Presentation Transcript
MOLLUSKS: MOLLUSKS 100,000 plus species
Live everywhere – ocean, streams, tree tops, etc.
Soft bodied animals
Have an internal or external shell
FORM & FUNCTION: FORM & FUNCTION 4 Basic Parts
Foot
Mouth/feeding parts
Mantle
Delicate tissue layer that covers most of body
Shell
Made by glands in mantle that secrete Calcium Carbonate
Visceral Mass
Contains the internal organs
FEEDING: FEEDING Every type found: herbivore, carnivore, omnivore, filter feeder, detritus feeder, and parasitic
Radula – think sandpaper
Snails and slugs
Tongue like structure with 100’s tiny teeth
Inside is a stiff rod of cartilage
Used to bring in food or drill through shell
FEEDING: FEEDING Octopi
Have radula and sharp jaws
Can poison their prey
Clams, Oysters, and Scallops
Filter feeders
Use gills and cilia to move food into the mouth
RESPIRATION: RESPIRATION Breath using their gills and in the mantle cavity
Have to keep the surface area moist, stay in/around water to breath
INTERNAL TRANSPORT: INTERNAL TRANSPORT Both open and closed circulatory systems
Snails and slugs – open circulatory system
Blood moves in vessels and sinus cavities
Not efficient, but slow moving so it works
Octopi – closed circulatory system
Blood moves in blood vessels
Faster moving
EXCRETION: EXCRETION Solid waste removal – Anus
Cell waste removal – Nephridia
Produce ammonia – poisonous to the mollusk
RESPONSE: RESPONSE Simple
Ganglia near mouth, few nerve cords, simple sense organs – balance, touch, chemical and eyespots
Complex
Brain, nervous system – see, touch, intelligence
Octopi
Can be reward/punish trained
REPRODUCTION: REPRODUCTION External Fertilization
Sexes are seperate
Release sperm and egg into the open water
Meet by chance
Internal Fertilization
Sexes separate or in same organisms
GASTROPODS: GASTROPODS Snail, slug, abalone, conch, etc.
Think shellfish
Means stomach foot
Both shell and shell-less
Shell for protection
Shell-less: bad tasting or poisonous
Bivalvia: Bivalvia Two-shelled mollusks
Clams, oysters, and scallops
Sessile
Burrow, stick to rocks
Can move by flapping their shells
Mantle glands
Make exterior shell
Release mother-of-pearl on inside of shell to keep it smooth: how a pearl is made
CEPHALOPODS: CEPHALOPODS Means head-foot – head is attached to the foot
Octopi, squid, cuttlefish, and nautiluses
Most have 8 tentacles with round sucking discs
Discs used to grab and hold prey
Bilateral body symmetry
Most have internal shell or no shell
Shell for protection
No shell can swim or crawl fast – use jet propulsion, release ink that has a foul taste to get away
CEPHALOPODS: CEPHALOPODS Most active Mollusk
Can change colors to adapt to their environment
Caused by chromatophore cells – special skin cells
MOLLUSK IMPACTS: MOLLUSK IMPACTS Feed on plants – slugs, snails
Prey on other animals
Clean-up surroundings by eating detritus
Filter feeders – environmental monitors
Pollutants become concentrated in tissues
Food source for people and other animals
May contain high amounts of pathogens, toxins, or pollutants – can cause sickness or death
MOLLUSKS IN ACTION: MOLLUSKS IN ACTION http://video.pbs.org:8080/ramgen/wnet/nature/octopus/sharkT1.rm White-lipped snail Leopard Slug, Somerville, MA Information courtesy of wikipedia.com, nova, marine bay, and pbs http://www.pbs.org/wgbh/nova/camo/ http://www.mbayaq.org/video/video_slippersnail_feeding_qt.asp
MOLLUSKS NOT IN ACTION: MOLLUSKS NOT IN ACTION Oyster Sauce Octopuses at Tsukiji fish market Fried calamari:
breaded, deep-fried squid.
MONDAY - CLAM: MONDAY - CLAM CLAM
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia