 |
Dr. Mark L. Botton examines a specimen.
© Rebecca Wharton |
|
|
An Age-Old Survivor
The horseshoe crab, Limulus polyphemus, has been around for a very long time. Fossils from British Columbia (situated at the time in warm, shallow tropical seas) show that relatives lived in North America some 520 million years ago. The horseshoe crab went on to survive several mass extinctions, including ones that wiped out many other marine species. The habitat of this genus of the ancient animal is now restricted to a little peninsula on the Eastern shore of the United States, where it has been spawning since time immemorial in sequence with the phases of the moon. It now faces arguably the most serious crisis ever, one that is man-made.
. . . Until Now?
Between the 1880s and the 1920s about a million horseshoe crabs were harvested each year for use as fertilizer and in hog fodder. Chemical supplements replaced them, but fifty years passed before the crab population rebounded.
|
| |
|
1 of 9 |
|
 |
|
|
|