Annelida, Arthropoda, Echinodermata

Question 0

Classes of Annelida

Answer 0

Polychaeta (nereis)
• #s of slender bristles (setae) on
parapodia (for loco & respiration)

Oligochaeta (earthworm)
• fewer setae
• clitellum (reproduction)
• 2 Muscle layers (circ & long)
• Hermaphroditic
• Skin for gas exchange
• Hydrostatic skeleton
• (Meta)nephridia each seg (excretion)
• Thyphlosole fold in dorsal wall of 
  intest to inc surf area for absorption

Hirudinea (leeches)
• Lack septae
• Suckers
•.Clitellum

Question 1

Phylum Annelida

Answer 1

• Triplioblastic
• Protostome
• Coelomate
• Ventral nerve cord
• Segmented worms
    – Ringed appearance= internal 
       segments
• Closed circulation
• Locomotion:
     – Circular & longitude muscles work 
        against fluid-filled coelom for 
        movement
• Specialized digestive system
     – Crop & gizzard

Question 2

Phylum Arthropoda

Answer 2

Joint footed animals

• Triplioblastic
• Protostome
• Coelomate,
• Segmentation
• Special appendages
• Paired, jointed appendages
• Chotinous hard exoskeleton

Question 3

Subphylum Chelicerata

Phylum Arthropoda

Answer 3

• Body regions: cephalothorax &
abdomen

• Class Xiphosura: 
     – Horseshoe crab
• Class Arachnida:
     – Spiders, scorpions, ticks, mites
           • 4 Pairs of walking legs

Question 4

Subphylum Crustacea

Phylum Arthropoda

Answer 4

Class Crustacea
• Crab, shrimp, crayfish, lobster

• carapace
• cephalothorax
    – Head & thorax fused together
• abdominal segments
• Appendages surround mouth: feeding
• Well developed digestive tract
• Dorsel, posterior, & anterior arteries 
   carry hemolymph (blood & lymph to 
   tissue cavities
• Green glands
• 3-5 pairs of legs
• gills
• Swimmerets (male has 2 pr claspers 
   instead of reg swimmerets)
• uropods & telson
• 2 pairs of antennae
• Ventral nerve cord

Question 5

Subphylum Uniramia

Phylum Arthropoda

Answer 5

• Breathe by trachea
• 3 pairs of legs
• 2 pairs antennae

Class Chilopoda (centipedes)
Class Diplopoda (millipedes)
Class Insecta/Hexapoda (honeybees)
• Largest # individuals in animal king

Question 6

Grasshopper
(Phylum Arthropoda
Subphylum Uniramia
Class Insecta)

Answer 6

• Head
• Thorax
• Abdomen
• Brain (inhibitory)
• Segmental ganglia
• Ventral nerve cord
• 2 types of eyes (comp & simple)
• 3 pairs of legs
• 2 prs chitin wings attach to thorax
• Spiracles on outside of body open 
   into tracheal tubes
• Crop
• Stomach
• Intestine
• Gastric ceca
• Excrete by malpghian tubules 
   emptying into intestine to conserve 
   water
• Incomplete metamorphosis
    – egg > nymps > adults

Question 7

Phylum Echinodermata

Answer 7

Spiny skinned animals
• Deuterostome
• Spines from endoskeleton made of 
   calcium carbonate plates
• Most have defensive spines on outer 
   skin
• Adult radial symmetry (Larvae usually 
   bilateral)
• Water vascular system (unique)
     – Tube feet for loco, gas exch, or 
        food gathering

• Class Astroidea (starfish)
• Class Echinoidea (sea urchins,sand $)
• Class Ophiuroidea (brittle stars)
• Class Holothuroidea (sea cucumber)

Question 8

Class Astroidea

Phylum Echinodermata

Answer 8

Starfish

• stone canal
• ring canal
• Radial canal
• tube feet on bottom
• madreporite (sieve plate)
• digestive glands & gonads in arms
• 5 arms radiate around central disc
• Mouse oriented downward