Scenario The Dune-Burrowing Spider Seothyra Species Lives in the Namib Desert

question 44

Multiple Choice

Scenario
The dune-burrowing spider Seothyra species lives in the Namib Desert on the southwestern coast of Africa. These spiders build silk-lined burrows with a sticky silk mat at the entrance to trap insect prey. While foraging during the day, the spider remains concealed in its burrow and shielded from direct sunlight when prey are not present. When insect prey become entangled in the sticky silk mat, the spider will run out of its burrow and capture the prey insects.
During the day, environmental temperatures vary from 17 to 73°C (63-164°F) . If a spider is forced to remain outside of its burrow, it shows signs of thermal stress at 49°C. When spiders are unrestrained, they spend more time waiting inside their burrows to keep their internal temperatures below 49°C, even when surface temperatures are above 65°C. In addition, spiders respond more quickly to prey stimuli during the hottest times of the day and capture prey in significantly less time when surface temperatures are above 49°C. The captured arthropods (prey) tend to succumb more quickly to hot surface temperatures; they are more lethargic and struggle less when captured at the high temperature ranges.
-Based on the information in the paragraphs, spiders are ________.

• A)ectotherms
• B)endotherms
• C)sometimes ectotherms and sometimes endotherms
• D)neither ectotherms nor endotherms