I found an obese sea star!

Well, maybe not the fattest individual, but definitely abnormal. I have never seen such fat individual of any species in the wild. If you don’t believe me take a look at this fat sea star. Yeah, that’s right, get into the habit of calling them sea stars – makes you feel so much better than calling them ‘starfish’ as they are not similar to fish in any aspect.

While on a routine data collection dive off Havelock Island in South Andaman, I found this individual lying on the reef like a toddler toy on the floor. The abnormally huge size of the sea star quickly caught my attention and I spent next 10 minutes taking pictures and observing the animal. Later, I googled by typing keywords ‘fat sea star’, but couldn’t obtain a single image of anything that looked even close to the individual I observed. The information that google search provided was rather curious. Take a look at the screenshot:

In addition, I also asked a few of my fellow marine biologists about the sea star and sent a few emails to scientists studying these animals. A few speculated abnormal growth and others mentioned that the fatness could be due to toxins in the body of a sea star. Later, I emailed an expert who is an Invertebrate Zoology staff at Smithsonian National Museum of Natural History and requested help with identification. As per the expert, this species of fat sea star belongs to genus Thromidia in the family Mithrodiidae and are closely related to Ophidiasteridae family.  In coming season, I am planning to take a few extra measurements of the species as per the suggestion of the expert who believes that the species could very well be the range extension.

The observation has raised my curiosity and I am keen to know more about the species distribution in our waters. If anyone has seen similar species or any such abnormal fat looking animals in the wild, then do share your experience, pictures or write-ups.