Presentation on theme: "Phylum Chordata A Chordate is an animal that has 4 specific characteristics during their life cycle: 1- Dorsal, hollow nerve cord 2- Notochord – a long."— Presentation transcript:
1 Phylum ChordataA Chordate is an animal that has 4 specific characteristics during their life cycle:1- Dorsal, hollow nerve cord2- Notochord – a long supporting rod that runs through the body below the nerve cord3- Post anal tail4-Pharyngeal pouches (gill slits)
2 1- A Dorsal, Hollow Nerve Cord This is a sheath of large nerve cellsThese nerve cells are somewhat like stem cells in they may play an important role in other nerve cells that developExample: certain motorneurons are affected by the absence of these cells in embryonic developmentIn higher organisms, the actual “spinal cord” is surrounded by this hollow covering.
3 2- A NotochordThe notochord is a strong structural part of the organismIt is located dorsally from the gut (endoderm and coelom)It is made of cartilage or boneIt is the spine, or vertebral column
4 3- A Post Anal TailPost means it is located posterior to the anus, or behind the anusIt is an extension of the notochord, and made of cartilage or bone
5 4- Pharyngeal pouchesThese are located at the pharynx, or throat, of a chordateThey develop into the gills of fish and juvenile amphibiansIn aquatic reptiles, birds and mammals, they close during embryonic development and become the throat, while the nasal passageways develop
6 Subphyla of the Phylum Chordata The Nonvertebrates:Sub Phylum Urochordata tunicates or “Sea Squirts”Sub Phylum Cephalochordata – lanceletsThese are very simple chordates without spinesAll are aquatic
7 Subphyla of the Phylum Chordata The VertebratesSub Phylum Vertebrata– cartilaginous and bony fish, amphibians, reptiles, birds, mammalsThese are chordates with spines of cartilage or bony tissue
8 Vocabulary Body temperature control: Ectotherm – animals that rely on behavior and interactions with the environment (Cold-Blooded)Endotherm – animals that generate their own body heat and control temp. from within (Warm-Blooded)
9 Vocabulary Egg to Juvenile Method: Oviparous – Eggs hatch outside the female bodyEx: Most FishOvoviviparous – Eggs develop inside the female body and the young are live-bornEx: Some Sharks)Viviparous – bear live young that are nourished directly by the mother’s body as they develop.Ex: Whales, Otters
10 Vertebrates – Agnathans (jawless fish) Examples: Lamprey; HagfishBody Plan: snake-like, no scales, no paired fins, no true teeth or jawsSkeleton Type: fibers and cartilage2 chamberedTemperature control: ectothermRespiration: gillsReproduction: sexually-external/ internal fertilization (oviparous)Importance: lamprey are parasites and hagfish are decomposers that feeding on dead or decaying fish)
11 Vertebrates – Class Chondrichthyes Examples: Sharks, Rays, SkatesChondros (Gk = cartilage)Body Plan: large curved tails, torpedo-shaped body, pointed snout, moveable jaw, placoid (rough as sandpaper)scalesSkeleton Type: cartilage2 chamberedTemperature control:ectothermRespiration: gillsReproduction: sexually- external/internal fertilization (oviparous/ovoviviparous/some viviparous)Importance: predators in the food chain
12 A skate is shown in the top picture; a stingray below As the front row of shark teeth are worn out, new teeth are continually replacing them. A shark goes through 20,000 teeth in its lifetime!!A skate is shown in the top picture; a stingray below
13 Vertebrates – Osteicthyes (bony fish) Examples: goldfish, perch, bass, troutBody Plan: lateral line (use this to sense motion of other fish nearby), swim bladder (internal, gas-filled organ that adjusts buoyancy), scalesSkeleton Type: hard, calcified tissue called bone2 chamberedTemperature control:ectothermRespiration: gillsReproduction: sexually-external fertilization(97% are oviparous)Importance: prey in the food chain, fishing industry
14 Bony Fish Types Saltwater Brackish water Freshwater Strictly live in water with dissolved salt content near seawater, about 35 ppt in the open oceanMust regulate the loss of freshwater out of their bodies as natural osmosis and diffusion seek to balance salt concentrations within and surrounding their bodiesEx: marlin, mullet, snapper; flounderBrackish waterRequire salinities between 35 ppt and freshwaterMany marine fry are hatched in brackish water then migrate to open oceans as they matureEx: fry; sheepshead, croakerFreshwaterStrictly live in freshwaterMust regulate the increase of freshwater into their bodies as natural osmosis and diffusion seek to balance salt concentrations within and surrounding their bodiesEx: blue catfish; bluegill, hybrid bass
15 More Types of Fish Catadromous Anadromous These fish hatch in marine waters and then migrate into freshwater to spend adulthoodThey return to marine waters to spawnEx: Eels are the most common fish to do this, and the Sargasso Sea, near the southern part of the Atlantic Gyre, is their famous spawning groundAnadromousThese hatch in freshwater and then migrate into marine waters to spend adulthoodThey return to freshwater to spawn, and then usually dieEx: Salmon, shad, smelt and sturgeon are examples.
