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
Describe c.Crinoidea
- Feather stars and sea lilies
- Highly branched, feathery arms, well developed ossicles
- Mouth and anus both face up
Describe c.Echinoidea
- Sea Urchins, Sand dollars
- Ossicles are fused into a solid shell, or test
- Very prominent spines, which are movable and jointed
- Holes in test allow for long tube feet
Describe c.Holothuroidea
- Sea cucumbers
- Mouth is surrounded by modified tube feet, tentacles
- Soft bodies, very reduced ossicles and spines
Characteristics of Chordata
- Dorsal Hollow Nerve Chord (on top of notochord)
- Notochord (cartilagenous rod)
- Postanal tail
- Pharyngeal slits (filter water, becomes gills)
- Internal, bony skeleton is common
List the subdivisions of Chordata
sp. Urochordata
sp. Cephalocordata
sp. Vertebrata
Describe sp.Urochordata
- Tunicates or sea squirt
- Sessile.
- Larvae are chordate-like with notochord and dorsal nerve cord
- Adults look like a shirt (w/ cellulose shirt sac) and have pharyngeal slits
- Adult filter feeds through incurrent and excurrent siphons
Describe sp.Cephalochordata
- Lancelets
- Have notochord and dorsal nerve chord on top
- Have gill openings separated by gill arches
- Postanal tail
- The quintessential Chordate :)
Describe sp.Vertebrata. Just the aquatic animals.
- Vertebral column instead of notochord; surrounds the nerve cord.
- Have a distinct head
c.Agnatha
Lampreys, hagfish (Petromyzon). Larval form is ammocoete. No jaws, but they have notochord and endoskeleton
Round buccal funnel, suction with teeth and rasping tongue
c.Chondrichthyes
Sharks, skates, rays. Cartilagenous endoskeleton. Anterior gill arches modified into Jaws the Movie. Pectoral fins are on the sides, pelvic at the end, both stabilize and help maneuver. Has lateral line and lots of other sensory organs.
c.Osteichthyes
Fish. Bony endoskeleton. Also have modified gill arches. Operculum is movable gill cover. Also has lateral line sensory organs. Have internal air bladders for buoyancy.
Describe sp.Vertebrata. Just the terrestrial animals.
c.Amphibia
Terrestrial mostly, but lay eggs in water. Larva are tadpoles. Have soft moist skin for gas exchange.
c.Reptilia
Can internally fertilize. Lays watertight eggs. Dry skin with scales to avoid water loss. Well-developed lungs (internal gas exchange). Ectotherms.
- Chorion: outside film of egg. Watertight, but permeable to gases.
- Allantois: waste; Yolk sac: food; Amnion: baby
c.Aves
Has feathers and great vision. Endothermic. Contour feathers, lightweight, efficient respiration, muscled breasts for flight.
c.Mammalia
Has insulating body fat and hair to help with temperature; endotherms. Well developed circulatory system with 4 chambered heart. Has mammary glands.
Protosomes vs. Deuterosomes
Protosomes - Mollusca and Arthropoda - Blastopore opening becomes mouth - Spiral, determinate cleavage Deuterosomes - Echinodermata and Chordata - Blastopore opening becomes anus - Random, indeterminate cleavage
