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Chap 15 Marine Life Classification

Chap 15 Marine Life Classification - Marine Life Marine...

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Unformatted text preview: Marine Life Marine Chapter 15 I. Monera bacteria that can photosynthesize: above, an image of blue­green algae (cyanophytes). Many cells are strung together into filaments. Many blue­green algae phosphoresce: they glow in the dark. They're especially noticeable in some waves breaking at night. II. Protista II. Protista Phylum Protozoa: animals of the Protist kingdom. Forams,note the tiny holes all over their shells (made of calcite) through which the cell extrudes as pseudopods (false feet). change shell type rapidly through time, making them useful for determining how old sediment is. The CaCO3 of their shells comes from CO2 in the water, so studying the C and O isotopes of the shells of these organisms tells us about temperature and salinity at different depths of water from ancient sediments. Radiolarians, their shells are made of silica. Phylum Chrysophyta: golden algae: diatoms, coccolithophores. They come in many shapes. These organisms prefer colder water and higher levels of nutrients than other floating plants. skeleton of silica (SiO2) bloom in areas of upwelling: cold water, nutrients one of 3 major sources for our petroleum form a brown foam at sea, a brown 'scum' in ponds; these are indicators that the water is clean­diatoms can't stand pollution Its shell is made of calcium carbonate. These prefer warm water and fairly low levels of nutrients. Very useful for determining age of sediment, Phylum Pyrrophyta: golden brown algae: dinoflagellates, zooxanthellae skeleton is an organic compound live in open ocean as well as coastal one of 3 major sources for petroleum blooms of certain species produce red tides; they exude a neuro (nerve) toxin that can produce paralysis, blindness, an inability to breathe These algal blooms can be deadly for animals: fish die off by the thousands, and swimming humans become very ill, paralyzed, or die from anaphylactic shock. blooms of Pfiesteria piscicida are now plaguing the Chesapeake Bay, MD, giving swimmers respiratory failure and memory loss Useful for age determination and water salinity, these are one of the few floating plants that live in very shallow water near the coast, where freshwater can reduce salinity. Zooxanthellae are the dinoflagellates that live inside coral animals. They help coral animals by providing them with food, III. Metaphytae III. Metaphytae Algae: 3 phyla of algae, each named for their color: red, brown and green. Very primitive red algae live in shallow water and may have a skeleton of calcite; brown algae include kelp; green algae may have a skeleton of calcite; include Penicillus, Halimeda Two forms of the red algae Goniolithon: encrusting on the left; upright, branching on the right. These organisms are adapted to low levels of nutrients and bright light. Red algae will only grow in very shallow, clear water. Kelp is a brown algae. Halimeda, a green algae with a calcite skeleton helping it 'stand up'. Phylum Tracheophyta: vascular plants: have some vessel (tube) that transports water from one place to another in the oceans, these live along the coast and include grasses and mangroves Mangroves grow in tropical climates The knotty mangrove roots help stabilize land by trapping sediment. Roots come down from its branches to help keep the plant supplied with oxygen (plants respire, too!). One of the few tracheophytes that can take being drowned part of the time and high and dry the rest of the time. IV. Metazoa IV. Metazoa Phylum Porifera: sponges The azure vase sponge and a brown, tubular sponge. suck water into their cells, remove any nutrients, and expel them back out through the large openings. a communal cluster of cells than a real, multicellular animal, but they can pump vast quantities of water through their bodies. Some sponges are predators. They slowly grow over a coral or other fixed animal and bore their way into the body. Phylum Ctenophora: combjellies Ctenophores or combjellies (above) look like jellyfish, but are a separate phylum because they have no stinging cells Not all have tentacles, but many bioluminesce (give off light, often as colors). Their colors flash on and off, through all the colors of the rainbow. They're often featured on TV shows about ocean life because of the beautiful color show they put on. Phylum Cnidaria: stinging tentacles: coral animals, jellyfish, sea anemones species of Acropora live communally with Zooxanthellae, a type of dinoflagellate, making the reef a sort of plant/animal organism. They continually grow upward Important requirements for healthy reef growth: 1) high levels of light (this means shallow water, clear water [no suspended mud]), 2) warm waters (tropics) and 3) low levels of nutrients. Remember what dinoflagellates do when they get high levels of nutrients. Coral animals and anemones live with their tentacles up; the