ctenophores comb jellies-videovideo. all marine 100 species radially symmetry and gelatinous body...
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CTENOPHORES
COMB JELLIES-video
All marine 100 species Radially symmetry and gelatinous body Swim with 8 rows of CILIARY COMBS, long
cilia fused at the base that beat in waves reflecting light
In warm and cold waters COLLOBLASTS- long tentacles armed with
sticky cells
www.mwra.state.ma.us/.../graphic/ctenophore.jpg
Comb jelly
BILATERALLY SYMMETRICAL WORMS
FLATWORMS, RIBBON WORMS, NEMATODES, SEGMENTED WORMS-
VIDEO
FLATWORMS
Phylum- Platyhelminthe Dorsoventrally flat Simplest animals with tissues organized into
real organs and organ systems Have a central nervous system
Simple brain- bundle of nerve cells Several nerve cords the length of the worm Only one opening for gut/anus
Embryos have a middle layer of tissue called the MESODERM (1st animal to have it)- which gives rise to muscles, the reproductive system, and other organs
20,000 species Most common marine ones are the
TURBELLARIANS- free living carnivores
www.daviddarling.info/images/flatworm_section.jpg
Polyclad flatworm, Pseudoceros sp, Egyptian Red Sea. Photo © Mike Keggen
http://www.julianrocks.net/flatworms/PseudobicerosBedfordi.html
FENCING
Flukes or TREMATODES- largest group of flatworms; 6000 species; all parasitic
Tapeworms or CESTODES- long body with repeating units; live in intestines of vertebrates; don’t have a gut or mouth but absorb nutrients
RIBBON WORMS
Or NEMERTEAN More complex organization Complete digestive tract with gut, mouth, and
anus Circulatory system Proboscis-long fleshy tube used to entangle
prey Predators that feed on worms and
crustaceans 900 species mostly marine
http://rydberg.biology.colostate.edu/Dissections/Nemertea/Nemerteawh.JPG
Nematodes
Roundworms Found mostly in sediment or intestinal tracts;
most parasitic; small, with slender body that is pointed at one end
Gut and anus Has a hydrostatic skeleton- a system that
uses water pressure against the body wall to maintain body shape and aid in locomotion
Anywhere between 10,000 to 25,000 species Larvae found in raw or poorly cooked fish
http://www.diplectanum.dsl.pipex.com/sim/anisak.jpg
SEGMENTED WORM OR ANNELIDS About 20,000 species More complex body systems Has segmentation- identical body segments Has a coelom-body cavity found in
structurally complex animals- completely surrounded by tissue developed from the mesoderm
Classes of Annelids
1)Polychaetes- most of the marine annelids;made of body segmetnns that have a pair of flattened extensions called parapodia that have setae (sharp bristles) Have a closed circulatory system that
transports nutrients, oxygen, and carbon dioxide
Have gills on the parapodia that contain capillaries to help with the absorption of oxygen
10,000 species almost all marine Live in temporary or permanent tubes made of
mucus, protein, seaweed bits, mud, etc. Mostly carnivores but some are suspension
feeders Proboscis ensnares prey
Life history of Polychaetes Have a trochophore- a planktonic larval stage
with cilia Some such as the Tomopteris are planktonic for
entire life
http://www.esu.edu/~milewski/intro_biol_two/lab__12_annel_arthro/images/nereis.jpg
Nereis
An assemblage of polychaetes (Photo by H. Torres)
2) Pogonophorans or beard worms- Lack a mouth and gut Has food absorbing tufts 135 species Deep water Another group called the vestimentiferans
are much longer Some found at hydrothermal vents
www.nematodes.org/.../pogonophora/pogo1.gif
3)Oligochaetes- found in mud and sand; eat detritus;marine relatives of earthworms; no parapodia
http://www.mpi-bremen.de/Binaries/Binary7687/Oalg_7_RGB_small.jpg
4.) Leeches- some marine species; parasitic; sucker at one end; no parapodia
Tracy Clark 8/11/2006
La Jolla ShoresHornyhead Tubot
Pleuronichthys verticalisLeech
UnidentifiedNikon D7060mm lens
PEANUT WORMS
Phylum: Sipuncula Unsegmented bodies Burrowers; shallow water; deposit feeders All marine Long, anterior portion has a mouth a a set of
small lobes of branching tentacles 320 species
http://www.livewild.org/CostaRica/Pics/a5751.jpg
ECHIURANS- phylum Echiura
135 species all marine Look like peanut worms but with a non-
retractable, spoon-like or forked proboscis Deposit feeders Some live in U-shaped tubes in the mud
http://farm4.static.flickr.com/3089/2922855838_a3df563b1e.jpg?v=1223412990
Molluscs: The Successful Soft Body
BASIC MOLLUSK CHARACTERISTICS Most have a soft body enclosed in a calcium
carbonate shell Body covered with a mantle- a thin layer of
tissue that secretes the shell Bilaterally symmetrical Ventral, muscular foot Head with sensory organs including eyes Have a radula- ribbon-like band of teeth
made of chitin used for feeding Have paired gills
3 major classes of Mollusks
Gastropods (class Gastropoda) Bivalves (class Bivalvia) Cephlapods (class Cephlapodia) 2 minor classes of Mollusks:
Chitons Tusk shells
Gastropods “stomach footed”
Largest and most common class Snails, limpets, abalones and nudibranches 75,000 species mostly marine Has a hard dorsal shell Use radula to scrape algae from rocks Some are deposit feeders; some are
carnivores Nudibranches or sea slugs have no shell
Nudibranch
http://birdhouse.org/blog/wp-content/uploads/2008/05/nudibranch.jpg
Limpet
www.barwonbluff.com.au/.../limpet%20smooth.jpg
limpet
www.theseashore.org.uk/theseashore
coneshell
http://www.scuba-equipment-usa.com/marine/JUN05/images/Conus_textile.jpg
Violet snails
http://www.floridastateparks.org/bahiahonda/images/BAH-violet-snail.jpg
BIVALVES
Clams,mussels,oysters etc. Body is laterally compressed and enclosed in
a shell with two parts No head, no radula Gills larger and used for obtaining oxygen
and to filter food particles Inner surface of shell lined by mantle;
therefore whole body is in the mantle cavity- a large space between the two halves of the mantle
Siphons-tube-like extension through which water flows in and out of the mantle cavity in bivalves, cephlapods, and tunicates
Mussels have byssal threads to attach to submerged surfaces such as rocks etc.
http://www.japan-hopper.com/wp-content/photos/pearl_oyster.jpg
Pearl oyster
Pearl diving video
www.waterworxbali.com/.../giant-clam-diver.jpg
Giant sea clam…largest bivalve can be up to 3ft in length
Some bivalves bore into coral, rock or wood Ex: shipworm– known as a fouling organism
because they settle on the bottom
CEPHLAPODA- “head-footed”
Predators Octopuses, squids, cuttlefishes Reduced or absent shell Foot modified into arms and tentacles with suckers Round bodies- octopus Elongated bodies- squid Bodies protected by thick, muscular mantle Mantle cavity behind head contains 2-4 gills Siphon = funnel- a muscular tube from the foot