Transcript Platyhelminthes – the flat worms

Chapter 5
By Coach Murray
Sponges – Filters of the Sea (5-30)
• Phylum Porifera – 10,000 species mistaken for
plants, heterotrophs, up to 16 ft wide, filter 20
x volume in 1 min., secrete mucus to avoid
clogging
• Multicelluar: collar cels (move H2O),
amoebocyte (absorb/distribute nutrients),
osculum (or oscula),
Sponges – Filters of the Sea (5-30)
• Special Attributes of Sponges
– Larvae are free swimming and attach themselves
to reef/structures and begin growing into adults
– Defense: needlelike spicules (Fig 5-30 in green)
made of glass/calcium or some secrete toxic
chemicals
– Can regenerate
Coral, Anemones, Sea Fans, and
Jellyfish (5-33)
• Phyllum Cnidaria – soft/hard corals, sea
anemones, hydroids, sea fans, and jellyfish
– Radial symmetry, umbrella shaped body polyp or
medusa (tentacles/mouth facing up or down)
– Nematocysts – stinging cells on tentacles
Examples of Cnidarians
Cnidarian Anatomy
Speical Attributes of Corals and
Anemones
• Phylum Cnidaria, Class Anthozoa – 6000
species of sessile polyps (corals and
anemones)
– Hard corals build reefs made of calcium carbonate
grow for 100+ yrs and shape entire coastlines
– Feed at night on drifting plankton and look fuzzy –
tentacles of genus Symbiodinium a dinoflagellate
– Corals get their color from these dinoflagellates
Special Attributes of Fire Corals and
Siphonophores
• Class Hydrozoa – colonial, alternate b/w polyp
and medusa in their lifecycle
• Examples: Portuguese man-of-war
– Has a fish like wish the same name
• Siphonophores all sting
Special Attributes of Jellyfish
• Class Scyphozoa – jellyfish, drift w/current,
pulsate bodies to move, eat plankton + fish,
grow up to 10’ long, larvae blooms can cause
clouds 100 mi. long, prey of Leatherbacks/fish
– Examples
• Box Jellyfish
– Kills humans
Simple Marine Worms (5-41)
• 22 Phyla of 32 animal Phyla are worms
(Whoa!)
• You need to know 3 Phyla
– Platyhelminthes – flat worms, mostly parasitic, 1
opening in body
– Nemertea – semi-flat worms, carnivores,
– Nemotoda – round worms, parasitic, 1 way
digestive system,
Simple Marine Worms (5-41)
Platyhelminthes – the flat worms
Simple Marine Worms (5-41)
Nemertea – the ribbon worms
Simple Marine Worms (5-41)
Nematoda – round worms
Mollusks – Bag, Scraper, and a Foot (543)
• Phyllum Molluska – 100,000 species, 3 classes
– Classes Gastropoda , Bivalvia, and Cephalopoda
• General Characters of all Mollusks (Fig 5-46)
– Mantle = muscular bag for motion/feeding
– Muscular foot/tentacles, radulla are like teeth
Special Attributes of Class Gastropoda
• Characters: (most have 1 shell) snails, slugs,
sea slugs, conch
• Undergo torsion in development: body twists
into a loop that rearranges organs and bring
them back together into a spiral shell
• Those w/o shells use toxins for defense
Special Attributes of Class Gastropoda
Special Attributes of Class Bivalvia
• Characters: (2 hinged shells) – no head,
mantle acts as bag for filter feeding
• Close shell for protection, pearls form layers of
nacre (dirt surrounded by calcium carbonate)
• Ex. 10,000 species of clams, oysters, and
scallops
Special Attributes of Class Bivalvia
Special Attributes of Class
Cephalopoda
• Characters: (head-footed) – cuttlefish, squid,
octopii
• No shell, muscular foot = tentacles/arms, eyes
• Siphon – water propeller
• Chromatophores – color changing cells
• Suckers for gripping
Special Attributes of Class
Cephalopoda
Echinoderms – Stars of the Sea (5-57)
• Phylum Echinodermata = means “spiny skin”
– Exoskeleton, madreporite, water vascular system,
tube feet, radial (adult), bilateral (larvae),
eyespots
• Examples: starfish, sea urchins, basket stars,
Echinoderms – Stars of the Sea (5-57)
• More Phylum Echinodermata Examples: Sand
dollar, sea cucumber
Crustaceans- Underwater Arthropods
– (5-51)
• Phylum Arthropoda – (“bugs”)1 million
species, segmented bodies, jointed legs,
exoskelton of chitin.
