Here is a concise summary of the text:
**Title:** Fascinating Animal Adaptations and Unique Features
**Summary:** This text highlights extraordinary biological features and adaptations in various animals, including:
1. **Organ variations**:
* Horses (no gallbladder)
* Salamanders (no lungs, breathe through skin)
* Snakes (one lung)
* Platypus (no stomach)
* Flatworms (no blood, rudimentary circulatory system)
2. **Unusual body parts**:
* Humans (unique chin structure)
* Jellyfish (no sensory organs, brain, or heart)
* Hagfish (four hearts)
* Horseshoe crabs (seven eyes)
3. **Specialized senses and abilities**:
* Sea stars (external stomach, no blood or lungs)
* Vipers (thermal sensor for detecting prey)
* Sharks (electricity sensor for detecting electromagnetic impulses)
* Bombardier beetles (explosive chemical defense)
* Boxer lobsters (16 light-sensitive eyes)
* Snapping shrimp (extremely fast, hot-air-bubble-generating pincer)
4. **Unique survival mechanisms**:
* Hippos (produce their own sunscreen, can run at high speeds)
Here are the key facts extracted from the text, without opinions, in short sentences with numbers:
**Anatomy and Physiology**
1. Humans need a gallbladder to store bile for fat processing.
2. Horses do not have a gallbladder.
3. Salamanders can breathe through their skin, not lungs.
4. Some species of snakes have only one functioning lung.
5. Spiders have eight legs and multiple eyes.
6. The asexual spider (Locus anops) is a rare species without eyes.
7. Platypuses have venom, but no stomach between their esophagus and intestines.
8. Cows have four stomachs (actually, one stomach with four cavities).
9. Flatworms do not have blood or a complex circulatory system.
10. Humans have sweat glands, unlike many predatory animals (e.g., cats, dogs).
11. The chin is a bony protuberance extending forward and below the lower jaw, unique to humans.
**Unique Animal Features**
12. Jellyfish do not have sensory organs, a skeleton, brain, or heart.
13. One species of jellyfish can live indefinitely in a safe environment.
14. Hagfish have four hearts.
15. Sperm whales have a similar stomach structure to cows (four-cavity stomach).
16. Horseshoe crabs have two eyes on the sides of their head and five more on top of their shell.
17. Many animals have a nictitating membrane (a third, semi-transparent eyelid).
18. Humans once had a nictitating membrane (remnants visible in the corner of the eyes).
19. Sea stars do not use their mouth to eat; instead, they extrude their stomach.
20. Sea stars are bloodless, without a circulatory system or lungs.
21. Vipers have a thermal sensor organ to detect warm-blooded prey.
22. Sharks have an electricity sensor near their nose to detect electromagnetic impulses.
23. Bombardier beetles can release a mixture causing an explosive reaction for defense.
24. Boxer lobsters have 16 light-sensitive "eyes" to see hundreds of colors.
25. Snapping shrimp can create a hot air bubble (temporarily near the sun's surface temperature) to knock out prey.
26. Hippos produce their own sunscreen (a pink sweat) to protect their skin.
27. Hippos can run at speeds similar to a scooter (approximately 18-25 mph).
**Miscellaneous**
28. Flatworms are parasites that can live in flooded regions or within other animals (including humans).
29. Some species of jellyfish can live forever in a safe environment.