jellyfish lives with its tentacles dangling down. The tentacles all have stinging cells at their tips. These all secrete a nerve toxin that stuns any animal. Some may have a hard hook that acts as a sting to inject the toxin. Humans are large enough that the small amount of nerve toxin doesn't stun us (unless we're already weakened by another condition), but it hurts pretty badly and leaves a red mark or a swollen welt if you get touched by one. The jellyfish moves about by floating, the coral animals and anemones are attached to the bottom. All cnidarians have a swimming larval stage. When the new organism is first born, it doesn't look anything like these, but looks like a tiny worm swimming about. After swimming to find food and growing for a while, it metamorphoses into the type of adult that gave birth to it: a floating jellyfish or it plants itself on the seafloor and becomes a coral animal or anemone These are all fairly primitive organisms (mouth=anus) but are advanced enough to fail the screen test, meaning they have real tissues: special tissues line the stomach and secrete enzymes that digest the captured prey. Even though stuck on the bottom, these are all meat­eaters. Phylum Bryozoa: a colonial organism Not nearly as abundant now as it was in the past,. The skeleton can grow to a foot or so, depending on the species. they have a digestive tract with a separate mouth and anus. They are found in cold to warm waters. In warm water areas they are minor components of the reef. In the Paleozoic, they were the reef, but those days are over for the bryozoan! 3 phyla of worms A tube worm, Protula tubularia,, and the brown­ banded social feather duster worm, Bispira brunnea, Some worms make a case or tube of calcite in which they live. Others burrow into the mud, while still others swim about and feed on other animals. The feather duster worms wave their feathery appendages in the water to trap whatever food particles happen by. It's better for them to live in a place with some current that helps bring food near. Worms can live just about anywhere. Some of them can even stand extremely low levels of oxygen. Phylum Brachiopoda: brachiopods look like clams superficially, but are more primitive. Brachiopods have a wave in their shell: the top half bows up, the bottom half bows in. This is how we tell their shells from clams. Phylum Mollusca: Phylum Mollusca: animals with a mantle, a thick, leathery skin. Class Gastropoda: snails. Some have shells, some don't. Those with shells have a coiled shell. Those without are either pteropods or slugs (called 'nudibranchs'). These have some of the most beautiful colors of any animal in the ocean. Snails and sea slugs exude a slime over which they crawl. Pteropods swim, There are 100s of species of sea snails, from abalone to limpets to whelks. Many snails eat algae by scraping it up with a tool in their mouths called a rasp. The rasp is a sharp object. Some snails are poisonous and use their rasp to inject poison into their prey. These snails are meat­eaters and are extremely dangerous to pick up. Conus is one species that has been known to kill humans who have picked it up. It's useful for you to know what these look like so you don't pick them up, even if you think they are dead! A sea slug or nudibranch (pronounced nude' eh brank). On the left are eyestalks, with eyes at the ends. On the right are a set of gills through which the animal breathes. Many of these are poisonous to the touch, as they secrete a toxin in their slime. Class Bivalvia: clams, oysters, mussels, scallops. "Bivalve" means 'two valves', or two shells hinged together. Bivalves dig into sediment, rest atop the sediment, attach themselves permanently to rock, or, in the case of scallops, they swim a bit. They generally have a tube (siphon) through which they pump water into their bodies and extract food particles from it. A few have the ability to bore their way into rock or even other clams. These may eat algae or are predators. They use the foot to dig themselves into soft sediment. Above, part of Tridacna, the so­called 'man­eating clam'. These grow in reefs, and the coral grow around them and cement them into place. They lie in the water with their 'mouth' permanently open, and they pump water through their bodies and extract food particles from it. How's a man supposed to get killed by this? Stick your head in it and get it stuck??? Their 'lips' (actually part of the mantle) are often colonized by algae, giving them lurid colors, such as purple or red. Class Cephalopoda: octopuses, squids, nautiluses These are all predators. These are all predators. They are among the smartest animals with the sharpest eyesight in the oceans. They grab their prey with their tentacles (which have suction cups on them) and bite them with a sharp, parrot­like beak. They change color rapidly. The octopus can also change shape rapidly and slither into very tight spaces. Some secrete nerve toxins!! Many of these are bioluminescent and live in deep, dark waters. Rumors have it these