Monsters of the deep

Science World, March 25, 2002 by Laura Allen

LIGHT IN THE DARK

Anglerfish's bizarre bodies are also perfectly built to survive below 1,000 m (3,281 ft), the point at which sunlight ceases to penetrate the ocean depths. How? They create their own light.

Like the majority of deep-sea species, most anglerfish can flash or glow an eerie blue or red light using gland-like organs called photophores embedded beneath the skin. The anglerfish's prize bioluminescent, or glow-in-the-dark, possession? A stalk-like projection called a barbel, which snakes up to 1 m (3.3 ft) long from the fish's chin or snout. The glowing stalk bobs tantalizingly toward prey, acting as both a searchlight and lure to coax victims into its gaping jaws.

While many mid-ocean fish feature bulging eyes designed to capture as much dim light as possible, dark-dwelling bathypelagic fish sport beady, minuscule peepers. Many fish in this zone possess no eyes at all--they're no longer a must when there's virtually no light! "They capture food by `touch.'" says Long. Well-developed nerves under their skin detect motion-induced vibrations from passing fish or shrimp. "Anglerfish can tell how far away their prey are, how big they are, and in which direction they're swimming," Long says.

FINAL FRONTIER

However grotesque, deep-sea creatures share one amazing trait--the ability to survive without much light, oxygen, food, warmth, or relief from crushing pressure. What other hideous faces, beastly bodies, and incredible adaptations lurk at those depths? Only the bathypelagic beasts themselves know for sure.

To learn about new deep-sea species and other mysteries to be uncovered in future NOAA expeditions, visit their Web site at: www.oceanexplorer.noaa.gov.

WATER WORLD: OCEAN

Scientists probe the deep ocean with camera-armed submersible vessels, but have only begun to penetrate deep-sea mysteries. The exact ocean zones and conditions in which many alien creatures exist are debatable. Care to meet some ghastly deep-sea dwellers?

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Lesson Plans

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Cross-Curricular Connection

Language Arts: Read 20,000 Leagues Under the Sea by Jules Verne. How is the novel different from real ocean explorations?

Did You Know?

* When the male deep-sea anglerfish finds a mate, he becomes a parasite. He attaches his teeth to the female and feeds off her. Eventually, their bodies are fused together permanently.

* There are 375 species of squids, and the cephalopods are speedy swimmers. Using the body and funnel, they can "jet-propel" backward at speeds up to 23 miles per hour.

* The deep-sea dragonfish has a long barbel extending from the chin or lower jaw. The bioluminescent protrusion is multipurpose. It's used to confuse predators, communicate with other dragonfish, and wave like a fishing pole to lure unsuspecting prey.

National Science Education Standards

Grades 5-8: populations and ecosystems * understanding about science and technology * structure and function in living systems

Grades 9-12: behavior of organisms * understanding about science and technology * interdependence of species