5/18/2012 1 BIO202 - 2012 Scharf BIO202 - 2012 Scharf About 1000 species Unchanged in last 200 MY Nearly all marine Shark populations threatened Vertebrates Living Gnathostomes (jawed fishes) Cartilaginous fishes (Class Chondrichthyes) BIO202 - 2012 Scharf No bone (calcified cartilage) Heterocercal tail Paired pectoral and pelvic fins Pelvic claspers in males Placoid scales Vertebrates Living Gnathostomes (jawed fishes) Cartilaginous fishes (Class Chondrichthyes)
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14. Chondrichthyes and Teleosts - 202.pptpeople.uncw.edu/scharff/courses/202/pdfs/14. Chondrichthyes and... · Reproduction in Chondrichthyes. 5/18/2012 4 BIO202 - 2012 Scharf
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5/18/2012
1
BIO202 - 2012 Scharf
BIO202 - 2012 Scharf
About 1000 species
Unchanged in last 200 MY
Nearly all marine
Shark populations threatened
Vertebrates
Living Gnathostomes (jawed fishes)Cartilaginous fishes
(Class Chondrichthyes)
BIO202 - 2012 Scharf
No bone (calcified cartilage)
Heterocercal tail
Paired pectoral and pelvic fins
Pelvic claspers in males
Placoid scales
Vertebrates
Living Gnathostomes (jawed fishes)Cartilaginous fishes
(Class Chondrichthyes)
5/18/2012
2
BIO202 - 2012 Scharf
Exposed gill slits
No swim bladder
Retain high urea concentrations
Well-developed senses
Vertebrates
Living Gnathostomes (jawed fishes)Cartilaginous fishes
(Class Chondrichthyes)
BIO202 - 2012 Scharf
BIO202 - 2012 Scharf
Mostly carnivores
Olfactory organs
Mechanoreception with lateral line
Good vision
Attacks fine-tuned with electroreceptors
Vertebrates
Feeding in Chondrichthyes
5/18/2012
3
BIO202 - 2012 Scharf
BIO202 - 2012 Scharf
BIO202 - 2012 Scharf
Internal fertilization
Types of maternal investment:
1. Oviparity
2. Ovoviviparity
3. Viviparity
Intrauterine cannabalism “oophagy”
Vertebrates
Reproduction in Chondrichthyes
5/18/2012
4
BIO202 - 2012 Scharf
Dorsoventrally flattened
Large, fused pectoral fins
Dorsal spiracles for water intake
Pavement-like crushing teeth
Skates lay eggs in leathery case “mermaid’s purse”