Download Phylum Annelida

Phylum Annelida
•Annelid- A round worm like animal that has a
segmented body
-Aquatic or land
-Segments are separated by internal walls
called septa (almost every segment looks
identical)
• Feeding
- long digestive tract
-mouth and anus
-have a pharynx
-have a crop (stores food) and a gizzard (grinds
the food)
Digestive System
• Respiration
-aquatic= gills
-land = cutaneous (diffusion through skin/cuticle)
• Internal Transport (closed circulatory system)
-two blood vessels
i.)dorsal blood (blood moves towards head
from anus PA)
ii.)ventral vessel (blood moves towards anus
from head A  P)
• Excretion
- solid undigested waste= anus (waste is called
castings)
-ammonia/metabolic waste = nephridia
• Response
- brain and ganglia
-nerve cord
**Most have:
-statocysts
-chemical receptors /sensory cells
eyes (light sensitive)
• Movement: two major muscle groups
1.) Longitudinal (run anterior/posterior)
-contract=shorter/longer
2.) Circular (around the body)
-contract = skinny/”fatter”
**Many have setae/bristles
• Reproduction:
-Sexual
-marine worms are separate gender (and
external fertilization)
-earthworms and leeches are hermaphrodites
(internal fertilization)
-contain a clitellum (mucus protection that
slides off and protects the fertilized eggs)
Three Different Classes
• Polychaetes
• Oligochaetes
• Hirudinea
• annelid summary video