1. Lecture 7. September 10, 2008
1. Shark Conservation
2. Actinopterygii vs. Sarcopterygii
3. Coelacanth story.
4. Details on Coelacanth & Lungfishes

2. Fish in the News!

3. shark conservation direct targets of fisheries - two examples
porbeagle
soupfin sharks

4. shark conservation
sharks as by-catch

5. Blue Shark - Common by-catch in swordfish fisheries

6. Discerning Characters of Sarcopterygii vs. Actinopterygii

7. Fleshy, lobed pectoral, pelvic, anal and second dorsal fin
Fins can rotate 180 degrees
lobed, fleshy parts go up into fins

8. Bony leg-like supports, external to body
Class Sarcopterygii
Lobe fins
Bony leg-like supports, external to body
Pectoral fin
Pelvic fin

11. Class Sarcopterygii
Three major living groups
Coelacanthimorpha-coelacanths (two species)
Dipnoi-lungfishes (six species)
Tetrapoda (all non-fish vertebrates)

12. Class Sarcopterygii Osteolepimorpha - extinct Coelacanthimorpha
Tetrapoda
Dipnoi

13. Order Coelacanthiformes
Fossil record extends from M. Devonian (370 Ma) to Cretaceous (65Ma)
This 65 ma date is noteworthy, because for a long, long time it was believed that this group of fishes died out - about the same time dinosaurs disappeared
However, in 1937…..

14. Order Coelacanthiformes
Marjorie Courtenay-Latimer
In 1938 A young curator of a small museum in East London South Africa was looking through a pile of fish brought in by a fisherma. She instantly recognized something very different

16. She bought the specimen, which was about 4 feet in length made these drawings and notes sent them to J. B. L. Smith, who at the time was the most active Ichthyologist in Africa.
The rest is history..

17. Order Coelacanthiformes
Smith describes the coelacanth, Latimeria chalumnae, discovered in 1939, a true living fossil

18. Teeth 0n hard Bony plates plates Diphycercal tail
Why is it living fossil, just look at Courney-Latimer’s drawing…
Bony armor around head
Diphycercal tail
And I know its tough to read but she lists here teeth in hard plates
Remind you of anything??? PLACODERMS

19. The description made news around the world
What was now needed were more specimens..

20. A rewar of 100 pounds ($280) was put out to anyone who collect another specimen
A lot of money in those days,…..
Smith and many others began a searching all of the waters and fishing markets of Southern Africa
Finally, in 1952 he received word that another specimen had been caught in the Comores Islands NW of Madagascara about 1700 miles north of where the first specimen was captured

21. This is a pic. Of Smith with that second specimen.
You’ll notice in this picture that these other gentlemen in the background look like naval or air force officers. They are. This just give you an example of how big a scientific discovery the coelacanth was. When Smith got word of this second specimen, he was flown the next day by the Air Force up to the Comores Islands. The chances of getting that kind of service today are next to zero.
From 1952 on, specimens of coelacanths are collected with some regularity by fishermen using deep trawls

22. Marjorie Courtenay-Latimer
Brass plate at Latimer's
Landing East London.

23. Order Coelacanthiformes
“New” populaiton discovered at Sulawesi, Indonesia 1997
Found in a fish market by a zoologist who just happened to be in Sulawesi on his honeymoon.

24. Order Coelacanthiformes
“New” populaiton discovered at Sulawesi, Indonesia 1997
DNA analyses indicate divergence from L. chalumnae at Ma
Described as a new species L. menadoensis
One of the first (maybe only) example of a new species being described on the basis of molecular data rather than observable morphological differences

25. Order Coelacanthiformes

26. Order Coelacanthiformes
Symmetric three-lobed tail
Distal end has an epicaudal lobe

27. Order Coelacanthiformes
Oil filled gas (swim)-bladder
Craniovetebral joint (Placoderms also have these)
Increase gape

28. Coelacanth Biology
Lives along rocky shelves in deep (150 to 300 m) waters
Lurking predator, feeds on molluscs, fishes, and cephalopods
Stands on head while swimming, uses paired fins as paddles
Internal fertilization, ovoviviparous
Nocturnal predator
Can reach a very large size m
Ovoviviparous - females have very large eggs (largest known for fishes) that “hatch” internally, young develop with yolk sacs in uterus

29. Coelacanth “head standing”

30. Class Sarcopterygii Osteolepimorpha - extinct Coelacanthimorpha
Tetrapoda
Dipnoi

31. Obligate
Air-breathers
Divided lungs
Facultative
Air-breather
Unpaired lung

32. Order Ceratodontiformes - Australian lungfish

33. Order Ceratodontiformes - Australian lungfish

34. Order Ceratodontiformes - Australian lungfish
Neoceatodus forsteri
Southeast Queensland, Australia
Facultative air-breather, rely on gills

35. Order Ceratodontiformes - Australian lungfish
Neoceatodus forsteri
can reach a very large size

36. Order Lepidosireniformes
Pectoral and pelvic fins filamentous, without rays
Obligate air breathers - rely on lungs, will drown if it can’t reach the surface

37. Order Lepidosireniformes
Dig burrows with mouth
Secrete a mucus that will encase the body and prevent moisture loss

38. Order Lepidosireniformes
Dig burrows with mouth
Secrete a mucus that will encase the body and prevent moisture loss

39. Order Lepidosireniformes
Family Lepidosireneidae - S.A. lungfish
Lepidosiren paradoxa

40. Order Lepidosireniformes
Family Protopteridae - African lungifsh
Protopterus - 4 species

41. S.A. Lungfish Video

42. Review Questions
1. Draw the phylogenetic tree with the following groups: Myxiniformes,
Petromyzontiformes, Gnathostomata, Holocephali, Elasmobranchii,
Chondrichthyes, Osteichthyes, Actinopterygii, Sarcopterygii. List the
traits that define each of these groups.
2. Why was the discovery of the Coelacanth surprising and why were people
in the 1800’s excited by the finding? How many species of coelacanth are there?
What is the evidence for 2 separate species?
3. According to your book, which group of living fish are most closely related
to the tetrapods. Who were the Osteolepimorphs? Why are they important
to our understanding of the evolution of vertebrates?
4. Name the two orders and three families of lungfishes. List 2-3 traits of each.
Which families are obligate air breathers? What does it mean to be an obligate
air breather? Which family aestivates? Where is each family found?
5. Compare and contrast Coelacanths and Lungfishes in terms of reproduction,
presence/absence of lungs, presence/absence of oil filled swim bladder, and
properties of the caudal fin.

43. Review Questions (Cont’d.)
6. How do Coelacanths use their fins? Who was Jim Smith? Why was his
use of the term “old four legs” a bit misleading?
7. Who are “Ceratodontiformes” and “Lepidosireniformes”? Where do they
live? To what extent does each rely on its lungs (vs. its gills) for oxygen.
Which group aestivates? What do fish do when they aestivate? Compare
and contrast them in terms of body shape and pectoral and pelvic fin
structure.