Major Body Functions in Invertebrates

1
Major Body Functions in Invertebrates
(Feeding, Respiration,Circulation and Excretion)
2
What are we talking about?

• Respiration - get O2 into body
• Circulation (or transport) move O2 and
  nutrients around to tissues and remove CO2 and
  other wastes from tissues
• Excretion - removal of wastes (urea and ammonia)
  from body

3
Porifera (Sponges)
Movement of H2O through the sponge provides
a simple mechanism to carry out all body
functions

• Filter feeders, intracellular digestion
• Symbiotic PSN bacteria, algae and protists
  provide addl food
• and O2
• Wastes diffuse through cell membranes, carried
  away by H2O

4
Cnidaria
(Sea jellies, sea anemones, corals, hydras)

• FEEDING
• Paralyze prey w/nematocysts and use tentacles to
  pull prey
• through mouth into g.v. cavity
• Corals have symbiotic PSN algae that provide
  nutrients and O2
• during the day
• At night, carnivorous!

• TRANSPORT, RESPIRATION AND EXCRETION
• Via diffusion through body walls

5
Flatworms
Specialized tissues and organ systems that are
more complex in free-living than in parasitic
species
FEEDING

• Carnivores
• Scavengers
• Parasitic flatworms
• Have simplified or lost many organ systems
• Pharynx sucks food into . . .
• Digestive cavity
• Intracellular digestion

Tapeworms have no digestive system -- nuf said?
6
Flatworms (contd)

• RESPIRATION and CIRCULATION
• No gills, lungs heart, blood
• Diffusion sufficient since they are so thin

• EXCRETION first specialized tissues!
• Free-living flatworms use flame cells
• to filter and remove urea, ammonia
• and excess H2O

7
Roundworms
Specialized tissues and organ systems that are
more complex in free-living than in parasitic
species

• FEEDING
• Parasitic
• Free-living predators
• Grasping mouth parts and spines to catch small
  animal prey
• Free-living scavengers

RESPIRATION, CIRCULATION AND EXCRETION Like
flatworms, diffusion is sufficient
8
Annelida
First organ systems!

• FEEDING
• Filter feeders
• Predators
• Pharynx which may have teeth
• Detritovores/deposit feeders
• Muscular pharynx pumps food into
• Esophogus to crop (storage) and
• Gizzard (grinds) to the
• Intestine (nutrients are absorbed)

Crop/Gizzard
Intestine
Pharynx
9
Annelida

• CIRCULATION
• Closed circulatory system
• Two major blood vessels, dorsal and ventral
• Lateral hearts

• RESPIRATION
• Aquatic gills
• Terrestrial diffusion through skin
• (must stay moist)

• EXCRETION
• Solid wastes pass out the anus
• Nitrogenous wastes eliminated by nephridia which
  filter
• fluid (think kidney) in the coelom

10
Phylum Mollusca
Class Gastropoda - snails, slugs

• FEEDING
• Herbivores - scrape algae off rock
• Carnivores - drill through shells of other
  mollusks
• Detritivores - detritus!
• Use a radula (flexible, tongue-like w/tiny
  teeth)

• EXCRETION
• Tube-shaped nephridia

11
Mollusca
(Class Gastropods)
RESPIRATION

• gills - aquatic
• diffusion through mantle - terrestrial

• TRANSPORT
• Open circulatory system
• Heart, blood vessels, sinuses to gills

• where O2 and CO2 are exchanged
• Sinuses tissues are bathed in blood
• rather than blood staying in blood vessels
• (sprinkler system)

12
Phylum Mollusca
Class Bivalves

• FEEDING
• Cilia on gills pull H2O in through siphon
• Mucus and cilia trap food particles
• Sand, etc. expelled through siphon

Clam gill

• EXCRETION
• Anus
• Nephridia

RESPIRATION Gills
TRANSPORT Open Circulatory System
13
Mollusca
Class Cephalopoda - octopus, squid,
cuttlefish nautilus
Most complex of animals so far
FEEDING 8 or more tentacles with suction cups
to grasp prey Nautilus can have up to 90
tentacles! Sharp jaws or beaks Some octopi have
poison to subdue prey
14
Mollusca
Cephalopods
RESPIRATION AND EXCRETION same as other mollusks
CIRCULATION/TRANSPORT Closed circulatory system
(the only molluscs w/ closed) greater O2
capabilities greater access to energy
15
PHYLUM ARTHROPODA

• Includes the Classes Crustacea, Arachnida
• and Insecta

16
PHYLUM ARTHROPODA (Class Crusatacea)

• FEEDING
• Omnivores
• 2 sets of antennae
• 3 pairs of head appendages
• Mandibles grinding mouthparts (like jaws but
  move
• side-to-side not up-down), maxillae
• Chelipeds claws to catch, crush, cut, handle
• food

17
PHYLUM ARTHROPODA (Class Crusatacea)

• RESPIRATION
• Gills - aquatic
• Tracheal Tubes - land
• CIRCULATION
• Open-Circulatory System

• EXCRETION
• Green gland or antennal gland,
• anus

18
PHYLUM ARTHROPODA (Class Arachnida)

• Feeding carnivores
• Mouthparts
• Chelicerae (fangs) to stab and paralyze prey
• Pedipalps handle prey, digested out of body
• Circulation Open-Circulatory System

• RESPIRATION
• Book lungs
• EXCRETION
• Malpighian tubes (terrestrial)

19
PHYLUM ARTHROPODA (Class Insecta)
Ants, termites, beetles, butterflies, fleas,
weevils, cockroaches, etc.

• Feeding carnivores, herbivores
• Mouthparts highly specialized
• Mandibles for grinding similar to crustacea
• Saliva w/ digestive enzymes
• Butterflies, moths proboscis
• mosquito- straw
• fly - sponge
• Circulation Open Circulatory System

20
PHYLUM ARTHROPODA (Class Insecta)

• RESPIRATION
• Tracheal Tubes
• network of tiny tubes
• throughout body allows
• each cell to get O2 directly -- blood is not red!
• EXCRETION
• Malpighian tubes

21
PHYLUM ECHINODERMATA

• FEEDING
• Herbivores, Carnivores, Detritovores
• Sea urchins - Aristotles lantern (five part
  jawlike structure) to scrape algae from coral,
  rocks
• Sea stars - tube feet and water vascular
• system, pry open bivalves, extrude stomach,
  digest prey w/enzymes and pull it
• all back in

22
PHYLUM ECHINODERMATA

• FEEDING
• Herbivores, Carnivores, Detritovores
• Sea cucumber - Puts out tentacles, collects
• small particles, licks its fingers, also
  grazing
• detritovores

23
PHYLUM ECHINODERMATA

• TRANSPORT
• Water vascular system - madreporite
• Skin gills

• RESPIRATION AND EXCRETION
• Diffusion thru the thin-walled tube feet
• Solid waste through anus

24
(No Transcript)