Biodiversity: There's a lot of life down there

Panels around sculpture base spotlight 32 spectacular organisms


Regalecus glesne
phylum Chordata

Once mistaken for a sea serpent, the oarfish is the longest bony fish, over 50 feet (17 m). The name refers to red fins that pivot as it swims, like oars on a boat §.
illustration © E. Paul Oberlander

Green turtle

Chelonia mydas
phylum Chordata

Sea turtles have an uncanny sense of direction; some migrate over a thousand miles to lay eggs. Like most sea turtles, green turtles are threatened by hunting and habitat loss.
photo © Tom Campbell

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These animals--all less than a millimeter long--live between sand grains. Meiofauna samples from a single bucket of sand taken off Florida may yield up to 22 phyla. The world's rain forests have 15 to 16 phyla of all kinds of organisms at most §.
illustration © Robert Higgins

Candy-stripe sea cucumber

Thelenota rubralineata
phylum Echinodermata

Like other sea cucumbers (relatives of sea stars and urchins), this species can shoot sticky poisonous tubular threads from its anus. The writhing tubules entangle an attacker, while the "victim" escapes to regenerate new tubules §.
photo © Mary Jane Adams

Common sea dragon

Phyllopteryx taeniolatus
phylum Chordata

Sea dragons reverse traditional sex roles. The male carries and incubates the eggs, which the female lays in a soft skin pouch under his tail. He stores the eggs until they hatch §. photo © Fred Bavendam

Pink vase sponge

Dasychalina cyathina
phylum Porifera

None of the five thousand or so species of sponges has specialized tissue. They simply filter water through pores in order to "eat" detritus and plankton §.
photo © David Wrobel

Giant purple jellyfish

Chrysaora sp.
phylum Cnidaria

Many marine animals remain to be discovered. This relative of corals and sea anemones was found in the early 1990s. Formal scientific identification of the species hasn't been published.
photo © Bob Cranston

Sea gooseberry

Pleurobrachia bachei
phylum Ctenophora

If disturbed at night, sea gooseberries (and other comb jellies) glow in the dark. At sea, people have reported waters filled with greenish comb jelly "fireworks." Even the embryos of this group light up §.
photo © David Wrobel

Clownfish and anemone

phylum Chordata and phylum Cnidaria

The mobile fish draws predators; the non-mobile anemone kills them with its stinging cells. The anemone eats; the fish gets leftovers and protection §.
photo © Michele Hall/HHP

Horsehair worms

phylum Nematomorpha

These are marine members of a mostly fresh-water group (their name comes from having been discovered in watering troughs). These parasites absorb nutrients through their body walls §.
photo © Oxford Scientific Films/Animals Animals

Goose barnacles

Lepas anseripera
phylum Arthropoda

Larval barnacles can swim, but adults use environmental cues to choose a hard surface for settling down. "Glued" in place, a barnacle stands on its head and uses its foot to scoop water (and food) into its mouth §.
photo © Oxford Scientific Films/Animals Animals

Vent worms

Riftia pachyptila
phylum Vestimentifera

Found only around sea-floor cracks, vent worms live in sulfurous hot water and rely on bacteria living in their body tissue for energy. Adults of this group do not have a mouth or digestive tract §. photo © Al Giddings/Images Unlimited, Inc.

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Peanut worm

Cloeosiphon aspergillus
phylum Sipuncula

The name comes from the shape they assume when they contract. Adults burrow in sand or dwell in crevices in rocks or coral. The long-lived larvae swim in warm surface waters the world over §.
photo © Kathie Atkinson/Oxford Scientific Films/Animals Animals


Chloeia viridis
phylum Annelida

For reproducing, many "bristle worms" have split personalities. They develop an extra body part containing sex cells (and even "eyes" and "feet" for swimming), which breaks off, rises to the surface, and releases the cells §.
photo © Woody Lee, Smithsonian Marine Station


Laqueus californiensis
phylum Brachiopoda

Often called lamp shells because of their resemblance to Aladdin's lamp, this ancient group has been around at least 400 million years, with 26,000 species in the fossil record. Only 335 species survive today §.
photo © David Wrobel

Pencil urchin

Heterocentrotus mammillatus
phylum Echinodermata

Sea urchins maintain ecological balance in coral communities by devouring algae that could outcompete the corals. Thick spines help stabilize the urchin in rough waters §.
photo © Bob Cranston