grow to enormous sizes, thanks in part to Jules Verne's 20,000 Leagues Under the Sea, in which a giant squid grabs the submarine. Fact or Fiction? Both octopi and squids can change color rapidly to disappear into their surroundings­ masters of camouflage! Phylum Arthropoda: 'jointed legs', hard outer skeleton (land forms include spiders and insects). horseshoe crabs Horseshoe crabs are not Horseshoe crabs are not really crabs They are meat­eaters, feeding mainly on clams, and can go for a year without eating. crustaceans: most abundant: copepods ('fecal express'), barnacles, krill, shrimp, lobster, crabs copepods copepods Copepods are tiny creatures­a mm or two in length and voracious eaters of forams, and all the one­ celled algae. They also eat small particles of sediment. Their fecal pellets are larger than the particles they eat, so they settle to the seafloor faster than the particles would if they were not packed into fecal pellets. Great thicknesses of copepod fecal pellets occur in the rock record. We call this method of getting tiny particles of sediment to the seafloor the 'fecal express'. barnacles­ These are strange little organisms that attach their heads to an object, such as a rock, a ship, or a whale, grow a little house of calcite and stick their feet out the door. Their feet have feathery appendages on them which trap food particles from seawater. shrimp and krill­ These all have an elongate tail that contains a powerful muscle. The animal kicks the muscle to swim. Humans catch shrimp to eat the muscle. Shrimp feed on detritus (dead things). A few are predators. Krill are a kind of small shrimp eaten by the millions by certain kinds of whales (baleen whales). They live all over the world but tend to concentrate in colder, polar waters. lobsters, crayfish, crawdads: Lobsters and their cousins, the crayfish, are detritus feeders. Those living in cold water have large claws for protection. Floridian lobsters do not have claws. Lobsters and crayfish live in marine to brackish water, depending on the species. If you've never eaten lobster before, eat only a little bit the first time. Lots of people are allergic to them and break out in hives when they eat them. crab crab There are 100s of species of crabs. They are detritus feeders and sometimes eat living things: small crabs, clams, seaweed. Each island in the ocean has its own unique set of crabs. They are an important component of the clean­up brigade. With care, you can learn to pick up live crabs from the back without getting pinched. The Blue Crab of the east coast is popular food. Like all arthropods, crabs molt. This means they shed their old shell and hang around as soft­bodies animals for a few hours until the new shell hardens. This is how they can grow larger. During the few hours­days that they are soft­ shelled, they are particularly vulnerable to being eaten. Soft­shelled crab is a delicacy: the whole thing is fried and eaten. Male crabs are 'jimmys'; immature females are 'sooks'. hermit crab, these guys use the shells of dead gastropods (snails) as added protection from predators. They haul their little homes about wherever they go. If you pick up a seashell, be carefull one of these isn't in it. They pinch, or, if unnoticed for a few days, sitting someplace in your house, they can start to smell pretty strongly. Phylum Echinodermata: water vascular system­totally bizarre. The echinoderms have a system of vessels in the same way that we have vessels to move blood around. But the echinoderms' vessels are filled with seawater. They have an efficient system of applying pressure and releasing it that makes the vessels allow the animal to move and feed. These are called 'tube feet'. The first time you pick up a living echinoderm, it will feel pretty strange as all those wriggling tube feet move like mad to escape you. The vascular system is often supported by a skeleton of calcite. starfish: Starfish can move amazingly fast. They grab clams or other echinoderms and crush them with their strong arms. This fellow apparently lost a leg or two in some disagreement with intended prey. The legs are growing back. sea urchins (spines!!), sand dollars, echinoids Sea urchins are covered in spines, many of which Sea urchins have poison in the tips. If there's no poison, getting the spine caught in your flesh will doubtless lead to infection. Best not to touch them. They gouge their way into living coral and feed off them. The star­shaped groove on the top emits a series of tube feet that guide food to the mouth, located on the underside. Echinoids feed from particles floating in the water, or they live in burrows which they form by eating. They eat the sediment, digest what's available, and excrete the rest. sea cucumbers A really delightful organism, it is largely a sack that pumps water through it to remove floating food particles, or it eats sediment When startled, it turns inside­out. Most animals run away from such a sight. These are a delicacy in some parts of the world, including right here in the