DIVE DRY WITH DR. BILL #871: IT'S ELECTRIFYING
My son Kevin tells me that since he moved from California to Colorado, his electric bill has dropped substantially. As a single guy, my bill here on the island isn't too bad despite the high rates charged by Southern California Edison. However, I'm still looking for ways to reduce my bill through conservation and alternate energy options.
On a solo night dive a few years ago, I almost came in contact with such a source! As I ascended to the surface, I sensed something hovering above my head. I looked up and there it was... a torpedo or electric ray (Tetronarce californica or Torpedo californica depending on your taxonomist) a few feet above me. I applied my brakes and started shooting video of it. The ray followed me for several minutes before deciding I was neither threat nor treat.
I rarely see this unusual species in our dive park. However I often saw it when diving Farnsworth Bank, a submerged deep water pinnacle about 1 1/2 miles off the backside of the island. I'd often descend to 150-180 fsw there and would encounter several of them. On at least one dive, a group of them followed me up to the top of the pinnacle (about 60 fsw) but left me there as I ascended to my deco stop.
The Pacific electric ray bears a striking resemblance to the USS Enterprise of Star Trek fame. I think Rod Roddenberry, son of Gene, should incorporate its imagery in his dive club. At a maximum length of five feet, they are much smaller than the starship and incapable of warp speed. They are gray to blue-gray in color with black spots. The body is dorso-ventrally flattened (like a pancake) and somewhat round.
This species is found from Japan and northern British Columbia to the middle coast of Baja. In shallow water they are usually nocturnal and rest on the bottom, often partially buried, during daylight. Here they seem to prefer soft bottom habitats. They breathe through two rounded spiracles located behind the eyes. However in deep water like Farnsworth Bank they are often active during the day. They have been observed in waters as deep as 1,000 fsw.
Dr. Milton Love says individuals may live to be Sweet 16 or longer (and probably never been kissed, although it would be truly electrifying). Females tend to grow larger than males. Sexual maturity is reached at lengths ranging from 24 to 30 inches. I've never seen them mate nor have I read accounts of it by others, but mate they do... in the privacy of their own habitat! I can respect that. The young develop within the female's body and are born live.
As its name suggests, these rays generate electric shocks used to stun fish and other prey, and for defense. The organs responsible for this are located on the head. Milton says the electric shock produced by these fish is on the order of 45 volts or more. When capturing prey, the ray often envelopes it with its pectoral fins and delivers the shock.
Back in the 1980s, I was a consultant for a two hour documentary on the Channel Islands created by Jacques-Yves and Jean-Michel Cousteau for Turner Broadcasting. We were filming on board The Cousteau Society's incredible windship Alcyone. One of the team's divers, Clay Wilcox, saw an electric ray on a dive. He knew what it was and what it could do, but like many of us he had to see for himself. Needless to say it was a shocking experience and he was kept out of the water for a day to ensure it was safe to dive.
© 2020 Dr. Bill Bushing. For the entire archived set of over 850 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Images from my nocturnal encounter; torpedo ray on the bottom; one in shallow water and another deep off Farnsworth Bank.
My son Kevin tells me that since he moved from California to Colorado, his electric bill has dropped substantially. As a single guy, my bill here on the island isn't too bad despite the high rates charged by Southern California Edison. However, I'm still looking for ways to reduce my bill through conservation and alternate energy options.
On a solo night dive a few years ago, I almost came in contact with such a source! As I ascended to the surface, I sensed something hovering above my head. I looked up and there it was... a torpedo or electric ray (Tetronarce californica or Torpedo californica depending on your taxonomist) a few feet above me. I applied my brakes and started shooting video of it. The ray followed me for several minutes before deciding I was neither threat nor treat.
I rarely see this unusual species in our dive park. However I often saw it when diving Farnsworth Bank, a submerged deep water pinnacle about 1 1/2 miles off the backside of the island. I'd often descend to 150-180 fsw there and would encounter several of them. On at least one dive, a group of them followed me up to the top of the pinnacle (about 60 fsw) but left me there as I ascended to my deco stop.
The Pacific electric ray bears a striking resemblance to the USS Enterprise of Star Trek fame. I think Rod Roddenberry, son of Gene, should incorporate its imagery in his dive club. At a maximum length of five feet, they are much smaller than the starship and incapable of warp speed. They are gray to blue-gray in color with black spots. The body is dorso-ventrally flattened (like a pancake) and somewhat round.
This species is found from Japan and northern British Columbia to the middle coast of Baja. In shallow water they are usually nocturnal and rest on the bottom, often partially buried, during daylight. Here they seem to prefer soft bottom habitats. They breathe through two rounded spiracles located behind the eyes. However in deep water like Farnsworth Bank they are often active during the day. They have been observed in waters as deep as 1,000 fsw.
Dr. Milton Love says individuals may live to be Sweet 16 or longer (and probably never been kissed, although it would be truly electrifying). Females tend to grow larger than males. Sexual maturity is reached at lengths ranging from 24 to 30 inches. I've never seen them mate nor have I read accounts of it by others, but mate they do... in the privacy of their own habitat! I can respect that. The young develop within the female's body and are born live.
As its name suggests, these rays generate electric shocks used to stun fish and other prey, and for defense. The organs responsible for this are located on the head. Milton says the electric shock produced by these fish is on the order of 45 volts or more. When capturing prey, the ray often envelopes it with its pectoral fins and delivers the shock.
Back in the 1980s, I was a consultant for a two hour documentary on the Channel Islands created by Jacques-Yves and Jean-Michel Cousteau for Turner Broadcasting. We were filming on board The Cousteau Society's incredible windship Alcyone. One of the team's divers, Clay Wilcox, saw an electric ray on a dive. He knew what it was and what it could do, but like many of us he had to see for himself. Needless to say it was a shocking experience and he was kept out of the water for a day to ensure it was safe to dive.
© 2020 Dr. Bill Bushing. For the entire archived set of over 850 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Images from my nocturnal encounter; torpedo ray on the bottom; one in shallow water and another deep off Farnsworth Bank.
