Exercises 38a, 39, 40 Flashcards
Characteristics of Mollusca
1) Mantle that secretes shell (respiration/locomotion)
2) Visceral mass of organ systems (including an OPEN circulatory system)
3) Usually a calcium based shell
4) Sometimes a head
5) Always a ventral muscular foot
List the subdivisions of Mollusca
c. Polyplacophora (chiton)
c. Gastropoda (snail)
c. Bivalvia (oyster, clam, scallop, mussel)
c. Cephalopoda (octopus, squid, nautilus)
Describe c. Polyplacophora
1) Dorsal shell divided into eight plates embedded in mantle
2) Includes a toothed radula
3) Chitons (marine only)
Describe c. Gastropoda
1) Coiled shell
2) Includes a toothed radula
3) Snails
Describe c. Bivalvia
1) Two part dorsally hinged shell
2) Water flow: Incurrent siphon»_space;> gills for food filtering»_space;> mantle cavity»_space;> excurrent siphon
3) Labial palps direct food to mouth
4) Clams (Anodonta), oysters
Describe c. Cephalopoda
1) Shell is usually absent or reduced
2) Foot is modified into tentacles
3) They are predatory and have large sensory organs, like lensed eyes
4) Squid (Loligo), octopus, nautilus
Characteristics of Arthropoda
1) Rigid external skeleton, jointed appendages
2) Chitin exoskeleton
3) Segmented bodies
List the subdivisions of Arthropoda
1) sp.Chelicerata
2) sp.Crustacea
3) sp.Uniramia
Describe sp.Chelicerata
- Chelicerae, most anterior appendages modified into feeding structure
- Second pair pedipalps: predation
- TWO SEGMENTS: Cephalothorax and abdomen
- No antennae
- Uniramous
c.Merostomata
Horseshoe (Limulus)
Abdominal appendages are now book gills for gas exchange.
c.Arachnida
Spiders, scorpions, ticks
Eight legs, not fused segments
Describe sp. Crustacea
c.Crustacea
Crayfish, crabs (Cambarus), lobsters, shrimp
Unique with biramous appendages, think lobster pincer
TWO pairs of antennae, also compound eyes
Many appendages
Mandibulates
Describe sp. Uniramia
- Uniramous
- One pair of antennae
c. Chilopoda
Centipedes. Flat. Prey on small arthropods. One pair of legs per segment.
c. Diplopoda
Millipedes. Round. Prey on decaying stuff. Two pairs of legs per segment.
c. Insecta
Insects, Grasshoppers (Romalea). ENORMOUS GROUP
THREE body regions: Head, Thorax, Abdomen.
Wings are outgrowths of thoracic exoskeleton.
Tracheae conduct air through body
Characteristics of Echinodermata
- Marine bottom dwellers
- “Spiny skin”
- Have internal skeletons of calcareous plates, or ossicles
- Usually have spines
- Adults are radially symmetrical, larvae are bilaterally symmetrical
- Water vascular system. Inside the starfish are water-filled canals, connected to the madreporite and the tube feet. It uses muscle and hydrostatic pressure to move the tube feet.
List the subdivisions of Echinodermata
c. Asteroidea (sea star, starfish)
c. Ophiruoidea (brittle star)
c. Crinoidea (sea lilies, feather stars)
c. Echinoidea (sand dollars, sea urchins)
c. Holothuroidea (sea cucumbers)
Describe c.Asteroidea
- Sea stars (Asterias)
- Mouth on bottom (oral), anus on top (aboral)
- Spines include pincerlike pedicellariae for cleanup
- Water vascular system
Describe c.Ophiruoidea
- Brittle stars
- Ossicles are thick, attached musculature.
- Abulacral ridge has no ridge for tube feet