U.S. brittle stars Brittle stars are smaller and Brittle stars are smaller and more delicate­appearing than starfish. Many use feathery extensions of their legs to trap particles of food from the water. crinoids: sea lilies a few dozen species, most of them discovered fairly recently. crinoids has the same legs as the starfish, but they extend upward into the water and have feathery tube feet that trap particles of food from the water. Most crinoids are anchored to the sea floor by a body part called the 'holdfast'. Phylum Protochordata: tunicates Most tunicates are small (a few inches at most) and swim or float. They filter food from the water. They have a notochord, a bundle of nerves that extends the whole length of the body. We also have a notochord that is protected by a hard part our bodies extrude: bone (the back bone). The back bone is made of separate units called vertebra. Tunicates probably gave rise to vertebrates. Phylum Chordata: animals with a notochord­ a long bundle of nerves. Most textbooks would split this group into two subphyla: those chordates without bone and those with bone. Those without bone include the lampreys and sharks. Fish: have gills Jawless fish: most primitive; Jawless fish: most primitive; lampreys This lamprey has no jaw, but he has a mouth. The mouth is a sucker and this fish attaches itself to other fish and sucks the life force from them. They were introduced into the Great Lakes by accident and have greatly reduced the numbers of native fish. Notice the row of holes along the side are the gills, through which this animal breathes. cartilaginous fish: sharks, skates and rays: these fish still have no backbone. There notochord is protected by a stiff substance called cartilage, the same stuff that makes up your ears and the soft part of your nose. This species can reach 4 m in length (that's 13 feet to you!). Shark must swim or they can't breathe. Their gills are fairly primitive, and only swimming pushes the water over them. Sharks depend on their teeth for survival, so it is important that the teeth stay sharp. Sharks have several rows of teeth, and are always growing new ones on the inside of the mouth, while teeth on the row on the outside are shed from time to time. Fossil shark teeth are fairly common in marine rocks. Sharks have a small bundle of nerves in their heads which passes for a brain. Sharks range in size from fairly small to the Great White, the biggest of which was 23 feet in length. Sharks really don't attack people, unless something strange has happened. Fear and overfishing have greatly reduced their numbers. Believe it or not, not all sharks are meat­eaters. Above is a nurse shark, which swims with its mouth wide open, filtering particles of food from the water, very much like crinoids, brachiopods, some clams, barnacles, and many other marine animals. It has no teeth. a relative of the sharks, a sting ray. These are predators. This particular one is electric, and stuns its prey with a touch of its barbed tail. Most rays (sometimes called 'skates') leave humans alone, except the ones humans feed regularly in the Bahamas. They are a nuisance there, always begging for handouts. This type of ray, the manta ray, is similar to the nurse shark. It swims with its mouth open and filters particles of food from the water. bony fish: 1000s salmon, tuna, seahorse, solefish, marlin, swordfish, etc etc etc a few important adaptations shared by all fish that have allowed them to become so successful in oceans (and freshwater) today: Fish have gills. Fish have Gills are organs used to extract oxygen from the water so the fish can respire underwater. What organ do we use to get oxygen? Fish actively suck water over the gills by opening their mouths, then when the water passes over the gill, it exits through gill slits. This is why fish swim with their mouths open. Jaws probably evolved from gills. In utero, humans pass through a development stage where we have gills on our necks. Fish have a lateral line system that helps them detect small changes in pressure. This is the way fish 'hear'. If you ever pick up a living fish, don't squeeze its lateral line, as you can damage this sensitive organ. The color of a fish above the lateral line helps the fish blend into its surroundings, so predators looking down on them can't see them as well. They don't bother to color their bellies, hence the term, 'fishbelly white'. Fish have a swim bladder. This is an internal organ that helps them keep the right position in the water (ie., the right water depth). Just as our heart beat speeds up or slows down when we need it to, without us thinking about it, the swim bladder responds to changes in pressure and helps the fish know where it is. The swim bladder is almost certainly the organ that evolved into lungs for higher organisms. Fish have body shapes that allow them to swim efficiently in water. Try running an eight­minute mile underwater and you will see that swimming is more efficient, and hav...
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