FRONT SEA STAR Genus: Asterias Species: forbesi Size: 13 cm (5 in.) radius Range: Gulf of Mexico to Texas ZOOXANTHELLAE Genus: Zooxanthella Species: Size: Microscopic Range: Tropical and temperate oceans CALCAREOUS GREEN ALGAE Genus: Halimeda Species: Size: 7.5 12.5 cm (3 5 in.) tall Range: Worldwide in tropical oceans PHYTOPLANKTON Genus: varies Species: Size: 2 200 µm (micrometer) in length or diameter Range: Worldwide in oceans, lakes, and ponds
BACK ZOOXANTHELLAE Natural History: Zooxanthellae live inside another organism in a symbiotic relationship. When exposed to sunlight, zooxanthellae use photosynthesis to produce their own food, some of which is transferred to the host organism. Food: Produced through photosynthesis Predator: Sea anemones, parrot fish, urchins, sea fans, and corals Shelter: Protected in the tissues of the host organism Reproduction: Divides into two new cells. When the host organism reproduces, zooxanthellae are present in the tissue of the offspring. Abiotic Impact: Needs light to survive. Productivity depends on light, water, and temperature levels. SEA STAR Natural History: The distinctive arms, or rays, have many small suckers, or tube feet, on the underside, with the mouth in the very center. Sea stars feed by wrapping their rays around a clam and forcing it open. Once a sea star gets a tiny opening, it everts its stomach into the clam, where it begins digesting the clam. Food: Clams, mussels, snails, sea urchins, corals, sponges, and worms Predator: Unknown Shelter: Sea stars are found in turtle-grass beds, on the sandy bottom, under rocks, and in crevices around coral in water 1 m (3.25 ft.) deep or deeper. Reproduction: Sea stars release eggs and sperm into the water. Larvae are planktonic for the first few months, and then settle down to become young sea stars. Photo: William Fitt, University of Georgia Photo: Kip F. Evans, Mountain and Sea Images PHYTOPLANKTON Natural History: Phytoplankton represent a huge array of microorganisms, mostly single-celled protists. The ones shown here are dinoflagellates. Plankton cannot move against the current, so they drift with water movement. Food: Produced through photosynthesis Predator: Zooplankton, bryozoans, fish, corals, sea anemones, worms, tunicates, sponges, sea fans, and brittle stars Reproduction: Most reproduce asexually by splitting into two new cells. Abiotic Impact: Productivity depends on light, water, and temperature levels. Human Impact: Runoff from sewage can cause huge population increases, called blooms, that can clog fish gills and prevent gas exchange. CALCAREOUS GREEN ALGAE Natural History: Halimeda at first may appear to be sea grass, but it is an alga. It forms green mats on the lagoon floor. These mats may cover several square meters. Food: Produced through photosynthesis Predator: Snails, limpets, amphipods, isopods, sea urchins, hermit crabs, other crabs, damselfish, parrot fish, lobsters, stingrays, and sergeant majors Shelter: The algal beds provide shelter for many small invertebrates, sea slugs, crustaceans, and worms. Abiotic Impact: Productivity depends on light, water, and temperature levels. Photo: William C. Jorgensen, Visuals Unlimited Photos: Homer Montgomery, University of Texas at Dallas
FRONT RED FINGER SPONGE CHRISTMAS TREE WORM Genus: Haliclona Genus: Spirobranchus Species: rubens Size: Up to 30 cm (12 in.) long; branch walls 3 cm (1.25 in.) thick Range: South Florida, Bermuda, the West Indies, and the Caribbean Species: giganteus Size: 12 cm (4.7 in.) long; branchiae whorls 4 cm (1.5 in.) Range: South Florida, the West Indies, and the Caribbean STAGHORN CORAL SEA FAN Genus: Acropora Genus: Gorgonia Species: cervicornis Size: Up to 3 m (10 ft.) tall; 1.5 m (5 ft.) wide; individual branches 2.5 cm (1 in.) diameter Species: ventalina Size: 75 cm (30 in.) tall; 75 cm (30 in.) wide Range: South Florida, Bermuda, Bahamas, and the West Indies Range: Florida Keys, Bahamas, the West Indies, and the Caribbean
