DIVE DRY WITH DR. BILL #840: THE BIG HEAD
There is a section of the dive park I rarely go to, the shallows at the very end on the Descanso Beach side. Recently I've been weeding out the invasive "devil weed" (Sargassum horneri) in that area and it made me think back to a few years ago to the winter of 2013-14 when I also did repeated dives to the death-defying depth of 10-15 feet. Back then it wasn't to weed the seaweed, but to film a male cabezon (Scorpaenichthys marmoratus) sitting on its nest.
The cabezon is a true member of the sculpin family (Cottidae). Many divers are prone to call a somewhat similar looking fish, the spotted scorpionfish (Scorpaena guttata), a sculpin too.. but they are wrong (says the ex-spurt marine biologist)! Despite the similarity in their genus names, they are in the scorpionfish (aka rockfish) family. Apparently the cabezon got its common name from a Spanish friar who was head of the Mission San Buenaventura according to Dr. Milton Love. It means "big-headed."
They are found from SE Alaska down to central Baja California. According to Milton they can be found in a variety of habitats from rocky reefs to oil rigs to interfaces between rocks and mud bottoms. Although the ones I've seen in Catalina waters are generally shallow, they may be found much deeper.
Perhaps I could nickname them Christmas fish since they are usually red, green or... brown (as in my dead Christmas tree). The body also is mottled in darker colors. One study suggested that males were usually red and females green, but that has not been substantiated in other studies. There are skin flaps above the mouth and the ears. And, of course, the "big head" is another give away.
Now one year I spent a lot of time with a male cabezon tending its nest in the shallows. Yes, the females of this species are quite liberated... once they've laid their "clutch" of up to 150,000 eggs. papa gets stuck with child care. Although spawning may occur year-round, it peaks during winter in SoCal. Eggs may be many different colors including white, pink, crimson (go Harvard!) or blue-green. Don't eat them though... they are poisonous to humans and other potential predators. Depending on water temperature, the eggs may take up to about 50 days to hatch. At that point papa cabezon is freed from child-rearing duties.
The little "cabbie" larvae may drift for as long as 3-4 months before settling down. I guess they want to get as far from Mom and Dad as they can. They are about 1-2" long when they finally settle out. I was able to sample a few eggs from the nest at two different stages. This was before the MPA was established of course. I trained my powerful microscope on them to provide you with the accompanying images. Cabezon may live for as long as 20 years. They may reach lengths in excess of three feet and weights up to at least 25 pounds.
Initially the youngsters feed on small crusteaceans. Later they add crabs, lobster, fish and molluscs (including nudibranchs, clams, and octopus) to their diet. A number of fish, birds and marine mammals prey on them. Although Native Americans ate them, it seems European explorers and settlers were not so keen about them. Perhaps it was the blue color of the flesh. More recently they were considered a good food fish as the flesh is tasty (not that I've tried it!).
© 2019 Dr. Bill Bushing. For the entire archived set of over 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Papa cabezon giving me the evil eye.
Image caption: Papa cabezon perched on nest of greenish eggs, and the eggs under the microscope at two stages in their development.
There is a section of the dive park I rarely go to, the shallows at the very end on the Descanso Beach side. Recently I've been weeding out the invasive "devil weed" (Sargassum horneri) in that area and it made me think back to a few years ago to the winter of 2013-14 when I also did repeated dives to the death-defying depth of 10-15 feet. Back then it wasn't to weed the seaweed, but to film a male cabezon (Scorpaenichthys marmoratus) sitting on its nest.
The cabezon is a true member of the sculpin family (Cottidae). Many divers are prone to call a somewhat similar looking fish, the spotted scorpionfish (Scorpaena guttata), a sculpin too.. but they are wrong (says the ex-spurt marine biologist)! Despite the similarity in their genus names, they are in the scorpionfish (aka rockfish) family. Apparently the cabezon got its common name from a Spanish friar who was head of the Mission San Buenaventura according to Dr. Milton Love. It means "big-headed."
They are found from SE Alaska down to central Baja California. According to Milton they can be found in a variety of habitats from rocky reefs to oil rigs to interfaces between rocks and mud bottoms. Although the ones I've seen in Catalina waters are generally shallow, they may be found much deeper.
Perhaps I could nickname them Christmas fish since they are usually red, green or... brown (as in my dead Christmas tree). The body also is mottled in darker colors. One study suggested that males were usually red and females green, but that has not been substantiated in other studies. There are skin flaps above the mouth and the ears. And, of course, the "big head" is another give away.
Now one year I spent a lot of time with a male cabezon tending its nest in the shallows. Yes, the females of this species are quite liberated... once they've laid their "clutch" of up to 150,000 eggs. papa gets stuck with child care. Although spawning may occur year-round, it peaks during winter in SoCal. Eggs may be many different colors including white, pink, crimson (go Harvard!) or blue-green. Don't eat them though... they are poisonous to humans and other potential predators. Depending on water temperature, the eggs may take up to about 50 days to hatch. At that point papa cabezon is freed from child-rearing duties.
The little "cabbie" larvae may drift for as long as 3-4 months before settling down. I guess they want to get as far from Mom and Dad as they can. They are about 1-2" long when they finally settle out. I was able to sample a few eggs from the nest at two different stages. This was before the MPA was established of course. I trained my powerful microscope on them to provide you with the accompanying images. Cabezon may live for as long as 20 years. They may reach lengths in excess of three feet and weights up to at least 25 pounds.
Initially the youngsters feed on small crusteaceans. Later they add crabs, lobster, fish and molluscs (including nudibranchs, clams, and octopus) to their diet. A number of fish, birds and marine mammals prey on them. Although Native Americans ate them, it seems European explorers and settlers were not so keen about them. Perhaps it was the blue color of the flesh. More recently they were considered a good food fish as the flesh is tasty (not that I've tried it!).
© 2019 Dr. Bill Bushing. For the entire archived set of over 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Papa cabezon giving me the evil eye.
Image caption: Papa cabezon perched on nest of greenish eggs, and the eggs under the microscope at two stages in their development.
