I am having a love affair with this tiny little Sacoglassan sea slug called Placida cremoniana. I know, it all sounds like scientific jibberish, so putting all the big words aside, I’ll just call it PC.
In the past few weeks, I have made several trips out to Catalina Island to search for the tiny beast. It was necessary to collect some specimen so that their DNA could be analyzed, as they have never been found in California. This will tell us whether PC came from the bilge of a passing ship, or if it has spread slowly from the south, or if it is an entirely new critter altogether. Interestingly enough, the slug seems to be plentiful in numbers. I found them as small as 1mm and as large as about 6mm in length.
The unusually warm waters along the Pacific coast for the past year or more have encouraged many warm water life forms to journey north. Most of the sightings have been of very large creatures such as a Whale Shark, Sperm Whales, Hammerhead sharks, and a plethora of fish such as yellowfin Tuna, Mahi Mahi, and even Ono. I was lamenting the fact that I haven’t seen any of these southern visitors yet, when I found this very tiny sea slug. I guess I should have set my sights smaller in the first place!
If it is just a warm water visitor, then it may be a temporary condition. Kinda sad, when you think about it. If it cannot survive in California’s usually temperate water, then an entire population may disappear from our waters. When you consider that I have been able to find them on every dive I have been on since I first found one, that becomes a very large population. I hope to be able to report soon where this critter has come from. If it truly is Placida cremoniana, then it is thought to have originated in the Mediterranean and spread to the western Pacific from Japan all the way to Australia. Several years ago, one was found in Baja, so the possibility of it coming up from the south is an interesting one. Stay tuned….