Giant Squid – Stealthy Predator and Prey

• Scientists in a submersible sub recently photographed a giant squid deep in the ocean – the first time a live giant squid had been seen in its natural habitat. This one was silver and gold in color and measured about 30 feet in length, from the tip of its two longest tentacles to the rear of its body.

Of its eight tentacles, the two longest are known as “feeding tentacles.” They are flattened at the end and festooned with hundreds of suckers edged with sharp teeth. They reach out in the darkness and capture jellyfish and fish, then guide them to the hard beak-like mouth at the base of the tentacles. There, the beak slices the prey into bite-size pieces. These pieces pass over the squid’s long tongue, which is covered with very sharp little teeth; the tongue acts upon food pieces by sliding back and forth, like a rasp, breaking the food down even smaller for swallowing.

The huge eye of a giant squid, more than 10 inches in diameter, enables it to see prey in very dim light. Some of its prey gives off light in the form of bioluminescence when disturbed. Giant squid can detect the presence of its main predator, the sperm whale, because as the whale approaches it disturbs bioluminescent plankton and other creatures, leaving a glowing trail behind. It is estimated that a giant squid can see a sperm whale approaching up to about 400 ft. away. (Live Science, Nov. 27, 2012; ocean.si.edu/giantsquid, Jan. 25, 2013; discovery.com, Jan. 25, 2013)

• Pharmaceutical companies face difficult challenges when developing drugs to treat mental illness. The brain is a complex system of interconnected circuits driven by chemicals and electrical impulses that are constantly being altered by the environment. No wonder it is difficult to study. It is also difficult to design psychoactive drugs to effectively treat the one in four Americans who suffer some kind of mental illness each year. Because the brain is so complex, drug companies are beginning to back away from spending millions of dollars to bring new psychoactive drugs to market.

In general, it takes about 18 years and $66 million or more to go from preclinical experiments to public availability. Initially a newly developed drug is tested on mice or rats to see if its effects might be applied to humans. But the jump from mouse to man is a big one, and some scientists are becoming discouraged about the efficacy of rodent models. One researcher said he was “… tired of curing mice.” A psychiatrist argued “… it has been 30 years since a drug has been developed to treat mental illness in a novel way.”

When a promising psychoactive drug reaches final human trials, there is always the possibility that it works for some people and not for others. Is this a failed drug? Some researchers would say yes, while others point out that it is not unusual for a given drug to benefit one person and not another. Finally, it is worth noting that many existing psychoactive drugs are modifications of drugs developed in the 1950s for other disorders. For example, a drug synthesized in 1950 to be used as an anesthetic is now used as an antipsychotic; another drug, imipramine, a failed schizophrenia drug, was reformulated and is now used to treat depression. (Science News, Oct. 23, 2013; T. Insel, Science Translational Medicine, Oct. 10, 2012)