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Dive Dry with Dr. Bill

#550: The Battle of the Beasts

On Sunday I grabbed my SCUBA and video gear, jumped in the Dr. Bill Mobile (my Yamaha golf cart) and headed down toward the Casino Point dive park for yet another night dive. I saw the flashing lights from emergency vehicles on the road and just before I got to the Casino and deputy stopped me. Some kids had tried to climb the steep slope there and were being retrieved by Search and Rescue. Obviously these numbskulls were not geologists... the quart diorite porphyry at this end of the island is highly fragmented and not a stable rock type for such exploits. Still, I didn't see why the entire road needed to be closed.

The next day the road was clear and I was able to get another nice 80 minute dive at the park. I was all alone in the water, but a group of visitors were shouting "Shark Week! Shark Week!" as I descended the stairs and entered the water. I guess some people actually believe the nonsense broadcast by The Discovery Channel. They should worry far more about cows or bees or dogs. You don't watch "Shark Week," do you? Heck, I don't even watch television (including my own cable TV show).

Of course there are vicious killers in our waters at night... if you happen to be a poor blacksmith, kelp surfperch or other small fish. I'm referring to the morays and kelp bass that take advantage of my video lights to snag several of these hapless munchables. The kelp bass have certainly learned how to take advantage of my brilliance (well, that of my lights at least) to locate and gulp down the tasty relatives of the garibaldi and other prey. But over the years I've learned that the nocturnal hunting patterns are less individualistic and random than I initially thought.

One of the things I've noticed this summer is how the kelp bass take advantage of the morays. Once the eels leave the shelter of the reef and venture out in the open to hunt, they are often joined by several kelp bass who follow them. When the moray flushes out a blacksmith by squeezing through the crevices and under rocks, a hungry bass often makes a stab at the fleeing fish. On my dives both here and in the tropics, I've often observed and filmed predators hiding behind another, less aggressive fish to take advantage of prey that aren't afraid of the partner. We biologists call this "shadowing." I'm not entirely sure the term applies when a hungry kelp bass follows another hungry predator, but I'm going to use it anyway.

Now this relationship is not always in one direction. I've watched as kelp bass hunt the blacksmith trying to shelter and catch a nap in the rocky reef at night. Frequently they miss their target and the poor damsel fish takes off running... er, finning. On several occasions I've watched as a waiting moray snaps it up. Twice the blacksmith literally fled right into the moray's mouth... not a good hiding place unless you need it for eternity.

Some of the funniest moments I experience while filming at night are when kelp bass try to take on something too big for their britches... er, mouths. Two summers ago I filmed as a small kelp bass tried to swallow a large blacksmith. It struggled with it while the blacksmith kept flipping its tail and trying to extricate itself. Finally the bass had to admit defeat and release its intended meal. Apparently some kelp bass have far bigger egos than mouths! Others should take a remedial fish identification class. I've watched as they've tried to take halfmoon (Catalina blue "perch") and opaleye (button back "perch") much larger than they could swallow. My mother used to say the same about me at the all-you-can-eat buffets. In fact, I beat the record held by a former L. A. Laker at Marmac's prime rib buffet... 18 servings plus deserts!

On several occasions I've also observed a quite different relationship between the hungry predators. I've watched as a moray hiding in the reef twitches and draws the attention of a kelp bass. On two occasions the kelp bass attempted to swallow the moray, grabbing it by the head. The moray then turned and bit the bass. That's what I call a stalemate. Once I even filmed a kelp bass try to capture a moray out in the open. I'm not sure which species was more confused by the interaction. I prefer to eat lower on the food chain... those nice juicy herbivores and primary producers. I promised sharks years ago I wouldn't eat them if they left me alone. So far, so good!

© 2013 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Kelp bass with juicy blacksmith in its mouth, two kelp bass "shadowing" a moray as it hunts;
moray biting kelp bass on the snout and kelp bass attempting to capture and swallow a moray.

This document maintained by Dr. Bill Bushing.
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