16 Things you must know: Fish External Anatomy Fish Internal Anatomy All finsLateral lineScale TypeFish Internal AnatomyFish Organ SystemsFish MorphologyBody Shape that indicates ecological nicheFish BehaviorsMating, Territoriality, ParentingIdentifying and “Keying Out” FishWhat class are they in
17 Vertebrates - Reptilia Examples: snakes, lizards, turtles & tortoises, crocodilesBody Plan: dry, leathery skin, thick scales made of karatin (smooth or rough), terrestrial, amniotic eggs (shell & membrane so egg can develop out of water)Skeleton Type: hard, calcified tissue called bone3 chambered except crocodiles with 4 chamberedTemperature control:ectothermRespiration: lungsReproduction: sexually-internal fertilization – eggs laid on land(most oviparous/ some ovoviviparous)Importance: control rat populations, medical use/research, clothing industry
18 Turtles make a nest and lay their eggs on land. Snakes are carnivorous and stretch their jaws to consume their prey whole.The sex of a crocodile is determined by temperature, with males produced at 88 F, and females produced at 80 F and 93 F.
29 NestingVery little is known why sea turtles nest on some beaches, and not on othersMost females return faithfully to the same beach each time they nest
30 Females nest usually at night “false crawl” – occurs when female turns back and decides not to nest
31 Females lay 100-160 eggs in a nest that hatch about 60 days later
32 Females appear to “shed” tears as they lay, secreting salt that has accumulated in her body Covers with rear flippers and disguises the nest
33 Incubation & Emergence About 60 daysThe hotter the sand, the faster they hatchWarmer sand – more femalesCooler sand – more males
34 Hatchlings use a temporary, sharp egg- tooth called a “caruncle” to break open the shell Caruncle then falls off
35 Digging out of the nest is a group effort that takes days Emerge from nest in a group
36 Orient themselves to the brightest horizon Only about 1 in survives to adulthood
37 Vertebrates – Amphibia (“double-life”) Examples: frogs, Toads, newts, salamanderAs larvae usually live in water and as adult live on landBody Plan: moist skin with mucus glands, lack scales/claws, undergo metamorphosisSkeleton Type: hard, calcified tissue called bone3 chamberedTemperature control:ectothermRespiration: young=gillsadult=lungsReproduction: sexually-external fertilization(oviparous) or internal (salamanders)Importance: control insect populations, medical/ pharmaceutical use, food source (frog legs) in India/Asia
39 Vertebrates – Aves (birds) Examples: chickens, penguins, cardinals, ostrichBody Plan: feathers of protein/keratin (flight/warmth), two legs covered in scales, front limbs modified into wings, thin hollow bones (helpful for flying)Skeleton Type: hollow, calcified tissue called bone4 chamberedTemperature control:endotherm (can generate own body heat)Respiration: lungs, includespassageways of air through air sacsReproduction: sexually-internal fertilization - oviparousImportance: control insect populations, food source, clothing, bedding, hunting purposes
41 Aquatic Birds have special adaptations… Their feathers are highly resistant to being wettedThey usually have higher oil production than other birds from glands at the base of the tailThe oil is applied to the feathers during preeningPreening is birds grooming activity; they run their beak through their feathers to straighten and comb themDuring preening oil is spread lightly over feathers to help keep them water resistantDry feathersKeep birds warm when in aquatic sitesAre easier to use for flight (think about a paper airplane that is dry vs. one that is wet!)
42 More special adaptations… Aquatic birds also have special appendages…Feet are webbed for swimmingLegs may be longer to wade in waterLong toes spread out to distribute weight in mudBeaks are modifications like the following:for grasping wet, slippery preyHooked tips on eaglesThe huge “baskets” of pelicans,spear-like points in herons, cranes and egretsfilters of flamingosBeaks modified into bills for duck- and goose-like creatures for sifting worms and arthropods from mud, or for catching fish underwater
61 Albatrosses Nest on land, live at sea Wingspans can reach 11 feet.
62 Arctic TernsHave the greatest migration of any bird. They venture from pole to pole every year- a voyage of 22,000 miles.
63 Hazards for Sea BirdsPlastic debris- ingest plastic materials because it fills the stomach, but lacks nutrients and cannot be passed.
64 Oil slicks saturate the feathers, destroying the ability to insulate, let alone be able to fly. The loss of insulation alone can be fatal
65 The greatest danger to seabirds is…. rat and mouse invasions The greatest danger to seabirds is…. rat and mouse invasions. The mice consume the bird’s eggs in huge numbers, causing significant bird population declines on some Pacific Islands.
66 Vertebrates - Mammalia Examples: cats, whales, gorillas, zebras, humansBody Plan: mammary glands (produce milk to nourish the young), have hair, breathe air, bear live youngSkeleton Type: hard, calcified tissue called bone4 chamberedTemperature control:endotherm (can generateown body heat)Respiration: lungsReproduction: sexually-internal fertilization (viviparous)Importance: food, hunting, clothing, medical research, pets
67 Mammalia Reproduction Diversity Monotreme – “egg-laying mammal”; like reptiles except after eggs hatch the young is nourished by mother’s milkOnly 3 species exist: duckbill platypus, 2 spiny anteatersMarsupial – bear live young that complete their development in an external pouchKangaroos, koalas, wombatsPlacental – nutrients, O2, CO2, wastes are exchanged b/n embryo and mother through placentaElephants, rabbits, humans