Arrow worms

phylum Chaetognatha

Billions of these small predators live in the upper layer of open seas. Named "hairy jaws," they have movable hooks to grasp and swallow prey--young fish, protists, copepods §.
photo © Peter Parks/Oxford Scientific Films/Animals Animals

Sea grass and kelp

Phyllospadix scouleri and Eisenia arborea
phylum Angiospermophyta (grass)
phylum Phaeophyta (kelp)

In the oceans, algae far outnumber flowering plants. The surf grass on the left is a flowering plant. The kelp on the right is a brown alga §.
photo © Jeff Rotman

Sea-star larva

phylum Echinodermata

Many immature marine invertebrates (which may not even look like the adults of the same species) drift over long distances §. This swimming sea-star larva will become a bottom-dwelling adult. photo © Peter Parks/Oxford Scientific Films/Animals Animals


phylum Dinoflagellata

Some of this group of one-celled, mostly planktonic organisms are plant-like and
photo © synthetic; others are animal-like and "eat" food. Some produce potent neurotoxins and may cause red tides that kill animals §.
photo © E. R. Degginger/Animals Animals

Brown algae

Macrocystis pyrifera
phylum Phaeophyta

For size, giant kelp has no rivals among sea plants and algae--it can grow to lengths of 260 feet (80 m) or more. Upper fronds, exposed to the most sunlight, can grow up to 2 feet (0.6 m) in a day §.
photo © Helmut Horn

Red algae

Maripelta rotata
phylum Rhodophyta

Red algae grow from the intertidal zone down to 900 feet (274 m) §. Their color allows them to absorb the parts of sunlight that penetrate deeper water. Agar (used to culture bacteria) comes from a species of red algae §.
photo © David Wrobel


Sarcodina radiolarida
phylum Actinopoda

With their elaborate skeletons of silica, these single-celled organisms are often preserved on the sea floor after they die. Buried in sedimentary rock layers, they mark changes in oceanic conditions §.
photo © Al Giddings/Images Unlimited, Inc.


phylum Foraminifera

Almost all of the 40,000 known species are fossils and microscopic. The white chalk cliffs of Dover, England, are deposits of calcium carbonate foram shells. Some forams are good oil-deposit markers §.
photo © Peter Parks/Norbert Wu

Blue-green algae

phylum Cyanophyta

These photosynthesizing bacterial cells may have released oxygen into the primordial atmosphere §. Although most are blue- green, one can appear red--it colors the Red Sea §.
photo © Sinclair Stammers/Science Photo Library/Photo Researchers, Inc.

Blue whale

Balaenoptera musculus
phylum Chordata

Larger than any animal ever (including dinosaurs), the blue whale has a heart the size of a car. An adult sucks in 45 tons of water in a gulp, and filters out 3 to 4 tons of small shrimp and fish daily §.
photo © Doc White/Ocean Images, Inc.

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Sea hare

Aplysia sp.
phylum Mollusca

Sea hares, unlike their relatives the snails, don't have shells. Instead, they release purple ink for escape and toxic white fluid for protection when disturbed §.
photo © Mike Severns/Tom Stack & Associates


Reticulammina labryinthica
phylum Xenophyophora

These giant single-celled organisms can be seen by the naked eye, yet little is known about them. They've been found only on the sea floor. In some Pacific trenches, half the bottom is covered by slime they produce while feeding §.
photo © Institute for Oceanographic Sciences Deacon Laboratory


Pleurosiama balticum
phylum Bacillariophyta

The remains of billions of silica diatom shells have made history--geologic, biological, and even industrial. Alfred Nobel used diatomaceous earth to stabilize nitroglycerine when he invented dynamite §.
photo © Peter Parks/Norbert Wu

Sea otter

Enhydra lutris
phylum Chordata

Sea otters help to keep kelp healthy by eating the sea urchins and abalones that graze on kelp. When 19th-century hunting almost wiped out California sea otters, grazers destroyed giant kelp in some areas §.
photo © Tom Campbell

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Marine viruses

viruses don't belong to a phylum

These bits of genetic material coated with protein aren't really living organisms (they can't reproduce outside of host cells-- mostly bacteria). From 50,000 to 50 million marine viruses can be found in a teaspoon of sea water §.
electron micrograph © John Waterbury, Woods Hole Oceanographic Institution

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Ocean Planet Exhibition Floorplan

gene carl feldman ( (301) 286-9428
Judith Gradwohl, Smithsonian Institution (Curator/Ocean Planet)