Dive Dry with Dr. Bill

#246: Keep It Clean!

Most of my regular readers are probably assuming the title of this week's column means that I won't be talking about my favorite three letter word... you know, the one related to Mating. For once they are right! After all, there is more to life than that... I think. I'm going to focus on the other "M" word, Munching. However this will be a bit different from a school of barracuda attacking topsmelt, or a kelp bass darting in to devour a jack mackerel. Yet it does involve all the sheer terror of the "mutual eating society..." at least for the victims... er, the food.

The giant sea bass have been a real love of mine ever since they started returning to our waters after near local extinction in the late 1960's and 1970's. Restrictions imposed in the 1980's and 1990's on long lining and gill nets in California's coastal waters, and a ban on the take of these gentle giants by rod and reel or speargun, saved this species and created what appears to be a slow but steady recovery. I've already written about these goliaths in previous articles, so regular readers know more than they ever expected to about their courtship, ecology and munching behavior.

You also know about the large numbers of copepod parasites that infest these fish. Now parasites are a pain in the... er... butt, or intestine, or blood stream, or wherever they reside within their host. These copepods appear to be largely ectoparasites, attaching externally to the skin of the fish. They remain highly mobile, often shifting positions before my camera like a frantic stage crew preparing for the next scene in a stage play. I assume the bass is slightly irritated by hundreds of these little crustaceans crawling over its body, and seeks some relief from their onslaught.

The relief comes in the form of other fish which act as cleaners, picking the parasites off the giant bass and munching them down as an easy hors d'oeuvre. I spent a lot of time filming the sea bass this past weekend, and focused largely on the cleaner species involved in this process. It is interesting to note that Kathy deWet-Oleson, while researching this behavior off Anacapa Island, noted that island kelpfish seem to be the primary cleaning fish, and that the activity occurs at fixed cleaning stations near rocky reefs and kelp beds. Based on my observations in our waters, I have never seen an island kelpfish clean them nor the sea bass use fixed locations for this. Our cleaners include senoritas, rock wrasse and kelp bass.

I saw no senorita cleaning giant sea bass this weekend. Perhaps it was their weekend off. However, I did film both rock wrasse and kelp bass doing so. They differed in their methods, perhaps each specializing in a different part of the bass' body. The rock wrasse focused on the rear part behind the pectoral fins. They leisurely inspected the dorsal, ventral and anal regions as well as the side of the body and pectoral fins. The rock wrasse appeared cool, calm and collected. I never saw them venture near the head... where the bass' cavernous mouth might "mistakenly" slurp them inside.

On the other hand, the kelp bass had a more daring strategy... or perhaps it was an ill-informed one like our "incursion" into Iraq. Although they spent some time at the rear of the body, they rarely seemed to clean (grab parasites) there. The parasite population in this region of the body tends to be sparse, so the pickings are slim. However, it is an easy place to clean because it is well away from the giant sea bass' giant mouth, which may employ suction to snack on the not very cautious cleaner. The kelp bass seemed to sneak up along the dorsal (top) region from behind, moving cautiously towards the head. They appeared more "nervous" as they approached it... if you will pardon my anthropomorphism here. The kelp bass hesitated, and often backed off without a tidbit after assessing the situation. When they did snatch a snack, they dove straight down towards it, and almost seemed to bounce off the sea bass like a Super Ball. They were out of there... and fast.

I noted that whenever a kelp bass was doing the cleaning, and grabbed a copepod munchie, the giant sea bass' mouth would open wide. I've never seen giant sea bass do that with any other cleaner fish. If I were watching black groupers in the Caribbean, I'd know they opened their mouth wide to allow various wrasses, shrimp and other cleaners to enter it and remove food particles from their teeth. Giant sea bass have no significant teeth in the forward part of their mouth. All I could hypothesize was that the sea bass knew kelp bass were one of the tastiest fish in our waters, and hoped they would venture close enough to make them a meal!

On Saturday noted marine artist and muralist Wyland was on board the King Neptune. Yes, like Cher, Spielberg, Sinatra and Dr. Bill, he only needs one name to establish his identity. Many of you know of him because of the incredible murals of whales he paints on buildings, walls and other structures around the world. I knew we had a number of associates in common, including Dr. Richard C. Murphy and Pam Stacey, formerly of The Cousteau Society (Wyland is a member of its board of directors); "her deepness," National Geographic Explorer Dr. Sylvia Earle; and Dr. Guy Harvey who I filmed the great white sharks with off Guadalupe Island. I went to talk to him, found Wyland to be very approachable, and spent a good part of my first two surface intervals talking with him and his staff from the Wyland Foundation in Laguna Beach.

Before our third dive (at Blue Car Wreck), Wyland asked if I'd jump in the water with him before the rest of the group, and be his dive buddy. He wanted to see the giant sea bass. I told him I was a jinx at that site, and no one who had dived there with me in the last month had seen the bass (while nearly everyone else on board did). He said we'd break the jinx on this dive. I followed his bubble trail down to a depth of nearly 90 feet, and we were treated to three passes by giant sea bass who wanted to see what the bubbles were all about. Despite poor visibility, a good current and low light as the sun "set" over the adjacent hillside, Wyland was ecstatic about the dive. He definitely had an artist's take on the dive conditions! Hmmm... I hope he decides to start painting these incredible "giant" fish in addition to his much larger whales and other marine mammals. Certainly he would do justice to this magnificent species! If not, I'll "settle" for renditions by our own Porschia Denning.

© 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!

Copepod parasites dominate the head region of a sea bass, rock wrasse cleaning bass near tail;
kelp bass cleaning bass near head, sea bass with mouth open after being cleaned by kelp bass.

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