– Superclass Crustacea – 2 antennae, manibiles for
chewing, pair of appendages for each body
segment, molt their exoskeletons
Crustaceans – Underwater Arthropods
• Special Attributes of Class Cirripedia
– Barnacles
– Free swimming larvae fuses itself to hard surface
– Has a carapace and uses cirri to gather food
Crustaceans – Underwater Arthropods
• Class Copepoda – small, teardrop shaped, <
1mm (5-53)
• Eat phytoplankton and zooplankton
• Eaten by fish, krill, whale sharks, baleen
whales
• Fecal pellets recycle ocean nutrients rapidly
Invertebrate Chordates (5-62)
• Characters
• Examples
Vertebrates – 40,000 species
• Phylum Chordata, Subphylum Vertebrata (64)
– Characters of Subphylum Vertebrata
– Top of all food webs, large, fast, complex, highly
developed organisms w/ 4 limbs, complex eyes
– Anthropomorphism - making human things
human when they are not
Vertebrates (The Significance of Class
Agnatha 5-64)
• Jawless fish, shark/bony fish ancestor(?)
where 1st three gill arches became the jaws of
bony fish/sharks
• Ex. Lampreys, hagfish, eels
Sharks and Rays – Teeth and Wings (565)
• Class Condrichthyes, Subclass Elasmobranchii:
1000 species, have jaws, skeleton of cartilage
a swim bladder, lateral line, gill slits, energy
efficient, quick, inconspicuous predator
• Efficient: cartilage lighter than bone, fins sit at
angles and asymmetrical tails to provide lift,
elastic skin, denticles not scales, teeth grow as
conveyor belt (25,000 teeth in lifetime)
• Ampullae of Lorenzini for electroreception
Sharks and Rays – Teeth and Wings (569) Continued
• Class Condrichthyes, Subclass Elasmobranchii:
– Most do internal fertilization, few (1-10) mature
offspring – some species do lay eggs
– Shark fin soup is made by catching the sharks,
cutting off the fins and dumping the shark
overboard
– Size of your hand to 46ft (Whale shark)
Subclass Elasmobranchii
Subclass Elasmobranchii
Bony Fish – Half the World’s
Vertebrates – 25,000+ (5-73)
• Characteristics of Bony Fish– Class Osteichthyes
– Skeleton of bone, true jaws, scales, external
reproduction (100++ eggs), fusiform shape
– swim bladder (buoyancy control – get Nitrogen
from bloodstream)
– Lateral lines (detect vibrations – schooling and
feeding), countershading (dark top, bright
underside)
Swim Bladder
What is it? What does it do?
•Internal organ – an oblong
gas sack
•Controls buoyancy in the
water column
•Filled with Nitrogen and
Oxygen gas
•Gas comes from 2 places:
gulping or from the
bloodstream
References:
http://www.glossop-sea-anglingclub.co.uk/webpages/venting_files/bladder1.gif
Lateral Line
• A system of hollow fluid
filled canals
• Most species can be seen
externally
• Allow the fish to detect
motion and vibrations
• Important for:
– Schooling
– Predator detection
– Prey detection
•
•
•
References
http://www.hatchesmagazine.com/images/12806.04.01.jpg
http://www.amazonianfish.co.uk/images/plagioscon_squamosissimus.jpg
Fusiform
Structure: A type of shape…..
Side view: Spindle shaped which
is broader at the head and a Vshaped tail.
