Sunday, 22 May 2016

Atlantic Black Sea Hare

Aplysia morio
Atlantic Sea Hare




          On May 17, 2016 our cohort ventured to Long Key Point to snorkel and survey the area for general comparative conditions and identify the organisms within the community, in this case, a hard bottom system with corals, seagrass and algae all within the same area. I was swimming along in waters that were only about three to four feet deep and noticed what looked like a black blob on the sea floor. I proceeded to stare at the blob to see if it would move around but it simply swayed with the moving water, so I called Dr. Voss over and he quickly identified it as a sea hare. I got to hold the sea hare and it was very slimy and it was then that I noticed the flaps extending from mantle. As I let the sea hare go on it's merry way, it flapped its 'wings' and swam away from us, from which I got a video of it's graceful 'flight'.

video

          Upon investigation, this sea hare was identified as Aplysia morio, commonly known as the Atlantic black sea hare. Sea hares are marine invertabrates that belong to the Phylum Mollusca and are specifically in the Class Gastropoda, which includes shelled organisms but this is a non-shell forming gastropod. The sea hare is within the subclass Opisthobranchia which means that they have two tentacles on their mouth and two rhinophores on top of their head used as receptors to taste and smell. The distinct difference between a nudibranch and a sea hare is the adaptation of their parapodium, which are the flaps of skin extending from the mantle that help them swim within the water column. 
          An interesting adaptation used for predator evation by the sea hare is the secretion of an ink solution (often purple in color) that is toxic to other organisms but is harmless to humans. Aplysia feed on a red alga called Laurencia sp. and also use the alga to hide their broodstock in to protect from potential predation. 
          Aplysia morio are found geographically in Bermuda and the Eastern United States, most commonly in Florida, but also in Texas as well. The typical habitat for the sea hare is a shallow intertidal region with an abundance of algae, but can be found as deep as 40 meters. It is heavily documented that when there are storms present, sea hares wash ashore in great numbers. It seems normal to have found this Aplysia morio at Long Key Point due to the breadth of algae that covered the sea bed and even though the wave energy was more than they are used to, the Atlantic black sea hare was using the hard coral substrate to hold on. I very much enjoyed seeing this organism and cannot wait to see what we find next!

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