These brittlestars (Ophiothela mirabilis) are not where they belong. These animals, usually found in the Pacific Ocean, were first spotted in the Atlantic Ocean off the coast of Brazil in 2000. And since then, they've been seen crawling up and down the eastern coast of South America, all the way north to the Caribbean. O. mirabilis has been observed in ports up and down the coast, suggesting that it was brought to the Atlantic from the Pacific by ships.
The invasive species hasn't hurt Atlantic ecosystems yet, but scientists such as Gordon Hendler from the Natural History Museum of Los Angeles County are worried. These brittlestars are able to reproduce asexually by splitting their bodies down the middle and regenerating the missing halves, allowing them to spread along the coastline very quickly. (You can see split brittlestars in the photo!) "Unfortunately, too little is known of the species’ biology to predict its potential impact on Atlantic reef communities," Hendler wrote in a recent paper.
Have you seen this brittlestar? Please contact Gordon Hendler so he can track their spread.