Annelids

earthworms phylum

annelidia

annelids, clams and octopi all share similar...

larval stages

septum

internal walls between segments

setae

little bristles attached to each annelid segment

annelids are among the simplest animals to have a true...

coelom

how is the pharynx used differently in carnivorous species than annelids that feed on decaying vegetation?

the pharynx usually holds 2 or more sharp jaws that are used to attack prey. it extends its pharynx and presses it against surrounding sediments.

closed circulatory system

blood is contained within a network of blood vessels

gill

a filamentous organ specialized for the exchange of gases underwater.

how do aquatic annelids respire differently than land dwelling annelids?

aquatic annelids breathe through gills, land dwelling annelids breathe through their skin.

how do annelids keep their skin moist?

they secrete a thin protective coating of mucus

the two groups of annelid body muscles are called

longitudinal and circular muscles

marine annelids have paddle-like appendages called

parapodia

clitellum

a band of thickened specialized segments secretes a mucus ring into which eggs and sperm are released

earthworms

long, pinkish brown worms with few setae found in woods, fields and gardens

tubifex worms

red, threadlike worms with few setae, found in aquatic areas

leeches

suck blood and body fluids from their hosts, most live in moist and tropical habitats, and they are typically external parasites

what annelids do polychaetes include?

marine annelids, such as sandworms and bloodworms

polychaetes

they have paired, paddlelike appendages tipped with setae and are marine annelids

how do tunnels of earthworms affect other organisms?

they benefit plant life and allow the growth of beneficial oxygen requiring soil bacteria

annelid

earthworms are important to the diet of birds, they bring minerals from deep soil layers to the surface and larvae form part of the animal plankton

segmented worms

coelomates, first hole becomes the mouth, same embryonic development as nematodes

three classes of annelids (hermaphroditic)

oligocheates (earthworms), polycheates (fanworms, tubeworms, pileworms) and hirudinea (leeches)

can earthworms move backwards?

no, setae doesn't allow it

sperm duct / oviduct opening

located on the ventral side of the worm and releases sperm/egg

sperm receptacle opening

takes in the sperm

which direction does blood flow in earthworms?

from anterior to posterior

in an earthworm, the external opening closest to the clitellum is the?

mouth

a structure that helps the earthworm move is?

setae

in an earthworm, almost all segments contain openings associated with the...

reproductive system

during the process of reproduction, the clitellum of an earthworm...

forms a mucous ring

the prostomium is closest to the...

mouth

the presence of sperm receptacle openings and oviduct openings in an individual earthworm indicates that the worm...

is a hermaphrodite

earthworms help maintain the quality of soil by...

aerating the soil

moist soil enables the earthworm to...

breathe

the openings of the sperm ducts of an earthworm are located ventrally on the segment numbered...

15

the sperm receptacle opening of an earthworm are located between segments...

9-10-11

gizzard

grinds the food

crop

stores the food

intestine

digests the food

nephridium

used to get rid of nitrogenous wastes

why is the earthworm body referred to as a tube within a tube?

because they are segmented worms with two layers and aseptrum

how does the earthworm obtain oxygen and eliminate carbon dioxide?

they breathe through their skin