Chondrichthyes Flashcards
“What are Gnathostomes?
Jawed animals
“<b>What are 2 advantages of jaws?</b>”
Enhance foraging (biting off large chunks) & better manipulation
“<b>How doChondrichthyes squeeze gill arches together?</b>”
- bottom arch swivels to make chomping motion<br></br>- top arch remains attached to skull for stability
“<b>3 modes ofChondrichthyes reproduction?</b>”
oviparous, viviparous and ovoviviparous
“<b>Ovoviviparous<br></br></b><img></img><b><br></br></b>”
egg develop and hatch inside parent
“<b>Chondrichthyes are</b> monoceious/dioeceious <b>and reproduce via </b>internal/external<b> fertilizatoin?</b>”
Dioecious, Internal
“<b>What is the evolutionary purpose of a cartilaginous skeleton?</b>”
increase bouyancy
“<b>Subclass Elasmobranchii includes?</b>”
Sharks & Rays
“<b>DoSubclass Elasmobranchii have a notochord?</b>”
It is replaced by Vertebrae
“<b>What are the two stomach sections in Elasmobranchii?</b>”
cardiac and pyloric
“<b>What is the disadvantage of Elasmobranchii having a very short intestine?</b>”
limits nutrient absorbtion efficiency
“<b>Subclass Elasmobranchii have a Spiral valve use for?</b>”
large internal surface area<br></br>retain digestible material in ileum increase nutrient absorbtion
“<b>Elasmobranchii use a spiracle for</b>”
increase gas efficiency
“<b>Sharks swim to ___ the lungs,<br></br>While Rays _________</b>”
ventilate;<br></br><br></br>spiracles actively pump water over gills
“<b>Elasmobranchii have a 2 chambered heart. Divided into 1 ___ and 1 ____.</b>”
atrium<br></br>ventricle
“<b>The atrium and ventricle chambers in theElasmobranchiiheart is used for?</b>”
single circulation
“<b>Elasmobranchii have: (not well developed, excellent, limited)<br></br>___ hearing<br></br>___ vision<br></br>___ smell</b>”
not well developed, limited, excellent
“<b>What do the Ampullae of Lorenzinido?</b>”
sense electrical field of prey
“<b>Superorder Selachimorphabelongs to which Subclass?</b>”
Elasmobranchii
“<b>Superorder Selachimorpha include?</b>”
sharks
What does heterocercal mean?
“<b>Selachimorpha locomtion?</b>”
Paired fins for lift <br></br><br></br>Pectoral fins can’t swivel<br></br><br></br>fast speed but low maneuverability<br></br><br></br>Tail provides thrust and lift as shark moves through water<br></br><br></br>Head and fins flattened for lift during forward motion <br></br><br></br>Heavier than water: sink if they don’t continue swimming forward<br></br><br></br>Very fast sharks: modified tail fins for ↑ speed
“<b>Elasmobranchii have ___ bouyancy</b>”
negatively buoyant: sink if they stop swimming, heavoer than water<br></br><br></br>Expend more energy than if they were neutrally buoyant<br></br>
“<b>Placoid scales</b>”
Like small teeth and very tough <br></br><br></br>Flat rectangular base plate embedded in skin<br></br><br></br>Inner core of pulp composed of connective tissues, blood vessels and nerves <br></br><br></br>Pulp cavity treated by layer of odontoblast cells that secrete dentine <br></br><br></br>Covered with hard enamel outer layer<br></br><br></br>Secreted by cells in dermis <br></br><br></br>Pierce epidermis
Vertical – float vertically, using suction to draw prey in
Active – suction filter-feed while swimming, drawing water into mouths at higher velocities: “ram-filter feeding”
Oviparous: deposit eggs that hatch later: ""mermaid's purse“ - tough, leathery membrane; yolk feeds embryo. e.g., zebra shark
Ovoviviparous: eggs hatch internally but no placenta. e.g., cookiecutter shark"
- Benthic
Elarged winged pectoral fins
Move via wave like motion, lifiting and thrusting
respire: draw water into spiracles, force out gills,
5-6 gill slits on ventral surface
Tail, but the caudal fin reduced / absent
Small, blunt teeth in a plate used for grinding Dioecious: internal fertilization (♂ has claspers)
Elongated, soft bodies with a bulky head
One gill slit
Teeth fused to form plates
Lack placoid scales
Large pectoral fins and a long slender tail
No stomach
Benthic, often in very deep water
Move using sweeping movements of pectoral fins
Dorsal fin sometimes has a venomous erectile spine
Dioecious: internal fertilization, ♂ has claspers, ♀ oviparous
