The Coelacanth
An Odd Fish
©SAIAB
by
Eric Ribbens, Western Illinois University,
based on a case by Robert H. Grant
1
Marjorie Courtenay-Latimer
(born February 24, 1907)
Marjorie was the
curator of the East
London museum in
South Africa.
2
December 23, 1938
“My friend, Capt. Hendrick Goosen, had just
returned from a trawling trip around the
mouth of the nearby Chalumna River.
Hendrick often calls on me when his catch is
substantial so that I can look and see if there
may be anything of scientific interest for the
museum. More often than not, I find nothing
but a pile of malodorous fish.”
3
December 23, Continued...
“… a strange bluish fin poking through the pile
caught my eye. It was like no fish fin I had ever
seen in all my years at the museum.”
4
Discussion Question
What do you see that might have led Ms.
Courtenay-Latimer to believe that such a
fish might be special?
5
What did Marjorie see?
• Marjorie wrote: “The Captain and I shoved
the other fish off the top of the pile to
uncover the owner of the odd fin. There it lay
before me, the most beautiful fish I had ever
seen, five feet long, and a pale mauve blue
with iridescent silver markings.”
6
Discussion Question
• Imagine you are Marjorie Courtney-Latimer.
You have found an unusual fish, 127 lbs. and 5
feet long. It’s a really hot day, and you don’t
really know that much about fish, so you don’t
know if this is really a significant find or not.
• What should you do?
7
CQ#1: What do you think she did?
A: Sketched the fish and took some
measurements.
B: Asked the captain to have the fish delivered
to the museum.
C: Took some pictures with a camera and
collected a DNA sample.
D: Loaded the fish into the back of a taxicab.
8
What should she do?
• Marjorie wrote: “I am no fish expert, but I had
the strange feeling that somehow this fish
was special. I decided to take the fish with
me, and after a heated discussion with the
taxi driver, we stuffed the huge fish into the
backseat of the cab and headed off for the
museum…”
9
CQ#2: When Marjorie showed the
fish to the museum director, he:
A: Said it was just an ordinary fish.
B: Became excited and told her to find a fish
expert to look at it.
C: Asked her to please remove that big dead
fish before it began to smell.
10
What next?
• The next day Majorie wrote in her diary:
“Could not believe that the director of this
museum would not even consider the bizarre
appearance of this fish as unique. To think, he
said it was just another rock cod! I feel that it
definitely resembles some of the pictures I
found in Fossil Fishes of the World.”
11
Here’s a Rock Cod:
12
And here’s Marjorie’s fish again:
©SAIAB
13
Marjorie’s fish
Rock cod
14
What do you think?
• Was it a rock cod?
• What differences or similarities do you see?
15
Continuing from her diary:
• “This is the first time I’ve wished
my expertise lie in fish instead of
birds. I must contact J.L.B. Smith
in Grahamstown.”
• J.L.B. Smith was an expert about
fish.
©SAIAB
16
Waiting…
©SAIAB
But Dr. Smith had gone on vacation, and so Marjorie had the
decomposing fish mounted by a taxidermist. The picture above is a
drawing she sent Dr. Smith. After the mounting, she received a
telegram on January 3rd from Dr. Smith:
MOST IMPORTANT PRESERVE FISH AND GILLS = FISH DESCRIBED.
17
February 16, 1939
• “Dr. Smith arrived today and has caused quite a stir.
He positively identified the fish as a coelacanth, a fish
that was thought to have been extinct for about 70
million years! My hunch was correct! We have found
a living fossil. Dr. Smith said that this fish and its
relatives were swimming in seas and lakes when T.
rex walked the Earth! Cannot begin to describe my
excitement.”
18
A Fossil Coelacanth
19
Dr. Smith and the coelacanth
©SAIAB
20
CQ#3: The youngest coelacanth fossil found
has been dated to 70 million years ago.
Why was there a gap of 70 million years in
the coelacanth’s fossil record?
A: Coelacanths became extinct 70 million years
ago, and then re-evolved.
B: Coelacanths may have become much rarer 70
million years ago.
C: The fossils must be out there, they just
haven’t been found yet.
21
Discussion Question
• Why was Dr. Smith excited, and why would a
scientist interested in evolution be excited?
(Think again about the structure of the fish.)
22
Discussion Question
• It’s been argued that the coelacanth is a
“missing link”. Look at the phylogenetic tree
on the next slide and explain why it has been
described that way.
• It’s also been argued that because it is alive
today it’s not a missing link. What do you
think?
23
Where are the
Lobe-Finned
Fishes?
24
CQ#4: Is the coelacanth a “missing link”?
A: Yes
B: No
C: Missing links are only found in human
evolution
25
Evolution
This diagram shows that
the coelacanth is more
closely related to
mammals and other
more derived
vertebrates than the rayfinned fishes are. This
means that coelacanths
have more derived
characteristics (fewer
ancestral) than the rayfinned fish do.
26
CQ#5: If coelacanths are more derived,
why are ray-finned fish more common?
A: Ray-finned fish are actually the more
derived. The diagram is wrong.
B: Derived traits don’t mean that those
organisms are more abundant.
C: Coelacanths haven’t been found in
abundance yet, but they must be.
27
CQ#6: Did the captain and his crew catch
the LAST coelacanth?
A: Yes
B: No
28
Discussion Question
• If you were a scientist interested in
coelecanths, what would you do next?
