Ivan Pavlov famously conditioned dogs to salivate every time they heard a dinner bell. The U.S. Army hopes to use a similar technique to train fish in Buzzards Bay off the coast of Massachusetts. According to the
Cape Cod Times, the experiment:
houses 5,000 juvenile black sea bass in a dome-shaped structure at the bottom of Buzzards Bay, for the purpose of feeding them after playing a 280 Hz tone. The study is being led by Scott Lindell, director of MBL's Scientific Aquaculture Program, to determine whether the caged fish — once accustomed to the tone then released into the wild — will return to the dome for recapture when the tone is played. The hope is to create a less harmful way to fish or better replenish natural fish stock, project officials told the Times in March.
The experiment has raised concerns among a consumer advocacy group, who are suing the Army, but that's not what interests me. What interests me is whether the fish salivate when they hear the tone. Do fish, in fact, have salivary glands? An answer from
genuineideas.com:
Although the most well developed glands are found in mammals, many other vertebrates and invertebrates have salivary glands. Fish and other aquatic animals clearly do not lack opportunities to add water to their meals; hence most aquatic animals are devoid of "true" salivary glands. However, some form of lubrication is still necessary to assist swallowing even in water, and this is provided by mucous glands along the tongue and roof of mouth (Mucous secretion is present in all animals.)
And that's your weird fish fact of the day.
Category: Animals | Experiments