BACK CHRISTMAS TREE WORM Natural History: The Christmas tree worm extends its branchiae when feeding. The branchiae function as gills to filter food from the water and to exchange gases for respiration. Food: Zooplankton, phytoplankton, zooxanthellae, and corals Predator: Sea urchins, flounder, parrot fish, lobsters, puddingwives, stingrays, schoolmasters, and sea stars Shelter: The main body of the Christmas tree worm is housed in a calcium-carbonate tube attached to rocks or coral. It expands its branchiae into the current to trap plankton. It quickly disappears into the tube if it senses any motion. RED FINGER SPONGE Natural History: Sponges are some of the most primitive of multicelled animals. The individual cells work together as a whole organism, but there is little specialization. The sponge feeds by drawing water in through tiny pores and up and out through the center opening. Plankton are trapped by the cells and digested. Food: Zooplankton and phytoplankton Predator: Angelfish Shelter: Red finger sponges live on coral reefs, in rocky areas, and in turtle-grass beds. Reproduction: Eggs and sperm are released in the water simultaneously. The tiny polyps float as zooplankton until they settle and begin a colony. Human Impact: Some species of sponge are collected for sale. Photo: Paige Gill, Florida Keys National Marine Sanctuary Photo: Cynthia Ledbetter, University of Texas at Dallas SEA FAN Natural History: Sea fans are a form of soft coral. They do not build a hard calcium-carbonate skeleton. They are flexible and sway with the currents. The tiny polyps filter-feed on the plankton that the current brings them. Food: Zooplankton, phytoplankton, zooxanthellae, and bacteria. Zooxanthellae that live within the tissue of a sea fan help nourish it. Predator: Parrot fish, butterfly fish, triggerfish, puffers, sea stars, sea urchins, snails, chitons, hermit crabs, clams, boring sponges, and polychaete worms Shelter: Rocks and reefs below the low-tide line Reproduction: Eggs and sperm are released in the water simultaneously. The tiny polyps float as zooplankton until they settle and begin a colony. Human Impact: Sea fans take hundreds of years to form the graceful, swaying fans. It takes only seconds for a collector to break them loose. Dried sea fans are collected for decorative uses. They are protected in marine sanctuaries. STAGHORN CORAL Natural History: Corals are colonial animals, with tens of thousands forming a large coral head. The tiny coral polyp lives only in the outermost section of the head. It builds outward, with new polyps attaching themselves to an established coral head. Food: Zooplankton, phytoplankton, zooxanthellae, and bacteria. Zooxanthellae that live within the tissue of coral help nourish it. Predator: Parrot fish, butterfly fish, triggerfish, puffers, sea stars, sea urchins, snails, chitons, hermit crabs, clams, boring sponges, and polychaete worms Shelter: Staghorn coral grows in protected areas of the reef, usually on the windward side in waters deeper than 3 m (10 ft.). Reproduction: Eggs and sperm are released in the water simultaneously. The tiny polyps float as zooplankton until they settle and begin forming their calcium-carbonate skeleton. Abiotic Impact: The coral provides protection for many small invertebrates and fish. Human Impact: It takes hundreds of years for coral to grow and a few seconds for a diver to snap off a branch. Coral has been heavily collected and sold for decorative uses. Coral is protected in marine sanctuaries. Photo: Cynthia Ledbetter, University of Texas at Dallas Photo: Florida Keys National Marine Sanctuary
FRONT FLAMINGO TONGUE SNAIL Genus: Cyphoma Species: gibbosum Size: 2.5 cm (1 in.) long Range: North Carolina to Brazil PARROT FISH Genus: Sparisoma Species: viride Size: 61 cm (24 in.) long Range: Bermuda to northeastern Brazil, including south Florida and the Caribbean WEST INDIES SPINY LOBSTER Genus: Panulirus Species: argas Size: Up to 61 cm (24 in.) long; 15 cm (6 in.) tall Range: In warm oceans from North Carolina to Brazil, including the Gulf of Mexico, Bermuda, and the West Indies LONG-SPINED BLACK URCHIN Genus: Diadema Species: antillarum Size: 30 cm (12 in.) diameter; spines 15 cm (6 in.) long Range: Florida, Bermuda, and the Caribbean