Front view: compressed
Function: reduces drag and
turbulance
References:
http://www.fullpullsportfishing.com/images/fish/bf_tuna.jpg
http://www.marinebiology.org/images/bodyshape.GIF
Special Attributes of Orders
Clupeiformes and Gadiformes (5-75)
• Clupeiformes
– Small silvery fish, low on food chain (eat diatoms)
– Account for ¼ of all fish caught
– Ex. Anchovies, sardines, pilchards
• Gadiformes
– 1/6 of fish catch but close to commericial
extinction
– Ex. Cods, whiting, and haddock
Gadiformes
Melanogrammus aeglefinus - Haddock
Gadiformes
Ophiodon elongatus - Alaskan Ling Cod
Marine Reptiles – Cold Blood and
Warm Water (5-77)
• Characters: few live in ocean, cold blooded,
have lungs, internal reproduction(eggs)
• Order Crocodilia – alligators, crocodiles, and
caimans
• Lives in estuaries, not truly a marine species
Order Crocodilia – Alligators, Caimans,
and Crocodiles
Gators and Caimans vs. Crocs
• Jaw/Snout/Nose Width
– Gators and Caimans: U shaped nose, wide jaws, built for
crushing turtles shells
– Crocs: more V shaped nose, narrow jaws
Gators and Caimans vs. Crocs
• Tooth Placement
– Gators: lower jaw more narrow so teeth in bottom jaw
almost hidden
– Crocs: upper and lower jaw the same size, top and bottom
teeth interlock and show
– Crocs: large 4th tooth
Special Attributes of Marine
Crocodiles, Turtles, Snakes and Lizards
• Order Chelonia (turtles and tortoises) – 7
marine species which eat plants/animals, all
bycatch hazards, lay 100 – 120 eggs in dunes
• Ex. Green sea turtle, Leatherback
• Order Squamata – 61 sea snake species, cobra
relatives, deadly venom,
– Marine iguana only marine reptile – swims, dives,
and is an herbivore (algae), Galapagos native
Order Chelonia
– Chelonia mydas (Green sea turtle)
Order Chelonia – Caretta caretta –
Loggerhead sea turtle
Order Squamata
Aipyisurus lavevis – Olive sea
snake
Laticauda colubrina – Banded
sea snake
Seabirds – At Flight Over and In the
Ocean (5-81)
• Characters: Class Aves – 10,000 feathered
species of birds, forelimbs, 4 chambered
heart, internal fertilization of eggs,
• Prey on: fish, crustaceans, mollusks,
Predators: sharks
• Indicate marine ecosystem health, guano
• Adaptations: bills, longer wings, webbed feet,
Marine Mammals – Warm Blood in
Cold Water (5-83)
• Class Mammalia:
– top of food web, need extra energy for
thermoregulation, breathe air
– Have myoglobin, mammalian diving reflex, flexible
skin, echolocation (dolphins and whales)
• Examples
– Dolphins, whales, seals, sea lions
Can you name
these 3
pinnipeds?
Special Attributes of Seals and Sea
Lions
• Order Pinnipedia – examples and characters
– Seals: no ear flaps, hind flippers point backwards,
crawls on stomach
– Sea Lions: ear flaps, hind flippers can rotate hind
flippers forward, sit more upright, run by pivoting
– Walrus: no earl flaps, can rotate hind flippers like
sea lions
Special Attributes of Dolphins, Whales,
and Porpoises (5-86)
• Order Cetacea – fish like mammals, breathe
through dorsal blow holes, no hind limbs,
muscular tail, blubber
• 2 suborders – use echolocation
(hunting/communicating)
– Mysticeti – baleen whales (humpback, gray, blue),
all big b/c consume at bottom of food chain
– Odontoceti – toothed whales (sperm whale, orcas,
dolphins, porpoise) , keen ability to learn
Special Attributes of Dugongs and
Manatees
• Order Sirenia (4 species, all mammals +
herbivores)
– Manatees – elephant relative, rare, killed by boat
screws, aka “sea cow”, native to northern S.
America
Marine Mammals and Human
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