DIVE DRY WITH DR. BILL #793: AIN'T GOT THE BLUES
Back when I was teaching at a boarding school on Catalina Island, the cafeteria was closed to us teachers during the summer. I had to fend for myself. That was not a great strategy as my culinary skills were quite limited. I wasn't fond of "wild boar" or goat so I rarely hunted for them except for ecological control reasons. I did like venison but our local deer were off limits to me. However, I could fish and often used my old boat "Eleutheria" (Freedom) to catch yummy sand dabs and "rock cod" from deep holes off the island's coast.
Now rock cod are a member of the rockfish or scorpionfish family (Scorpaenidae). They aren't really cod. This family is quite large with well over 400 individual species. There are some 85 of these found along the Pacific coast. Although some are deep and beyond my diving depths, others are more shallow and are often observed in recreational diving depths Within Catalina waters I have seen many different species. The kelp rockfish (Sebastes atrovirens) is the most commonly observed one, but I have also seen brown, gopher, copper, black-and-yellow, starry, China, grass, and rosy rockfish as well as bocaccio and chilipepper. Some of those were only seen at depths approaching 200 feet.
One rockfish I don't ever remember seeing in Catalina waters is the blue rockfish (Sebastes mystinus). We are within its geographic range from SE Alaska to northern Baja California, although they are most common only down to about Pt. Conception. They have no trouble adapting to waters as deep as 1,800 ft! I do!! I have filmed them in the colder waters off San Miguel Island, but those images are of limited value. Therefore I resorted to using two photos taken by my image savior, underwater photographer extraordinaire Kevin Lee so you can see the detail on the fish.
Dr. Milton Love in his magnificent tome, Certainly More Than You Want to Know About the Fishes of The Pacific Coast, indicates that molecular biologists have determined that the blue rockfish is actually two different species. These DNA hounds are certainly turning the taxonomic world upside-down. I fear that were I to live another 50 years, all of the species I currently know would be called something else. My brain only has room for two names per species, the scientific and common ones!
The two species of "blues" have slightly different body pigmentation. One has blotchy coloration on the sides while the other is a more uniform and often darker blue with a more obvious lateral line. The latter is also more slender while the former has a deeper body. I guess one group tried Jenny Craig while the other chowed down on higher caloric value foods... or at least larger helpings! Both young and old focus on critters found in the water column like zooplanktonic crustaceans, jellies and worms. Larger individuals add smaller fishes and squid to their diet.
Rockfish utilize internal fertilization but it is rarely observed on our coast. I guess they prefer their privacy, or the depths at which they may be found prohinbit most divers from becoming Peeping Toms. Although some are sexually mature at the young age of 4-5 years and about nine inches, all finally reach that stage at 9-11 years and about 14 inches. A fecund female may release over half a million eggs, mostly during the winter months.
The larvae remain in the plankton for as long as half a year before settling out in late spring and early summer. These youngsters pretty much remain within recreational diving depths (< 130 feet). Adults may live more than 40 years and form huge schools numbering in the thousands. I just hope they don't have to deal with Common Core Math. I had no trouble with calculus but I have great difficulty understanding my granddaughter Allison's math homework.
© 2018 Dr. Bill Bushing. For the entire archived set of nearly 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Two images of blue rockfish from San Miguel Island and two taken by photographer Kevin Lee.
Back when I was teaching at a boarding school on Catalina Island, the cafeteria was closed to us teachers during the summer. I had to fend for myself. That was not a great strategy as my culinary skills were quite limited. I wasn't fond of "wild boar" or goat so I rarely hunted for them except for ecological control reasons. I did like venison but our local deer were off limits to me. However, I could fish and often used my old boat "Eleutheria" (Freedom) to catch yummy sand dabs and "rock cod" from deep holes off the island's coast.
Now rock cod are a member of the rockfish or scorpionfish family (Scorpaenidae). They aren't really cod. This family is quite large with well over 400 individual species. There are some 85 of these found along the Pacific coast. Although some are deep and beyond my diving depths, others are more shallow and are often observed in recreational diving depths Within Catalina waters I have seen many different species. The kelp rockfish (Sebastes atrovirens) is the most commonly observed one, but I have also seen brown, gopher, copper, black-and-yellow, starry, China, grass, and rosy rockfish as well as bocaccio and chilipepper. Some of those were only seen at depths approaching 200 feet.
One rockfish I don't ever remember seeing in Catalina waters is the blue rockfish (Sebastes mystinus). We are within its geographic range from SE Alaska to northern Baja California, although they are most common only down to about Pt. Conception. They have no trouble adapting to waters as deep as 1,800 ft! I do!! I have filmed them in the colder waters off San Miguel Island, but those images are of limited value. Therefore I resorted to using two photos taken by my image savior, underwater photographer extraordinaire Kevin Lee so you can see the detail on the fish.
Dr. Milton Love in his magnificent tome, Certainly More Than You Want to Know About the Fishes of The Pacific Coast, indicates that molecular biologists have determined that the blue rockfish is actually two different species. These DNA hounds are certainly turning the taxonomic world upside-down. I fear that were I to live another 50 years, all of the species I currently know would be called something else. My brain only has room for two names per species, the scientific and common ones!
The two species of "blues" have slightly different body pigmentation. One has blotchy coloration on the sides while the other is a more uniform and often darker blue with a more obvious lateral line. The latter is also more slender while the former has a deeper body. I guess one group tried Jenny Craig while the other chowed down on higher caloric value foods... or at least larger helpings! Both young and old focus on critters found in the water column like zooplanktonic crustaceans, jellies and worms. Larger individuals add smaller fishes and squid to their diet.
Rockfish utilize internal fertilization but it is rarely observed on our coast. I guess they prefer their privacy, or the depths at which they may be found prohinbit most divers from becoming Peeping Toms. Although some are sexually mature at the young age of 4-5 years and about nine inches, all finally reach that stage at 9-11 years and about 14 inches. A fecund female may release over half a million eggs, mostly during the winter months.
The larvae remain in the plankton for as long as half a year before settling out in late spring and early summer. These youngsters pretty much remain within recreational diving depths (< 130 feet). Adults may live more than 40 years and form huge schools numbering in the thousands. I just hope they don't have to deal with Common Core Math. I had no trouble with calculus but I have great difficulty understanding my granddaughter Allison's math homework.
© 2018 Dr. Bill Bushing. For the entire archived set of nearly 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Two images of blue rockfish from San Miguel Island and two taken by photographer Kevin Lee.