BACK WEST INDIES SPINY LOBSTER FLAMINGO TONGUE SNAIL Natural History: Lobsters are nocturnal hunters and emerge from their rocky shelter only when hunting. During the day only the antennae are visible. Food: Detritus (decaying organic material), sea urchins, worms, algae, tunicates, and turtle grass Predator: Octopuses and moray eels Shelter: The West Indies spiny lobster hides among rocks, sponges, and corals from the low-tide line to about 91 m (300 ft.) deep. Reproduction: Spawning occurs May through July. A male deposits a sac of sperm on a female's abdomen. The female inserts the eggs into the sperm sac for fertilization, and carries the eggs in grapelike clusters on small legs called swimmerets. The eggs hatch as larvae, which are planktonic for up to 8 months and then settle to the bottom to become young lobsters. Human Impact: The spiny lobster is heavily fished, and numbers are decreasing except around the Florida Keys. There are limits on the size that can be caught, so that the population can continue to grow. Photo: Florida Keys National Marine Sanctuary Photo: Paige Gill, Florida Keys National Marine Sanctuary Natural History: The bright black and orange spots on the flamingo tongue snail are not on its shell. The pattern is part of the mantle of the snail, which extends over the surface of the shell. If threatened, it can quickly withdraw this mantle. It regenerates patches that are torn or eaten away. Food: Sea fans, algae, turtle grass, and coral Predator: Sea stars, stingrays, lobsters, and schoolmasters Shelter: The flamingo tongue snail is almost always found grazing on sea fans, its preferred food. Its rate of grazing is often matched by the rate at which the sea fan can regenerate tissue. Human Impact: The flamingo tongue snail should not be collected for its striking appearance. Because the pattern is made of living tissue, it dies with the snail. LONG-SPINED BLACK URCHIN Natural History: The long-spined black urchin is the most abundant sea urchin in the Keys. Its spines make it invulnerable to most predators. The spines contain a mild toxin that gives a beelike sting. Food: Algae, turtle grass, phytoplankton, zooplankton, coral, zooxanthellae, sea fans, worms, sponges, and detritus (decaying organic material) Predator: Sea stars, porgies, triggerfish, and lobsters Shelter: Long-spined black urchins hide among turtle grass, coral, and rocks. PARROT FISH Natural History: Parrot fish are native to warm waters. The name comes from the beaklike mouth. Food: Parrot fish graze on the surface of corals. They scrape off the top layer, which houses the coral polyp. The calciumcarbonate skeleton of the coral passes unchanged through the parrot fish as the polyps are digested. While grazing on corals, they also eat worms, tunicates, algae, phytoplankton, zooplankton, and zooxanthellae. Predator: Barracudas, moray eels, and groupers Shelter: Coral reefs and sea-grass beds Photo: Nancy Sefton, Photo Researchers, Inc. Photo: Florida Keys National Marine Sanctuary
FRONT THREE-SPOT DAMSELFISH KNOBBED PORGY Genus: Eupomacentrus Genus: Calamus Species: planifrons Size: 19 cm (7.5 in.) long Range: Northern Florida to Venezuela, including the Gulf of Mexico, West Indies, and Caribbean Species: nodosus Size: Up to 46 cm (18 in.) long Range: Florida to the West Indies FRENCH ANGELFISH Genus: Pomacanthus Species: paru Size: Up to 36 cm (14 in.) Range: Bermuda to northern South America, including north Florida and the West Indies MORAY EEL Genus: Gymnothorax Species: moringa Size: 1.5 m (5 ft.) long Range: From North Carolina south to Brazil, including the Gulf of Mexico, Caribbean, and West Indies
BACK KNOBBED PORGY Natural History: The knobbed porgy is found in warm, shallow waters near shore. They occasionally venture into brackish and freshwater. Food: Smaller fish, long-spined sea urchins, tunicates, and other invertebrates Predator: Barracudas, moray eels, and groupers Reproduction: Porgies lay free-floating eggs and provide no parental care. Shelter: Reefs and ledges Human Impact: Common sport fish in Florida THREE-SPOT DAMSELFISH Natural History: Juveniles are bright yellow with a prominent blue-rimmed black spot. Adults are brown to black with three white spots on the forehead and upper sides. Three-spot damselfish are territorial