• If there are more coelacanths, why is it
important that they are found?
29
30
Fun Facts
• Ms. Courtenay-Latimer, Dr. Smith, and their coelacanth became
overnight celebrities. For a one-day-only showing of the
coelacanth in East London in 1939, 20,000 visitors reportedly
showed up.
• Fossils of the class of fish to which the coelacanth belongs
appeared some 400 million years ago, mostly in fresh water
environments on all continents except Antarctica.
• The fish specimen was named Latimeria chalumnae in honor of
Ms. Courtenay-Latimer and the area in which it was caught
(Chalumna River mouth).
31
Marjorie and Coelacanth
32
More Fun Facts
• At the time of the discovery, it was thought that the coelacanth
may have been the fish species that led to the first land
amphibian, using its fleshy limbs to walk onto land.
• Another living coelacanth was not found until 14 years later. It
was caught by a fisherman in the Comoros Islands hundreds of
miles north of the Chalumna River. Its internal organs were
preserved, leading to many interesting insights into its biology.
• Based on recent and ongoing observations of coelacanths off the
Comoros, scientists know that coelacanths live about 180 meters
deep in caves, bear live young, and live for about 60 years.
33
©SAIAB
34
Discussion Question
• Comoros fisherman had known about the fish
for years, calling it “Gombessa.”
• If native people knew about coelacanths but
the western world did not, did Marjorie
Courtney-Latimer discover it? Did Dr. Smith?
35
Today
• In 1997, two American scientists visiting Indonesia
spotted a coelacanth at a fish market. DNA studies have
shown it to be a different species of coelacanth,
Latimeria menadoensis. Indonesian fisherman had also
known about this fish for years, calling it “Raja Laut”—
King of the Sea.
• Small populations of coelacanths have been found off
the east coast of Africa and one off the coast of
Indonesia. Global numbers of both species combined
are estimated at about 1,000 individuals. Latimera
chalumnae is listed as critically endangered by the
International Union for Conservation of Nature and
Natural Resources.
36
Latimeria menadoensis
37
Marjorie Courtenay-Latimer died on May 17,
2004, aged 97
38
Slide Credits
Slide 1, Slide 17
Description: Pencil sketch of coelacanth
Source: South African Institute for Aquatic Biodiversity (SAIAB).
Author: Marjorie Courtenay-Latimer
Licensing: Used with permission, which must be sought directly from SAIAB, http://www.saiab.ac.za/.
Slide 2
Description: Photo of a youthful Marjorie Courtenay-Latimer.
Source: East London Museum
Licensing: Used with permission of East London Museum.
Slide 4, Slide 5, and Slide 14—Top
Description: Illustration of Latimeria chalumnae
Source: FishBase,
http://www.fishbase.org/Photos/PicturesSummary.php?StartRow=4&ID=2063&what=species&TotRec=6
Author: Robbie Cada
Licensing: Creative Commons Attribution 3.0 Unported License
Slide 12, Slide 14—Bottom
Description: Photo of estuary cod
Source: http://www.reefpix.com.au/petedog.jpg
Author: Peter Heatherwick
Licensing: Used with permission of the author.
39
Slide 13, Slide 34
Description: Photo of Indonesian coelecanths
Source: South African Institute for Aquatic Biodiversity (SAIAB).
Author: JAGO team, SAIAB Catalog Number : 78774 Person : German JAGO Team Date : 22/06/2006
Licensing: Used with permission, which must be sought directly from SAIAB, http://www.saiab.ac.za/.
Slide 16
Description: Photo of Dr. J.L.B. Smith
Source: South African Institute for Aquatic Biodiversity (SAIAB).
Licensing: Used with permission, which must be sought directly from SAIAB, http://www.saiab.ac.za/.
Slide 19
Description: Fossil of Undinapiscis penicillata, an extinct coelacanth
Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Undinapiscis_penicillata.JPG
Author: Ghedoghedo
Licensing: Creative Commons Attribution ShareAlike 3.0 License.
Slide 20
Description: Photo of Dr. J.L.B. Smith and crew with coelacanth.
Source: South African Institute for Aquatic Biodiversity (SAIAB).
Licensing: Used with permission, which must be sought directly from SAIAB, http://www.saiab.ac.za/.
Slide 24, Slide 26
Description: Phylogenetic tree
Source: Based on Atlas of Life on Earth by Douglas Dixon, Ian Jenkins, Richard T. J. Moody & Andrey Yu.
Zhuravlev (Barnes & Noble, 2001, p. 368).
Author: Jim Stamos, Department of Biological Sciences, University at Buffalo, 2005.
Licensing: Used with permission.
Slide 30
Description: Preserved specimen of coelacanth in the Natural History Museum, Vienna, Austria.
Source: Wikimedia Commons,
http://commons.wikimedia.org/wiki/File:Latimeria_Chalumnae_-_Coelacanth_-_NHMW.jpg
Author: Alberto Fernandez Fernandez
Licensing: Creative Commons Attribution ShareAlike 3.0 License.
Slide 32, Slide 38
Description: Marjorie and the coelacanth
Source: East London Museum
Licensing: Used with permission of the East London Museum
Slide 37
Description: Photo of coelacanth with diver.
Author: Mark V Erdmann, Conservation International Indonesian Marine Program.
Licensing: Used with permission.