DIVE DRY WITH DR. BILL #401: YOUR TRUE COLORS, GARY?
Most southern Californians and even a number of our non-diving out-of-state visitors recognize that the beautiful orange fish so prevalent in our waters is not a goldfish, but the State of California's salt water fish, the garibaldi (Hypsypops rubicundus). Some even recognize it is a member of the largely tropical and subtropical damselfish family (although there are both female and male "damsels!"). Like many divers, it prefers warmer waters... and the ocean off our island has been strangely "warm" during the winter and alternating between "cold" and "luke warm" this summer.
Even before summer officially began, I wondered how the unusual water temperatures were going to affect the garibaldi's mating season. Yes, like many critters, these poor fish have a defined time of year to mate and must pleasure themselves by "munching" the rest of the year. Spawning may begin as early as March and go through July or even as late as October. Scientists report it is triggered when the temperature reaches 59 F (15 C). Back in February I was recording temperatures that high or higher, and wearing my 3/2mm wetsuit! Then in June, July and even August I had temperatures at the same depth that were at times well below that.
It did seem that nest building activity began a little late this year, although I saw a few garibaldi off Santa Cruz Island with huge (5 to 6 ft diameter) nests in June. I didn't document it scientifically, but it appeared that fresh eggs were not being laid in the nests here until July this year. Too late to apply for a grant to study this using appropriate experimental methods. It seems I'm often a day late and a few thousand dollars short!
So, Dr. Bill, tell us more about the mating behavior of these intriguing fish. Glad you asked... but maybe you should buy my DVD about the garibaldi rather than getting all my vast knowledge for free! Well, I should at least tell you a little something about my dive buddy Gary Garibaldi and his friends. I've written previously about how these fish weed out algae and invertebrates from a spot on a rock in their territory. Then they let only certain species of red algae grow, creating a circular or oval shaped patch of red on the reef. Since red gets absorbed first in the water column, the nests at this stage look dark... until I shine my video lights on them and bring out their true colors (with apologies to Cyndi Lauper). At this stage there are no eggs in the nest and the garibaldi begins soliciting females to enter into his territory and lay their eggs.
More than one female may be enticed into the nest through a behavior known as "dipping." The little fellow swims in vertical circles... actually more oval in shape... and clicks to attract her attention. Yes, I know... sounds like what goes on with adolescent humans (regardless of age) near the land's end of our Pleasure Pier. The females are very selective in choosing a potential mate and in one study a lady garibaldi visited 15 different nests before mating with one of the male garibaldi. Sounds like the ladies I approach (although my odds and more like one in a million). Once the eggs are laid and fertilized, they appear bright yellow against the red nest. Many females may enter the nests of the more successful males, creating patches of eggs of different ages. A single female may lay up to 18,000 eggs, and will mate with several males. I shun such promiscuity.
Of course the "lucky" guy gets stuck with all the child care and vigorously defends his nest as the ladies lay more eggs and the ones already in the nest mature. As they do develop, the eggs turn gray (like many of us humans) and make the nest appear less attractive to the girls checking it out. The male may actually gobble up some of these older eggs to return the nest to the more attractive red color so he can entice more ladies in to see his etchings. Hmm... maybe I need to repaint my living room walls. So there you have it. Now you, too, can wow your friends by telling them about Gary's nest status next time you are snorkeling or SCUBA diving. Hope your friends don't yawn like mine do. If so, buy my "Damsels of SoCal" DVD and you can make sure they fall asleep!
Image caption: Early stage nest in red with Gary waiting for the ladies, nest with yellow eggs, developing young garibaldi inside eggs (from nest scraped by diver's equipment) and nest with old gray eggs showing bite marks from the male removing some.
Most southern Californians and even a number of our non-diving out-of-state visitors recognize that the beautiful orange fish so prevalent in our waters is not a goldfish, but the State of California's salt water fish, the garibaldi (Hypsypops rubicundus). Some even recognize it is a member of the largely tropical and subtropical damselfish family (although there are both female and male "damsels!"). Like many divers, it prefers warmer waters... and the ocean off our island has been strangely "warm" during the winter and alternating between "cold" and "luke warm" this summer.
Even before summer officially began, I wondered how the unusual water temperatures were going to affect the garibaldi's mating season. Yes, like many critters, these poor fish have a defined time of year to mate and must pleasure themselves by "munching" the rest of the year. Spawning may begin as early as March and go through July or even as late as October. Scientists report it is triggered when the temperature reaches 59 F (15 C). Back in February I was recording temperatures that high or higher, and wearing my 3/2mm wetsuit! Then in June, July and even August I had temperatures at the same depth that were at times well below that.
It did seem that nest building activity began a little late this year, although I saw a few garibaldi off Santa Cruz Island with huge (5 to 6 ft diameter) nests in June. I didn't document it scientifically, but it appeared that fresh eggs were not being laid in the nests here until July this year. Too late to apply for a grant to study this using appropriate experimental methods. It seems I'm often a day late and a few thousand dollars short!
So, Dr. Bill, tell us more about the mating behavior of these intriguing fish. Glad you asked... but maybe you should buy my DVD about the garibaldi rather than getting all my vast knowledge for free! Well, I should at least tell you a little something about my dive buddy Gary Garibaldi and his friends. I've written previously about how these fish weed out algae and invertebrates from a spot on a rock in their territory. Then they let only certain species of red algae grow, creating a circular or oval shaped patch of red on the reef. Since red gets absorbed first in the water column, the nests at this stage look dark... until I shine my video lights on them and bring out their true colors (with apologies to Cyndi Lauper). At this stage there are no eggs in the nest and the garibaldi begins soliciting females to enter into his territory and lay their eggs.
More than one female may be enticed into the nest through a behavior known as "dipping." The little fellow swims in vertical circles... actually more oval in shape... and clicks to attract her attention. Yes, I know... sounds like what goes on with adolescent humans (regardless of age) near the land's end of our Pleasure Pier. The females are very selective in choosing a potential mate and in one study a lady garibaldi visited 15 different nests before mating with one of the male garibaldi. Sounds like the ladies I approach (although my odds and more like one in a million). Once the eggs are laid and fertilized, they appear bright yellow against the red nest. Many females may enter the nests of the more successful males, creating patches of eggs of different ages. A single female may lay up to 18,000 eggs, and will mate with several males. I shun such promiscuity.
Of course the "lucky" guy gets stuck with all the child care and vigorously defends his nest as the ladies lay more eggs and the ones already in the nest mature. As they do develop, the eggs turn gray (like many of us humans) and make the nest appear less attractive to the girls checking it out. The male may actually gobble up some of these older eggs to return the nest to the more attractive red color so he can entice more ladies in to see his etchings. Hmm... maybe I need to repaint my living room walls. So there you have it. Now you, too, can wow your friends by telling them about Gary's nest status next time you are snorkeling or SCUBA diving. Hope your friends don't yawn like mine do. If so, buy my "Damsels of SoCal" DVD and you can make sure they fall asleep!
Image caption: Early stage nest in red with Gary waiting for the ladies, nest with yellow eggs, developing young garibaldi inside eggs (from nest scraped by diver's equipment) and nest with old gray eggs showing bite marks from the male removing some.
