1. The Horseshoe Crab: A True Blue-Blood
NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Photo credit: Breese Greg, USFWS
The Horseshoe Crab: A True Blue-Blood by
Kathleen A. Nolan
Department of Biology, Health Promotion and Health Care Management
St. Francis College, Brooklyn, NY

2. CQ#1: What causes the blood to be blue?
The iron in hemoglobin
The copper in hemoglobin
The copper in myoglobin
The iron in hemocyanin
The copper in hemocyanin

3. Kin, A., & Błażejowski, B. (2014). The Horseshoe Crab of the Genus Limulus:
Living Fossil or Stabilomorph? Plos ONE, 9(10), 1-11.

4. Can you tell the male and the female apart? How?

5. Male
clasper appendages

6. Spawning in Delaware Bay

7. Horseshoe crabs spawning

11. Red knots feeding on horseshoe crab eggs.

13. Can you guess what these are?

14. Photo courtesy Mark Botton, Ph.D. Fordham College
Embryos!

17. Can you guess what these horseshoe crabs were used for?
RG Board of Agriculture Glass Negative Collection Creator Hammond, Roydon L.
Delaware Public Archives
Can you guess what these horseshoe crabs were used for?

18. RG 1380.006 Board of Agriculture Glass Negative Collection Creator Hammond, Roydon L.
Delaware Public Archives
FERTILIZER!!

19. Watch this three-minute video on one of the key stakeholders:
NATURE | Crash: A Tale of Two Species | Blue Blood | PBS 3 min.

20. CQ#2: What is the net worth of a liter of horseshoe crab “blood” (hemolymph)?
$10,000
$100
$15,000
$1000
1 million dollars

21. CQ#3: How many horseshoe crabs are taken for “blood-letting” every year from the five LAL companies in the U.S.?
10,000
1,000
1 million
500,000
300,000

22. CQ#4: Limulus amebocyte lysate (LAL) works in the following way:
Amoebocytes react with harmful viruses
Amoebocytes react with endotoxins produced by bacteria
Hemocyanin reacts with endotoxins produced by viruses
Hemocyanin reacts with endotoxins produced by bacteria
Amoebocytes react with endotoxins produced by fungi only

23. CQ#5: According to Leschen and Correia (2010), what was the approximate mortality of the horseshoe crabs in their study?
10%
15%
30%
40%
50%

24. CQ#6: An organism that is an osmotic conformer…
Changes its osmolality at various salinities
Is not able to change its osmolality at various salinities
Can only adjust to one salinity
Needs to conform to a certain hemocyanin saline concentration
Needs to conform to a certain hemocyanin glucose concentration
photograph by Lauren Clarke

25. What is meant by
“landings”?
Can you explain the peak?

26. What is a “quota distribution plan?”
(This one is for NY.)
Why is it variable?

27. Quotas set by ASMFC for HSC’s for 2018
Compare and contrast these data.
Quotas set by ASMFC for HSC’s for 2018

28. Discuss trends that you see.

30. Stakeholder Table Educator Ecologist Paleontologist Medical researcher
Conservation
Development
Educator
Ecologist
Paleontologist
Medical researcher
Bird watcher
Environmentalist
Hotel owner
Eel fisherman
Bait collector
Government scientist

31. What are your conclusions?

32. Image Credits Slide 1 Gregory Breese/USFWS, public domain
Slide 3
Kin, A., B. Błażejowski Plos ONE 9(10): 1–11. CC BY 4.0
Slide 4.
Curious Expeditions, CC BY-NC-SA 2.0
Slide 5
MauriceJFox3, CC BY 2.5
Slide 6
Slide 7
Asturnut, CC BY-SA 3.0
Slide 8
Hayden, CC BY 2.0
Slide 9
Michael Lusk, CC BY-NC 2.0   
Slide 10

33. Slide 11
Gregory Breese/USFWS, public domain
Slide 12
Mark Botton, used with permission.
Slide 13, 14 (Horseshoe crab embryos)
Doug Wechsler, used with permission.
Slide 14 (Photo of larva on right)
Photo by Mark Botton. Used with permission.
Slide 15
Derek Perry, used with permission
Slide 16
CC BY-SA 2.0
Slides 17 and 18
Delaware Public Archives, used with permission.
Slide 20
Chosovi. CC BY-SA 2.5
Slide 21
Didier Descouens, CC BY-SA 4.0
Slide 22
Slide 23
domdomegg, CC BY 4.0

34. Slide 24
Photo by Lauren Clark, student of K. Nolan, used with permission.
Slides 25, 27, 28 and 29
Atlantic States Marine Fisheries Commission, used with permission.
Slide 26
New York State Department of Environmental Conservation, used with permission.
Slide 30
Table made by K. Nolan
Slide 31
Didier Descouens, CC BY-SA 4.0