Are Horseshoe Crabs Older Than Fish?

Are Horseshoe Crabs Older Than Fish? They evolved in the shallow seas of the Paleozoic Era (540-248 million years ago) with other primitive arthropods called trilobites, a long extinct close relative of the horseshoe crab. Are horseshoe crabs the oldest crabs? Horseshoe crabs have been around for more than 300 million years, making them even

Can Fiddler Crabs Live Only In A Fish Tank?

Can Fiddler Crabs Live Only In A Fish Tank? These crabs are often marketed as freshwater pets (we even included them on our freshwater crab list). However, they don’t live in pure freshwater environments in the wild. To replicate their natural habitat, you must provide brackish water. Brackish water has low salinity, but it’s far