I snapped this photo on the same dive that I shot the mating pair of gold-crowned nudibranchs not far offshore from Key Biscayne on Emerald Reef.  I am not 100 percent certain of the identity of this fish.  When they are this size (<3 inches), the juveniles of high hats (Pareques acuminatus), jackknife fish (Equetus lanceolatus), and spotted drums (Equetus punctatus) look nearly identical. As the latter species suggests, all three of these species are part of the drum family (so called because of some members’ ability to “vocalize” during courtship and mating). If I had to hazard a guess I’d say that this one is a high hat, based on the spot on its nose and band across the eyes. To really appreciate the beauty of this fish though, you have to observe it in action:  It takes full advantage to its long finnage as it undulates and swims cyclically. Because of it’s constant motion, it can be deceptively difficult to photograph. For such a defenseless fish, these movements must be confusing enough to thwart most predators. The juveniles stay mostly protected underneath ledges, caves, and near crevices. Unfortunately, the grace and beauty of the high hat declines over time as the long dorsal and caudal (tail) fins shrink in proportion to the body.  Jackknife fish and spotted drums by comparison keep their long fins into adulthood, although they are still most exaggerated as juveniles.

This past Friday, I was fortunate enough to come across this pair of beautiful gold-crowned sea goddess nudibranchs (Hypselodoris acriba) while diving off of Key Biscayne. I have never seen this species before as it is quite rare in Florida waters. To observe this pair mating was especially fortunate. If you look at about 12 o’clock in the photo, you will notice the genitalia of the slugs in the process of exchanging genetic material. Like all sea slugs, these gold crowned sea goddesses are hermaphrodites, thus any two make a viable breeding pair. This species is an obligate sponge feeder, making them very difficult to keep in a general reef aquarium. They are better off left in the ocean.