segmented worms. diversity live in all parts of the world (except arctic and antarctic regions) can...
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DiversityLive in all parts of the world (except Arctic and
antarctic regions)Can be marine, freshwater, or terrestrial
Approximately 9,000 speciesRange in size from 1mm- 11 Feet
Common Earthworm is 9-10 inchesKnown as segmented wormsEx: leech, earthworm
Characteristics of All AnnelidsBody System: Tube within a tube
Inner tube is the straight line digestive tractExtends from mouth (first segment) to anus (last
segment)Outer tube consists of two layers of muscle, moist
skin, a cuticle, and secretion of slimy mucousFluid filled cavity between the two tubes
Contains a well developed circulatory systemNervous systemThread like kidneysReproductive organs
Characteristics of All AnnelidsBilateral SymmetryMetamerism (segmentation)
Increases the efficiency of body movementAllows for greater complexity of the body
systemsMuscular Structure
Both longitudinal and circular musclesSurrounded by moist cuticle (outer covering)
which aids in breathing
Characteristics of All AnnelidsSetae
Used for locomotionLeeches do not have these
Coelom is well developedCirculatory system is closedDigestive System is completeRespiratory System
Gas exchange occurs through skin, gills, or parapodia
Characteristics of All AnnelidsExcretory system
A pair of nephridiaNervous System
Double ventral nerve cord and pair of gangliaSensory System
Taste buds, photoreceptor cells and eyed with lenses (in most)
Reproductive SystemHermaphroditic or separate sexesMay have asexual reproduction
ClassificationKingdom Animalia
Phylum AnnelidaClass Oligochaeta
Examples: EarthwormsClass Polychaeta – means many bristles
Examples: lugworms, clam worms, bristlewormsApproximately 8,000 species
Class HirudineaExamples: leechesOften used in medicine to relieve swollen limbs, dry
skin, etc.
Worm compostingRecycling the organic waste of a household into compost
allows us to return badly needed organic matter to the soil
Worm composting is a method for recycling food waste into a rich, dark, earth-smelling soil conditioner.
Worm compost is made in a container filled with moistened bedding and redworms
Add your food waste for a period of time, and the worms and micro-organisms will eventually convert the entire contents into rich compost.
Composting DIY
Class OligochaetaEarthworms:• Burrow in soil• Come out at night to explore• Can drown if soil gets too wet• Diet: scavengers (eat dead,
decaying matter)• Have the ability to learn!
Class PolychaetaPolychaetes:• Ex: Christmas tree worm,
Fireworm, Scaleworm• Largest group of annelids• Mostly marine• Brightly colored or can be
dull in color
Class HirudineaLeeches:• Live mostly in freshwater• More abundant in tropical
areas• Most are carnivorous
(feed on meat, blood)• Have two brains!
Characteristics of Earthworm (most “famous” of Annelids)
Soil is natural habitatBurrows head first into soil (makes its burrow by
using the pointed head end to push soil aside)Eats soil for food (obtains nutrients/water from the
soil)Can feed on grass, leaf/scraps of organic matter
Also digest humus (dead, decaying matter)Head end is light-sensitive
Nocturnal—feed/eat/active during nighttime
Long, slender body (cylindrical)150-200 ring-like segmentsLocomotion/movement—performed by layers of
muscle in the body wall (circular bands of muscle)Ventral (belly) side has setae (bristle-like hairs) used
for movementMature worms have a clitellum (produces the egg capsule
at breeding time)—larger segment (lighter in color)Respiration—through its moist skin (cannot become dry
—worm would suffocate)
Characteristics of Earthworm (most “famous” of Annelids)
Organs:Pharynx—sucks in food (think of a vacuum)Esophagus—food enters here once enters mouthCrop—temporary storage (from esophagus)Gizzard—grinds food into small piecesIntestines—digestion and absorption occur hereAortic arches—-part of closed circulatory system,
contains 5 of these, maintains a steady pressure of blood to vessels
Ganglia—nervous system organ, brain
Characteristics of Earthworm (most “famous” of Annelids)
Nerve cord—runs from ganglia to each segment, provides nerves to body structures
Blood vessel—part of closed circulatory system, moves oxygen throughout body
Clitellum—reproductive organ, secretes mucus, stores eggs/sperm during reproduction
Setae—movement and reproductive purposesSegments—mouth-anus sensory/excretory organs are
attached to muscle wall of each segment Anus--excretionNephridium—excretory organ, excrete ammonia
Characteristics of Earthworm (most “famous” of Annelids)
Other/Biosphere/UsesHelp to aerate the soilPrepare soil with nutrients from excretory waste
productsLeeches can be used for medicinal purposes (for
blood clotting issues)Earthworms: eat, fishing, aerate soil, etc
Characteristics of Earthworm (most “famous” of Annelids)