Phyla Annelida Flashcards
hydrostatic skeleton
muscles working in conjunction with water pressure
setae
bristles four on the body segments
crop
food storage area found in annelids
gizzard
digestive organ for grinding food prior to absorption
clitellum
reproductive structure found on outside of earthworm
ventral vessel
blood vessel located on underside of earthworm
arotic arches
hearts of earthworms
annelids
segmented worms
nephridia
excretory organs that filter fluid of nitrogenous wastes in coelom
phylum annelida
refers to “little ring” and worms body segments. segmented separated by septa - internal walls between. segments may have specialized functions. sensory - eyes, respiration, many annelids have setae on segments bristles. have true coelom.
feeding and digestion
range from filter feeders to predators. carnivores pieces, nereis, have sharp jaws in pharynx. detritivores have mucus in pharynx. earthworms pump food and soil into esophagus - crop (food storage) - gizzard (grind food) - digestive tract for absorption.
circulation
closed circulatory system, blood contained in a network of blood vessels. BLOOD NEVER LEAVES THE VESSELS
respiration
aquatic annelids have gills. earthworms diffuse gases through moist skin.
excretion
waste exits body through the anus. nitrogenous wastes in cells removed through nephridia, excretory organs that filter fluid in coelom.
response
well-developed nervous system with brain and several nerve cord. variety of adaptions for detecting stimuli: sensory tentacles, chemical receptors. statocysts to detect gravity and two or more pairs of eyes.
movement
longitudinal muscles and circular muscles for hubristic skeleton. marine annelids have parapodia - paddle-like appendages for crawling and swimming.
reproduction
sexual reproduction, external or internal fertilization depending on species others are hermaphoditic. some have self-fertilization.
class oligochaete
earthworms and relatives, streamlined bodies, few setae. live in soil or fresh water.
class hirudinea
contains ledges, external parasites that suck blood and body fluids from host. approximately 1/4 of leeches are carnivorous feeding on small invertebrates. powerful suckers.
ecology of annelids
earthworms aerate soil, loosen soil for plant growth. decomposers and prey animals for birds, reptiles and fish.
pharynx
muscular tube connecting the mouth to the esophagus