Lecture 6. September 8, 2008

Finish Chondrichthyes

1. SHARKS & RAYSa. reproductionb. notable shark & ray ordersc. shark conservation

2. Sarcopterygii vs. Actinopterygii

3. Story of the coelacantha. Coelacanth biologyb. Lungfish biology

mermaid’s purses

Lemon Shark Giving Birth

• http://www.youtube.com/watch?v=LfQgRCg1bNA

Whale Shark

whale shark video

• http://www.youtube.com/watch?v=uQrBwN39LJI

goblin shark

megamouth

megamouth video

• http://www.youtube.com/watch?v=RxhqBmnZv8Q

• start at 2:10

thresher shark (Alopiidae)

thresher shark video

• http://www.youtube.com/watch?v=BQrrW9VRMFQ

• start at 5:30

basking sharks

great white shark

great white shark video

• http://www.youtube.com/watch?v=O2FInaOCqoo

Order Carcharhiniformes (ground sharks)

• Family Carcharhinidae (requiem sharks) Largest Order - 8 families, 210 species

Tiger shark Hammerhead shark

Order Carcharhiniformes (ground sharks)

• Family Carcharhinidae (requiem sharks)

Bull shark

Oceanic white tip shark

Silky shark

Shark attacks on humans

• 35 to 55 unprovoked attacks each year

• 6 to 11 fatalities per year

• 54% of attacks on surfers/windsurfers 38% on swimmers/waders 6% on divers/snorkelers

Regions with most shark attacks:

Shark attacks on humans

• 35 to 55 unprovoked attacks each year

• 6 to 11 fatalities per year

• 54% of attacks on surfers/windsurfers 38% on swimmers/waders 6% on divers/snorkelers

Regions with most shark attacks:South Africa - 63 attacks from 1990 to 2003Brazil - 57 “ “ “ “Australia - 51

Shark attacks on humans

• 35 to 55 unprovoked attacks each year

• 6 to 11 fatalities per year

• 54% of attacks on surfers/windsurfers 38% on swimmers/waders 6% on divers/snorkelers

Regions with most shark attacks:South Africa - 63 attacks from 1990 to 2003Brazil - 57 “ “ “ “Australia - 51Florida - 311

dogfish sharks (Squalidae)

dogfish shark

http://www.flmnh.ufl.edu/fish/sharks/SpinyDogfish/spinydogfish.html

saw sharks

pointed snout used to thrash and incapacitate small fishes

electric rays (Torpedinidae)

sawfish (Pristidae)

More sawfish pictures

Skates (Rajidae)

Myliobatiformes

Sting rays (Dasyatidae)

Myliobatiformes

Sting rays

Myliobatiformes

Manta rays (Myliobatidae)

Weblinks:

great white : http://www.flmnh.ufl.edu/fish/sharks/whaleshark/whaleshark.html

megamouth: http://www.flmnh.ufl.edu/fish/Sharks/Megamouth/mega.htm

thresher: http://www.new-brunswick.net/new-brunswick/sharks/species/thresher.html

hammerhead: http://www.flmnh.ufl.edu/fish/Gallery/Descript/SmHammer/SmoothHammerhead.html

sawfish: http://www.flmnh.ufl.edu/fish/education/sawfishbrochure.pdf

manta ray: http://www.flmnh.ufl.edu/fish/gallery/Descript/MantaRay/MantaRay.html

for ground and requiem sharks (family Carcharinidae), skates (family Rajidae), and sting rays (Dasyatidae) go to the following website and look up some details about one or two species.

http://www.flmnh.ufl.edu/fish/Education/bioprofile.htm

There is tons of really cool stuff on sharks at the Florida Museum of Natural History website.

We could spend a lot of time on each of the various orders and families in the Elasmobranchii. Instead, I want you to look up something about each of the following groups. Find one or two facts that are of interest to you.

shark conservation

soupfin sharksporbeagle

direct targets of fisheries - two examples

shark conservation

sharks as by-catch

Blue Shark - Common by-catch in swordfish fisheries

blue shark

swordfish

Discerning Characters of Sarcopterygii vs. Actinopterygii

• Fleshy, lobed pectoral, pelvic, anal and second dorsal fin

lobed, fleshy parts go up into fins

Class Sarcopterygii

• Three major living groups

• Coelacanthimorpha-coelacanths (two species)

• Dipnoi-lungfishes (six species)

• Tetrapoda (all non-fish vertebrates)

Order Coelacanthiformes

• Fossil record extends from M. Devonian (370 Ma) to Cretaceous (65Ma)

Order Coelacanthiformes

Marjorie Courtenay-Latimer

Order Coelacanthiformes

• Smith describes the coelacanth, Latimeria chalumnae, discovered in 1939, a true living fossil

Bony plates

Diphycercaltail

Teeth 0n hard

plates

Marjorie Courtenay-Latimer

Brass plate at Latimer's Landing East London.

Order Coelacanthiformes

• “New” populaiton discovered at Sulawesi, Indonesia 1997

Order Coelacanthiformes

• “New” populaiton discovered at Sulawesi, Indonesia 1997

• DNA analyses indicate divergence from L. chalumnae at 5.0-11.0 Ma

• Described as a new species L. menadoensis

Order Coelacanthiformes