Page 1
Form and Function: Fish (begin)
Marine Vertebrates: Lecture 1
Page 2
Challenges of the marine environment
•Density
•Pressure
•Temperature
Page 3
Temperature stratification
Page 4
Challenges of the marine environment
•Density
•Pressure
•Temperature
•Light
Page 5
Light attenuation with depth
Page 6
Challenges of the marine environment
•Density
•Pressure
•Temperature
•Light
•Salinity
•Oxygen
Page 8
Challenges of the marine environment• Density
• Pressure
• Temperature
• Light
• Salinity
• Oxygen
• Seasonality
• Substrate
Page 9
Vertebrate phylogeny
• Vertebrates are thought to be monophyletic, descended from a cephalochordate (or urochordate?) ancestor So ultimately, all marine vertebrates are
related
• However, the “marine vertebrates” themselves are polyphyletic, with various groups arising from fresh water or land-based ancestors at different times.
Page 11
Likely common ancestor to vertebrates: Phylum ChordataSubphylum Cephalochordata
• Invertebrate chordate = “lancelet”
• Larvae and adults have all chordate features (four shown plus endostyle = thyroid precursor)
• Muscles develop from somites: blocks of mesoderm (segmented)
Page 12
Subphylum Cephalochordata: lancelets
Page 13
Fish phylogeny: “Craniata”•Derived character: neural
crest cells/cranium
Neural crest/ cranium
Page 14
Neural crest (Craniata)
Page 15
Phylum Chordata, Subphylum Myxini: Hagfish
Campbell, Fig. 34.9
Page 16
Fish phylogeny: Phylum Chordata, Subphylum Vertebrata• Derived character: vertebral column
Vertebral column
Page 17
Subphylum Vertebrata;Class Cephalaspidomorphi
Page 18
Fish phylogeny: Phylum Chordata, Subphylum Vertebrata, “Gnathostomes”• Derived characters: jaws, bone,
paired fins
Jaws; Bone;
Paired fins
Page 19
Gnathostomes
• Jaw development From which structures?
•Development of bone Which structures were first
mineralized?
•Development of paired fins Hypothesis for origins?
Page 20
Class Chondrichthyes: Subclass Elasmobranchii
Page 21
Elasmobranchii: Features
• Skeleton Vertebral
column Cranium Teeth Upper jaw Ceratotrichia
• Nostrils
Page 22
Elasmobranchii: Features
Spiral valve within intestine:
Function?
Pelvic fins with claspers.
Function?
Page 23
Elasmobranchii: Features
•Gills
•Scales: placoid
•Buoyancy
Australian Museum of Natural History
Page 24
Circulation
Campbell, Biology
Page 25
Respiration: countercurrent exchange
Campbell, Biology
Page 26
Additional features
• Osmoregulation
• Reproduction Oviparity Ovoviviparity Viviparity
Page 29
Order Lamniformes: mackerel sharks Overview
Page 30
Focus: Family Lamnidae•Adaptations for effective
swimming Body shape (note snout!) Fins Ram ventilation Cruising speeds: ~3 km/h (great
white) Speed bursts: Up to 35 km/h (mako) Elevate body temperature
•Countercurrent heat exchange
Page 31
Countercurrent heat exchange: Great white shark
Page 32
The Behavior of White Sharks and their
Pinniped Prey during predatory attacks • Summary of research by Klimley,
Pyle and Anderson, 1996 (for next Monday!)
Deskpicture.com
Page 33
Order LamniformesFocus: basking sharks
Photos: D. Burton
Page 34
Order Charcharhiniformes Groundsharks: Overview
Photo: Paul Humann
Photo: Guillaume Chanfreau
Page 35
Order CharcharhiniformesFocus: Hammerheads
Photo: Guillaume Chanfreau
Page 36
Order CharcharhiniformesFocus: reef sharks (requim)
Page 37
Order Orectolobiformes Carpetsharks: Overview
Page 38
Order OrectolobiformesFocus: Wobbegongs
Page 39
Order OrectolobiformesFocus: Nurse sharks
Photos: Paul Humann
Page 40
Order OrectolobiformesFocus: Whale sharks
Photo: Werner Mischler
Page 41
Order HeterodontiformesBullhead sharks
Horn shark Photo: Tom Campbell, Innerspace VIsions
Page 42
Order Hexanchiformes
Photos: Michigan Science Art
Frill shark
Bluntnose sevengill shark
Page 43
Order SqualiformesDogfish sharks
Spiny dogfish Photo: J. Stafford-Deitsch
Page 44
Order SqualiformesCookie-cutter shark
Page 45
Order Pristiophoriformessawsharks
Page 46
Order SquatiniformesAngel sharks
Page 47
Skates and raysOverview
Photos: Paul Humann
Page 48
Order Rajiformes: skates
Page 49
Order Torpediniformeselectric rays
Page 50
Order Myliobatiformesbat rays, stingrays, manta rays
Photo: Andy Murch
Photo: Paul Humann
Page 51
Class ChondricthyesSubclass Holocephali