1.
In 2003, a study found there were this number of adult horseshoe crabs in Pleasant Bay:
Correct Answer
B. Half-million
Explanation
A study in 2003 revealed a horseshoe crab population of a half-million adults and 13.5 million juveniles in Pleasant Bay.
2.
How many species of horseshoe crabs are there?
Correct Answer
D. 4
Explanation
There are only four species of horseshoe crabs in existence in the world today. These are Limulus polyphemus, Tachypleus gigas, Tachypleus tridentatus, and Carcinoscorpius rotundi-cauda. Only one of these species is found in North America.
3.
How old are the earliest species of horseshoe crabs?
Correct Answer
C. 450 million years old
Explanation
Horseshoe crabs are believed to be one of the oldest living species on Earth, with fossil records dating back around 450 million years. This makes them significantly older than dinosaurs. Their evolutionary history can be traced back to the Late Ordovician period, and they have remained relatively unchanged since then. The longevity of horseshoe crabs can be attributed to their unique adaptations and resilience, allowing them to survive and thrive for millions of years.
4.
Is the horseshoe crab a true crab?
Correct Answer
B. False
Explanation
Horseshoe crabs belong to the phylum, Arthropoda. Their closest relatives are spiders and scorpions.
5.
How many pairs of legs do horseshoe crabs have?
Correct Answer
D. 7
Explanation
Horseshoe crabs have seven pairs of legs under their helmet-like shells; five of these seven pairs of legs are equipped with claws.
6.
Does a horseshoe crab have a nose?
Correct Answer
B. False
Explanation
The horseshoe crab has no nose, but the tiny hairs on the spiny projections around its mouth are chemoreceptors, allowing the crab to smell prey.
7.
What part of the horseshoe crab is used for medical research?
Correct Answer
D. All of the Above
Explanation
All of the above options are used for medical research in horseshoe crabs. The blood of horseshoe crabs contains a substance called Limulus amebocyte lysate (LAL), which is used to test for bacterial contamination in medical equipment and vaccines. The eyes of horseshoe crabs are used to study vision and neurobiology. The chitin or shell of horseshoe crabs is used to develop wound dressings and other medical products. Therefore, all these parts are valuable for medical research purposes.
8.
The biggest crab population in Massachusetts is in:
Correct Answer
A. Monomoy in Chatham
Explanation
Pleasant Bay is second in the state only to Monomoy in Chatham in its crab population.
9.
Horseshoe crabs have been used for:
Correct Answer
D. All of the Above
Explanation
Horseshoe crabs have been used for various purposes including the production of skin creams and hair sprays, as fertilizer, and as feed for chickens and hogs. Therefore, the correct answer is "All of the Above".
10.
Horseshoe crab blood is useful for:
Correct Answer
D. All of the Above
Explanation
Horseshoe crab blood is useful for detecting deadly toxins in medical products because it contains a substance called Limulus amebocyte lysate (LAL), which clots in the presence of bacterial endotoxins. This makes it an effective tool for ensuring the safety of vaccines, intravenous drugs, and medical devices. Additionally, horseshoe crab blood is used for testing fungal infections as it can identify the presence of fungal pathogens. Furthermore, research has shown that horseshoe crab blood exhibits anti-viral and anti-cancer activity, making it a potential source for developing new treatments. Therefore, the correct answer is "All of the Above."