|Not a smiling coral, but a fluffy sea slug on its prey, a half eaten finger coral (Porites compressa) ( Photo - M. Heckman)|
Such was the case recently - I noticed earlier in the week that a couple of the coral fragments looked seriously sick. They were discolored and pale, so I examined them for parasites and isolated them from the others. A day later I checked again and the culprit had finally gorged itself sufficiently that it it was large enough to be discovered. It was the coral eating sea slug Phestilla lugubris (the "smile" on the coral above).
|Phystilla sea slug, C. Pittman photo|
Interestingly, we had this same problem last year at about the same time. In that case, the corals looked fine on Friday and were a mess by Monday. In fact, the sea slugs last year were so well fed in just a few days, that they were already busy laying eggs by the time I got to them.
|Note the sea slug at top, the areas that the sea slug has eaten and the |
various egg masses that it has laid - all in one weekend.
|Closer view - M. Heckman Photo|
|Old woman wrasse|
|Gonodactylaceus mantis shrimp from |
Introduced Marine Species of Hawaii
|Areolated xanthid crab|
These are one of the few sea slugs for which scientist have figured out the entire life history - egg to adult in less than 40 days! Adults live only a few months, lay thousands of eggs a day, then die a couple of weeks later. Contrast this to an adult sea cucumber that might live decades or more. Some invertebrates move slow and live slow, some move slow and live fast. Phestilla may crawl slow, but they can eat 10 square inches of coral a day, then lay thousands of eggs and pass away, leaving their progeny to continue on.
Crawl slow, eat large, live fast.
For some great sites on these animals (and some of my references for this article), see:
|Bill Rudman photo|
|Pauline Fiene photo|
|Dana Riddle Photo|
Advanced Aquarist by Dana Riddle: Broad coverage, information for those who keep corals in captivity and the most up to date information. See: //www.advancedaquarist.com/2012/6/inverts