Marine (Saltwater):
* Fish: Many fish species graze on seaweed, especially herbivorous fish like parrotfish, surgeonfish, and tangs. Others, like wrasse and pufferfish, may nibble on seaweed as part of a mixed diet.
* Sea urchins: These spiky creatures are major seaweed grazers, sometimes causing "urchin barrens" where they consume large amounts of kelp.
* Sea turtles: Green sea turtles are primarily herbivorous, with a diet consisting mainly of seagrass and some seaweed.
* Sea hares: These slug-like mollusks are herbivores, and some species specialize in feeding on specific seaweed types.
* Other invertebrates: Many snails, limpets, crabs, and even some shrimp species will consume seaweed.
* Larger mammals: Some mammals like manatees (sea cows) and dugongs also feed on seagrass and seaweed.
Freshwater:
* Fish: Some freshwater fish species, like the silver dollar fish and some types of carp, will eat algae, including seaweed-like species.
* Turtles: Some freshwater turtles, like the red-eared slider, will consume algae, including some seaweed-like species.
* Snails and other invertebrates: Freshwater snails, limpets, and some types of shrimp will eat algae, including seaweed-like species.
Important Note: It's worth noting that not all seaweed is edible. Some species are toxic to humans and animals, and many are unpalatable. The animals mentioned above have evolved specific adaptations and digestive systems to handle the specific types of seaweed they consume.