DIVE DRY WITH DR. BILL #781: THEY AIN'T BASS AND THEY AIN'T (ALL) BLACK!
When I first moved to SoCal nearly 50 years ago, I heard tales about a mystery fish that was being decimated in California waters. In fact the instructor from whom I got my first certification, Ron Merker at the Newport Beach Aquatic Center, very briefly held a world record class fish he speared in 1953. There is a well known photo of Ron with the giant in the back of his MG sports car.
These gentle giants (as I call them) form courting and mating aggregations in shallow waters during late spring to early fall. Perhaps one of the reasons I never saw one in my early years here was that most of my diving was during the school year when I taught marine biology. During the summer, when I wasn't teaching, I spent much of the time exploring the island in my old Willys M-38 A1 military jeep.
Yep, I'm referring to the giant sea "bass" (Stereolepis gigas). For years they were called black sea bass, but that common name is more appropriately applied to an Atlantic species, Centropristis striata. Others have recently designated them the giant black sea bass. Perhaps that is a little better, but they aren't even bass (family Serranidae)... or even grouper (family Epinephelidae, although some still list grouper as a subfamily of the bass). They are in the wreckfish family (Polyprionidae) so maybe we should be referring to them as giant sea wreckfish!
To add insult to injury, although some of them are indeed black (or at least very dark in pigmentation) many are not. Fish caught on hand lines and by spearfishers were often very dark when brought in to the weigh scales in Avalon... but these fish were dead! Living individuals can occasionally be very dark in color too, but I find them to be the exception rather than the rule.
Pigmentation patterns in this species vary a fair bit. One can find bright silvery individuals that are at the opposite end of the grey scale from "black." Others are counter-shaded with darker dorsal surfaces and lighter ventral surfaces. Predators such as great white sharks approaching from above see a dark object against the dark rocky reef or kelp forest. When the gentle giant is in midwater, predators looking up at them see a light color that blends in with the sky. These different body patterns are referred to as morphotypes, or variants within a species.
I looked at my thousands of images of these incredible fish to find representatives of each pattern. The one that seemed most common was the spotted variety. Sometimes a light colored body with faint darker spots but usually a somewhat darker body with dark black spots. Hmmm... based on that, perhaps these incredible critters should be called giant polka-dotted sea wreckfish! Now doesn't that sound a lot better than giant black sea bass?
Okay, while we're at it, let's throw another wrench in the works. Body pigmentation in this species is not static. These fish can change their body coloration and spotting somewhat at will. On a few occasions I've seen them change within less than a minute! Perhaps I shouldn't refer to them as morphotypes due to this. True morphotypes tend to be based on fixed morphological characteristics, whereas these are plastic and change.
I have to ask my fellow SCUBA divers to cast away all those false notions from years past! Please be politically correct when you refer to our gentle giants! After all, how would my fellow human beings or Homo sapiens in the family Hominidae like to be mis-categorized in the primate family Lemuridae with the true lemurs. On second thought, emcee extraordinaire at our annual harbor clean-up, T. J. Jones, might get a chuckle out of that!
© 2018 Dr. Bill Bushing. For the entire archived set of over 775 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Instructor Ron Merker with 1953 record fish and a truly black giant "black" sea bass; one with light body color and a counter-shaded individual; and two of what I feel are the most common "morphotypes" with dark spots.
When I first moved to SoCal nearly 50 years ago, I heard tales about a mystery fish that was being decimated in California waters. In fact the instructor from whom I got my first certification, Ron Merker at the Newport Beach Aquatic Center, very briefly held a world record class fish he speared in 1953. There is a well known photo of Ron with the giant in the back of his MG sports car.
These gentle giants (as I call them) form courting and mating aggregations in shallow waters during late spring to early fall. Perhaps one of the reasons I never saw one in my early years here was that most of my diving was during the school year when I taught marine biology. During the summer, when I wasn't teaching, I spent much of the time exploring the island in my old Willys M-38 A1 military jeep.
Yep, I'm referring to the giant sea "bass" (Stereolepis gigas). For years they were called black sea bass, but that common name is more appropriately applied to an Atlantic species, Centropristis striata. Others have recently designated them the giant black sea bass. Perhaps that is a little better, but they aren't even bass (family Serranidae)... or even grouper (family Epinephelidae, although some still list grouper as a subfamily of the bass). They are in the wreckfish family (Polyprionidae) so maybe we should be referring to them as giant sea wreckfish!
To add insult to injury, although some of them are indeed black (or at least very dark in pigmentation) many are not. Fish caught on hand lines and by spearfishers were often very dark when brought in to the weigh scales in Avalon... but these fish were dead! Living individuals can occasionally be very dark in color too, but I find them to be the exception rather than the rule.
Pigmentation patterns in this species vary a fair bit. One can find bright silvery individuals that are at the opposite end of the grey scale from "black." Others are counter-shaded with darker dorsal surfaces and lighter ventral surfaces. Predators such as great white sharks approaching from above see a dark object against the dark rocky reef or kelp forest. When the gentle giant is in midwater, predators looking up at them see a light color that blends in with the sky. These different body patterns are referred to as morphotypes, or variants within a species.
I looked at my thousands of images of these incredible fish to find representatives of each pattern. The one that seemed most common was the spotted variety. Sometimes a light colored body with faint darker spots but usually a somewhat darker body with dark black spots. Hmmm... based on that, perhaps these incredible critters should be called giant polka-dotted sea wreckfish! Now doesn't that sound a lot better than giant black sea bass?
Okay, while we're at it, let's throw another wrench in the works. Body pigmentation in this species is not static. These fish can change their body coloration and spotting somewhat at will. On a few occasions I've seen them change within less than a minute! Perhaps I shouldn't refer to them as morphotypes due to this. True morphotypes tend to be based on fixed morphological characteristics, whereas these are plastic and change.
I have to ask my fellow SCUBA divers to cast away all those false notions from years past! Please be politically correct when you refer to our gentle giants! After all, how would my fellow human beings or Homo sapiens in the family Hominidae like to be mis-categorized in the primate family Lemuridae with the true lemurs. On second thought, emcee extraordinaire at our annual harbor clean-up, T. J. Jones, might get a chuckle out of that!
© 2018 Dr. Bill Bushing. For the entire archived set of over 775 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Instructor Ron Merker with 1953 record fish and a truly black giant "black" sea bass; one with light body color and a counter-shaded individual; and two of what I feel are the most common "morphotypes" with dark spots.
