EQUINODERMAS

Apuntes

**EQUINODERMAS** - Spiny skin (short, sharp points like needles). - Many are carnivores. **PLATELMINTHES** - Some have tiny eyes! - Simplest organisms with organs and systems. * Free-living on water (e.g., planaria). * Parasites living inside vertebrates such as humans (e.g., tapeworms). - Basic nervous, respiratory, and excretory systems. - Most are hermaphroditic; some can reproduce sexually. - Around 20,000 different species. **NEMATODES** - Mouth and anus in distinct front and rear ends. - Sexual reproduction. - Parasitic. - Males and females are different! - Around 25,000 different species. **Reproductive System** - Possessing both male and female reproductive organs. **ANIMALS** - Most are aquatic. - Some are parasites (e.g., leeches). - Some live in tubes. - Some have gills. - Some are predators. - Some feed on suspended particles. - Some are hermaphrodites. **Molluscs** - Soft-bodied organisms protected by a shell made of minerals (not all). - Most are aquatic, but snails and slugs are terrestrial. - Aquatic molluscs breathe through gills; terrestrial ones through lungs. - Feeding habits: some are fi...