Kinds of Feeders

Question 1

What are the types of feeding behaviours?

Answer 1

Hunters, parasites, grazers and browsers, suspension feeders, deposit feeders. Organisms can belong to more than one feeding group. Feeding behaviours are rarely confined to one clade because of convergent evolution.

Question 2

What is phagocytosis?

Answer 2

Process where cells engulf solid particles to form an internal food vacuole or phagosome. Involved in acquisition of nutrients and the immune system.

Question 3

Who does phagocytosis for feeding?

Answer 3

Protozoa

Question 4

What is protozoa?

Answer 4

Single celled eukaryotes.

Question 5

What is a ciliate?

Answer 5

complex unicellular organisms with 2 types of nuclei and an elaborate pellicle and associated ciliature.

Question 6

what is a cytostome?

Answer 6

ciliates have them, they are a well-defined permanent mouth that occupies a fixed location where food vacuoles are formed.

Question 7

What is the oral groove?

Answer 7

Found in paramecium, cilia sweeps prey into oral groove, where food vacuoles form in cytopharynx

Question 8

Passage of food vacuoles in paramecium

Answer 8

Forms in cytopharynx, move in circuitous route through the cell while various events of digestion occur.
Goes from highly acidic to pH 5, where digestion occurs.
Eventually arrives at fixed cytoproct (cell anus) posterior to cytostome.

Question 9

How do filter / suspension feeders feed?

Answer 9

By straining suspended matter and food particles from the water. Pass water over specialized sieve-like structure

Question 10

What groups of invertebrates use suspension / filter feeding?

Answer 10

Poriferans, polychaetes, barnacles, crustaceans, tunicates, cephalochordates, clams, corals, bryozoans

Question 11

Examples of structures used by filter/suspension feeders to eat:

Answer 11

slitted pharynx, whorl of tentacles, finely fringed limbs, ciliated gills, mucous sheets.

Question 12

How do filter/suspension feeders use their cilia?

Answer 12

Beating cilia create a current that passes over/through the body. Combine with mucous to create a trap, sort and transport the food particles. Food adheres to mucous which is then shifted by cilia to digestion locations.

Question 13

Who would have a U-shaped gut?

Answer 13

Tube dwelling organisms and many sedentary deposit feeders.

Question 14

What is a euphasid?

Answer 14

Krill

Question 15

What kind of feeders are euphasids?

Answer 15

AKA Krill, they are suspension feeders

Question 16

How do euphasids feed?

Answer 16

Suspension feeders. Endopods form a funnel shaped feeding basket below the thorax.

Question 17

How do euphasids use their feeding basket?

Answer 17

Endopods are extended down and out, enclose a parcel of water. Then they retract and squeeze the water through a small setal filter. Food particles get trapped inside.

Question 18

How do crayfish feed?

Answer 18

suspension feeding, use their stomachs to press food out of suspension.

Question 19

Crayfish stomach

Answer 19

Large, thin-walled, translucent sac. Located directly above mouth. 2 chambers - cardiac stomach and pyloric stomach.

Question 20

Crayfish mandibular adductors

Answer 20

2 large muscles at lateral end of stomach

Question 21

what is the function of the Crayfish cardiac stomach

Answer 21

It contains the gastric mill - series of calcareous plates and teeth that grind, mix, and regrind the food.

Question 22

What is the function of the crayfish pyloric stomach?

Answer 22

Filters food from the gastric mill using the filter press.

Question 23

What are gastroliths?

Answer 23

Part of crayfish. 2 large, oval, calcified areas on the anterolateral walls of the cardiac stomach. Calcium is secreted here prior to each moult.

Question 24

Other examples of filter feeders from the lab

Answer 24

Mole crabs and fan worms