Bellwork – name and state the
function of each organ
Digestion and Evolutionary Adaptions
Suspension Feeders
 Many aquatic animals are suspension feeders, which sift
small food particles from the water
Substrate Feeders
 Substrate feeders are animals that live in or on their
food source
Fluid Feeders
 Fluid feeders suck nutrient-rich fluid from a living host
Bulk Feeders
 Bulk feeders eat relatively large pieces of food
 Animals with simple body plans have a gastrovascular
cavity that functions in both digestion and distribution of
nutrients
Video: Hydra Eating Daphnia
Fig. 41-9
More complex
animals have a
digestive tube
with two
openings, a
mouth and an
anus
Crop
Gizzard
Intestine
Esophagus
Pharynx
Anus
Mouth
Typhlosole
Lumen of intestine
(a) Earthworm
Foregut
Midgut
Hindgut
Esophagus
Rectum
Anus
Crop
Mouth
Gastric cecae
(b) Grasshopper
Stomach
Gizzard
Intestine
Mouth
Esophagus
Crop
Anus
(c) Bird
This digestive
tube is called an
alimentary canal
Some Dental Adaptations
 Dentition, an animal’s
assortment of teeth, is
one example of
structural variation
reflecting diet
 dentition is adapted to
their usual diet
Why might this have evolved?
 Hint: the cecum has
bacteria that breaks
down plant material
Fig. 41-20
1
Rumen
2
Reticulum
Intestine
Esophagus
4
Abomasum
3
Omasum