and will defend the algal mats they feed on from other fish. Food: Phytoplankton, algae, zooplankton, and tunicates Predator: Barracudas, moray eels, groupers, and porgies Shelter: The three-spot damselfish lives near reefs in shallow, warm water. Human Impact: Juveniles are caught for saltwater aquariums. Photos: Fred McConnaughey, Photo Researchers, Inc.; Mark Smith, Photo Photo: Fred McConnaughey, Photo Researchers, Inc. Researchers, Inc. (inset) MORAY EEL Natural History: Morays have a row of sharp teeth and very strong jaws. They hide among rocks, often with their mouths open. If an unsuspecting fish swims in, it becomes dinner. Food: Smaller fish and crustaceans Predator: Barracudas and groupers Shelter: Crevices of rocks and reefs Human Impact: The meat of some moray eels is poisonous to humans. When snorkeling or scuba diving around rocks and reefs, never stick your hand into a crevice; a moray eel may be waiting for you. FRENCH ANGELFISH Natural History: Angelfish are active during the day and sleep at night. Food: Sponges. Angelfish specialize in a food source for which they have very little competition. Predator: Moray eels, barracudas, and larger fish Shelter: Shallow reefs Human Impact: Juvenile angelfish are a popular addition to home saltwater aquariums. Photo: Florida Keys National Marine Sanctuary Photo: Paige Gill, Florida Keys National Marine Sanctuary
FRONT ZOOPLANKTON BARRACUDA Genus: varies Genus: Sphyraena Species: Size: 100 µm (micrometer) to a few millimeters long Range: Worldwide in oceans Species: barracuda Size: Up to 1.8 m (6 ft.) long; 37.6 kg (83 lb.) Range: Massachusetts to southern Brazil, the Gulf of Mexico, the Caribbean, and Bermuda MARINE BACTERIA GULF FLOUNDER Genus: varies Genus: Paralichthys Species: Size: 1 3 µm (micrometer) Range: Worldwide in oceans Species: albigutta Size: Up to 38 cm (15 in.) long Range: Florida, the Gulf of Mexico, and the Caribbean
BACK BARRACUDA Natural History: Barracudas have large, spearlike teeth that point backward and can cut large pieces of flesh. Even though their primary food is fish, barracudas have been known to attack swimmers. Food: Smaller fish, squid, and shrimp Shelter: Barracudas live along the coast, in open water. Human Impact: Barracudas are aggressive and may attack swimmers and divers. The meat is often poisonous to humans and should not be eaten. ZOOPLANKTON Natural History: Zooplankton are microscopic adult animals and larval forms of animals. They represent nearly every group of animals found in the oceans. Like all planktonic organisms, zooplankton cannot swim well enough to move against currents, so they drift in the water. Food: Phytoplankton and marine bacteria Predator: Filter feeders, such as sea anemones, brittle stars, bryozoans, baleen whales, tunicates, barnacles, and fish Reproduction: Many zooplankton are larval forms of animals, such as crabs, lobsters, snails, octopuses, sea urchins, sea stars, barnacles, and fish. Others stay planktonic all their lives and reproduce by releasing sperm and eggs into the water. Photo: Florida Keys National Marine Sanctuary Photo: D. P. Wilson, Photo Researchers, Inc. GULF FLOUNDER Natural History: The Gulf flounder is a left-eye flounder; both eyes are on the left side of the fish's body. Food: Smaller fish, shrimp, small crustaceans, worms, and other invertebrates on the sandy ocean floor Predator: Barracudas, moray eels, and groupers Shelter: The Gulf flounder lies partly buried in the sand on its right side in water up to 128 m (420 ft.) deep. Human Impact: Gulf flounder is considered a good sport fish, and many are caught at night with spears. Because it is small, it is not considered good eating. MARINE BACTERIA Natural History: Marine bacteria float in the water and attach to substrates of all kinds, including rocks, sand, algae, animals, and any other organism they touch. Food: Detritus (decaying organic material) Predator: Filter feeders, such as sea anemones, brittle stars, bryozoans, baleen whales, tunicates, sponges, and barnacles Reproduction: Bacteria reproduce quickly via cell division. Photo: David S. Addison, Visuals Unlimited Photo: Paul W. Johnson, Biological Photo Service