Dive Dry with Dr. Bill

#257: Take It to the Cleaners!

Now being a bachelor, I'm not one to spend a lot of time cleaning. Oh, I dust every decade or so, and do tidy up the house at least once a month. As for clothing, I haven't taken anything to a dry cleaner in decades (even if it needed it), nor do I purchase clothes that aren't wash-and-wear (albeit a bit wrinkly when I put them on). Perhaps this has something to do with my still being single... but, most truly eligible women divers see me in my wetsuit anyway. And most of mine should be taken to the trash dumpster rather than the cleaners!

In the marine world it is quite a different story. Fish and other critters often take it to the cleaners, seeking out other species who will "clean" them by picking parasites and dead or diseased tissue off their bodies. After all, our fine finned friends don't have arms and hands to do the job, so they have to rely on the kindness... er, the claws and mouths of others. Cleaning stations are common in tropical coral reefs. Fish go to these stations and wait in line for their turn to be cleaned by fish like wrasses or invertebrates like cleaner shrimp.

Here in our temperate kelp forests, cleaning stations are much rarer. Yes, giant sea bass will frequent areas of the reef where local wrasses like senorita and smaller sheephead, or island kelpfish, or kelp bass will clean them. Most of the time cleaning here is, to quote fellow Oak Park native and author Ernest Hemingway, a "moveable feast." The cleaners go to the "cleanee" rather than vice versa, although fish like halfmoon or blacksmith that need to be cleaned will often mob potential cleaners when they encounter them.

Last summer I was diving the deep pinnacle off the Edison Plant known as Little Farnsworth. Due to the depth, I had incurred a fair decompression obligation so I spent about 20 minutes hanging on the anchor line in blue water wishing something would come by for me to film. My wish was soon granted... two ocean sunfish, often commonly referred to by their scientific name (Mola mola) appeared. One stayed well away from me (probably the female), but the other drifted in to take a look at the weird bubble blower. Then from behind it appeared a halfmoon. It appeared to be inspecting the sunfish and actually pecked at parts of the body.

Although I frequently observe halfmoon being cleaned by senorita or rock wrasse near the bottom, I've never seen a halfmoon assume that role. I started up my high definition video camera and filmed this unusual interaction. This is the kind of thing I dive for... the discovery of new behaviors among our local residents. I watched and filmed for several minutes.

Although the visibility wasn't stellar, and the footage was slightly blurry, I was able to document this behavior to my satisfaction... at least until the other divers below approached the anchor line. Bubbles from their regulators rose toward the surface, and the sunfish, from below. Now I was hoping the Mola would think these bubbles were jellyfish or some other gelatinous critter that they'd find tasty, and they'd stick around. However, there were enough bubbles bursting at 20 feet to cause the ocean sunfish to express concern. At least that's how I interpreted the wide open oval mouth and body gyrations, seemingly an attempt to avoid the bursting bubbles. The Molas swam out of sight, ending my opportunity to further film this interesting interaction.

Years ago when I was teaching marine biology at the old Catalina Island School for Boys in Toyon Bay, one of my former students who was serving as a teaching assistant for me observed a similar interaction involving ocean sunfish. He was out collecting drifting kelp for the scientific study I was conducting with my mentor, Dr. Barry Fell, at Harvard University's Museum of Comparative Zoology. The student's name happened to be Barry as well... Barry Aires, although his fellow teaching assistant Packy Offield and I called him "Bam Bam." I won't go into the reasons here.

As we occasionally did while out collecting kelp "rafts," Barry saw several ocean sunfish nearby. He watched as one fluttered its dorsal fin at the water's surface. Some fish flutter or "vibrate" their fins when they are trying to attract the attention of a cleaner. Soon Barry saw a Heerman's gull land right next to the sunfish. The sunfish fluttered its fin again, then turned over on its side. The gull proceeded to take the sunfish's fins between its bill, apparently cleaning parasites off of them. Later, the gull swam off and the Mola attracted it back with the fin flapping. This behavior was observed several times by my students. Back in the mid-1970's I told Dr. Milton Love about it during one of Cousteau's Project Ocean Search programs which we both worked on, and he later published an article about it.

This behavior was certainly unique and very interesting to me. It represented the first time I was aware of that animals from the terrestrial and marine worlds communicated clearly with one another. Of course I don't consider the onslaught of bald eagles, pelicans, cormorants and gulls on baitfish and other fish species to be communicating anything but fear to the fish. And to the best of my knowledge, flying fish aren't trying to communicate anything to terrestrial critters that might see them take flight to avoid a predatory fish. However, the ocean sunfish appeared to be directly communicating with the gull... and the gull understood the message, and acted appropriately. Now if only we could get members of our own species to communicate as clearly to one another as these vastly different critters did.

NOTE: There is an excellent video about diving Catalina Island that is available over the Internet on the Bloomberg Financial News' website. It features interviews with Jean-Michel Cousteau, Mayor and SCUBA Luv co-owner Bob Kennedy, and Dr.Bill. The video was put together by Matt and Nadja Brandt for Bloomberg. To see it, log onto the Bloomberg web site (, and search the site on the keywords "Cousteau" and "giant sea bass." You can read the accompanying article by Nadja, then to the right of it select the accompanying media "Diving in the Emerald Forest off Catalina." It's a pretty nice introduction to our underwater world and why many of us love to dive here.

© 2007 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays. Please help me climb out of self-imposed poverty... buy my "Munching and Mating in the Macrocystis," "Great White Sharks of Guadalupe," "Calimari Concupiscence: Mating Squid, " "Playful Pinnipeds: California Sea Lions," "Belize It or Not: Western Caribbean Invertebrates, Fish and Turtles," "Gentle Giants: Giant Sea Bass" or "Common Fish and Invertebrates of the Sea of Cortez" DVD's. Yes, take Dr. Bill home with you... we'll both be glad you did!

Ocean sunfish (Mola mola) and halfmoon inspecting and cleaning it; gull cleaning Mola at the surface (image courtesy of Frank O'Donnell).

This document maintained by Dr. Bill Bushing.
Material and images © 2007 Star Thrower Educational Multimedia