceps and commonly called the black rockcod. Their color patterns are highly variable though with black as well as brown and gray splotches on their back and sides and mustard-yellow tinted fins. These color patterns are an identification bonus for us when one Houdini-like squeezes their broad head and 30 cm (~1 ft) long scaly body through the dividers to visit the next door neighbor. Otis has so far been content to be a home body.
These fish will further our study of defensive chemical compounds that animals like sponges and tunicates may produce. (See Jim’s previous entries). Like the seastars we maintain in a nearby tank, the fish will be taste testers. We will offer the fish specially prepared disks of food and record whether or not the fish eats it. Some of the disks will be treated with extracts derived from a sponge or tunicate of interest. It is sort of like flavoring baked goodies with vanilla or almond extract (chemically derived from the bean or nut) only probably not as good on our taste buds. So we will let the fish guide us to which of the extracts are not palatable or tasty.
But before we get to that crucial part of the experiment, the fish need to be tolerant of their new temporary room, and tolerant of being hand fed. This is where the training comes in. Several times a day, I work with the fish doing the same thing each time. I am training them to recognize them that food is delivered- no searching or shopping necessary. Room service at the Palmer! This food arrives (not in a steaming box, nor on a silver platter) courtesy of a black-gloved hand and is served at the end of a long pair of forceps (just stainless steel, not silver-plate). Initially, the offered food is a freshly thawed limpet. We collect these abundantly common 1-shelled molluscs during shallow dives. They are frozen and when needed thawed briefly in hot water. The animal pulls easily off the shell this way resulting in a limpet steak for each fish. Limpets are related to abalone, which grow much bigger and are I find quite delicious once cooked. The fish had little reluctance to their sushi, snatching the raw limpet steak off the end of the forceps.
The next level of training involves introducing the fish to the artificial food we will use as a base for the extracts. The cookie dough before flavorings added. Our dough is finely ground up krill powder mixed with thickener (alginate- used in people food too!) and cookie cutter-ed into small discs. The discs are then presented to the fish. This is where I get to exercise - my patience primarily. Some of the fish take a great deal of coaxing to try this new fangled food. It is high in protein, just like the limpet and will still keep Otis and pals in zone if they adhere to Adkins! Mikey, in Rm #4 is not a picky eater- ‘Hey, Mikey- he likes it!”
So, my fish training continues. I get my reps in at each feeding session. One set of 12, 3 times a day. I get a good stairmaster workout climbing up and down the ladder to the upper tanks. I also have an endurance workout – just how long can I hold my gloved hand in the cold water without loosing grip on a little krill jello-like disc between the tines of the forceps? I might need some coaching for my training to progress to extract level but in the meantime, I will just keep trying!