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Dive Dry with Dr. Bill

#704: A Giant Among Kelpfish

Due to my surgery, I'm marooned here on land and won't be able to dive for some time. This will be my longest "drought" in about two decades. The longer I remain topside, the more I think I may need a "refresher course" to regain my SCUBA skills. Fortunately several instructors have offered to conduct it and a few have even offered to carry my gear into the water for me. It would be nice to have a few dive sherpas!

I had written a column about the underwater sculptures placed in the dive park, but the artist asked me to hold it until the official release date on December 4th. I wrote a second column, but wasn't pleased with it. So I'm relegated to looking through my old images to come up with topics for these columns. Good thing I have over 200,000 images stored in my computer. Bad thing is I'll have trouble going through them to select each week's subject. The deadline for submission is tomorrow morning, so here goes.

I've written about giant kelpfish (Heterostichus rostratus) in the past, but they are an intriguing species worthy of more PR. They have proven more adaptable than many of our other local fish species. The loss of giant kelp (after which they were named!) and the dominance of the invasive Asian seaweed Sargassum horneri has impacted many local species. The giant kelpfish early on began using the exotic seaweed to hide in and even to nest in. A bit of a traitor IMHO, but adaptation is critical in a changing environment.

Giant kelpfish are known from British Columbia to the tip of Baja, although they are less common above Pt. Conception. Apparently they are restricted to the same depth range as a recreational SCUBA diver (about 130 ft). I don't remember ever seeing one on my deep dives to 200 ft. I guess they never achieved a tech diver's certification. Hmmm... neither did I!

Dr. Milton Love writes that these fish come in three colors: green, red and brown. I have also seen ones that are bright yellow. He also lists four different patterns: plain, barred, striped and mottled. Their pattern may change within seconds, especially when defending territory or mating. My face usually turns red when just thinking about the second activity.

Males tend to be green or brown, which usually matches the green and brown algae I've seen them nest in. Females are more fashionable and may adopt any of the three colors. Color changes more slowly than pattern, possibly on the order of weeks rather than seconds.

Females may live longer than males whose lifespans are generally limited to five years. Of course this may be due to the fact that the male assumes the duty of guarding the nest and defending the eggs from potential predators. Spawning occurs year-round which sounds much more enjoyable than the seasonal mating of garibaldi and other fish.

It has been stated that the eggs of a single female are laid in the male's algal nest. However I have observed more than one female in a single nest at the same time. The eggs adhere to the algae. One researcher found that the eggs they observed were either brown or red. The ones I've observed were all white. Perhaps my eyes couldn't see the brown or red ones against the algal nest.

When the female finishes laying her eggs in the male's nest, he chases her away. I've watched (and filmed) males nipping at the tail of the female to drive her off. I found that interesting since I've seen male garibaldi do the same thing. The male garibaldi solicits several females into his nest and the tail biting often occurs when a new female tries to eat the eggs of a previous paramour.

Years ago I located a lonely male in his nest of brown algae. I visited him on many dives and he apparently became acclimated to my presence. If I held out my hand palm-up, he would occasionally swim over to and rest in it. I was even able to gently stroke its sides. I think he was pretty bored after days of child care!

© 2016 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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Various color and pattern variations in the giant kelpfish.

This document maintained by Dr. Bill Bushing.
Material and images © 2016 Star Thrower Educational Multimedia