DIVE DRY WITH DR. BILL #795: WHILE MY GUITARFISH GENTLY WEEPS
Anyone who really knows me is aware that although I greatly enjoy music, I have absolutely no talent at it. My junior high school band director asked me to just move my trombone slide up and down as we marched in the Fourth of July parade and not to blow into the mouthpiece. Later, when I moved to Catalina in 1969, the seaplanes "lost" the guitar I had purchased when I traded in my trombone so I never got much chance to play it.
But my columns aren't focused on music since I dive in the "Silent World." Yes, it actually is fairly noisy and I occasionally hear the theme from "Jaws" while submerged. However, my focus is on the critters themselves and today is no exception. I'm going to reminisce about the first dive I ever did off Catalina back on August 24, 1969, out near Arrow Point on the West End.
Prior to moving here, I was unaware one needed to be certified to get tanks filled in California. We didn't need no stinking certification back in the fresh waters around Chicago! The headmaster at the Catalina Island School (Toyon Bay) informed me of this requirement and a trustee at the school arranged for me to get "edumacated" through the Aquatic Center in Newport Beach under the guidance of legendary instructor Ron Merker. As a young "know it all scientist," I guess I asked a lot of questions of Ron. Ron often looked (and acted) like a Marine drill instructor and would respond by making me drop on all fours to receive his "answer." He was a great instructor and I attribute my good training largely to him and the Los Angeles County program.
After the pool work, our open water check-out dives were scheduled on board the "Golden Doubloon" dive boat. Originally owned by treasure hunter Mel Fisher, it was the first of the southern California charter dive boats and operated out of the 22nd Street Landing. I came on board the night before and awoke in the morning off Catalina. I went up to the deck and saw the island for the first time, remarking how much it looked like the Greek Islands I had free dived off of the summer before.
This was my very first SCUBA dive in salt water. I did my giant stride and descended with my dive buddy, another member of Ron's Los Angeles County certification class. As we submerged, I was startled by something swimming down past me. No, it wasn't my buddy... it was a shovelnose guitarfish (Rhinobatos productus). Although a distant cousin of sharks including the great white, it posed no threat to me as long as it recognized I wasn't a crab, shrimp, clam or worm! They lack the stingers of their ray relatives. They have a SoCal relative, the banded guitarfish (Zapteryx exasperata) which I've never seen in Catalina waters but can be encountered off the mainland shores.
The shovelnose has a pointed snout and a body that is flattened top-to-bottom. The head is nearly triangular in shape and the elongated body with its thick tail makes it appear like a guitar, although not quite a Fender Stratocaster. They may reach a weight of over 20 pounds and lengths of four to more than five feet with females being somewhat larger than males. There is a row of spines down the back. Body color may be gray, olive or brown to help them camouflage against the bottom. This guitarfish swims using its tail rather than their pectoral fins like many other rays.
They are generally found over soft bottoms in less than 40 ft of water. Their mouths are on the underside of the body. Because of this they do not "mouth breathe," but take oxygen-containing water in through holes called spiracles on the upper body surface and expel it through gills on the underside.
Guitarfish are ambush predators. They may bury into the soft substrate and wait for munchables to approach. When it does, the fish lunges out in a cloud of dust (but no high ho Silver) and grabs breakfast, lunch or dinner. Their chompers are more like human molars and are adapted to crushing their food. They tend to be more active after the sun goes down. In turn sharks such as leopards prey on them
I know you've been waiting for the sex (er, reproduction) section of this column. Well, I don't want to disappoint my readers! These rays are sexually mature at the precocious age of 7 or 8 years. Females give live birth to their brood of 6 to 28 pups in protected bays during early summer after a year of gestation. Shortly after, the boys arrive to mate. I guess they want to keep their ladies pregnant and bare finned.
© 2019 Dr. Bill Bushing. For the entire archived set of over 750 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Shovelnose guitarfish swimming off the bottom; head region and spiracles (arrow).
Anyone who really knows me is aware that although I greatly enjoy music, I have absolutely no talent at it. My junior high school band director asked me to just move my trombone slide up and down as we marched in the Fourth of July parade and not to blow into the mouthpiece. Later, when I moved to Catalina in 1969, the seaplanes "lost" the guitar I had purchased when I traded in my trombone so I never got much chance to play it.
But my columns aren't focused on music since I dive in the "Silent World." Yes, it actually is fairly noisy and I occasionally hear the theme from "Jaws" while submerged. However, my focus is on the critters themselves and today is no exception. I'm going to reminisce about the first dive I ever did off Catalina back on August 24, 1969, out near Arrow Point on the West End.
Prior to moving here, I was unaware one needed to be certified to get tanks filled in California. We didn't need no stinking certification back in the fresh waters around Chicago! The headmaster at the Catalina Island School (Toyon Bay) informed me of this requirement and a trustee at the school arranged for me to get "edumacated" through the Aquatic Center in Newport Beach under the guidance of legendary instructor Ron Merker. As a young "know it all scientist," I guess I asked a lot of questions of Ron. Ron often looked (and acted) like a Marine drill instructor and would respond by making me drop on all fours to receive his "answer." He was a great instructor and I attribute my good training largely to him and the Los Angeles County program.
After the pool work, our open water check-out dives were scheduled on board the "Golden Doubloon" dive boat. Originally owned by treasure hunter Mel Fisher, it was the first of the southern California charter dive boats and operated out of the 22nd Street Landing. I came on board the night before and awoke in the morning off Catalina. I went up to the deck and saw the island for the first time, remarking how much it looked like the Greek Islands I had free dived off of the summer before.
This was my very first SCUBA dive in salt water. I did my giant stride and descended with my dive buddy, another member of Ron's Los Angeles County certification class. As we submerged, I was startled by something swimming down past me. No, it wasn't my buddy... it was a shovelnose guitarfish (Rhinobatos productus). Although a distant cousin of sharks including the great white, it posed no threat to me as long as it recognized I wasn't a crab, shrimp, clam or worm! They lack the stingers of their ray relatives. They have a SoCal relative, the banded guitarfish (Zapteryx exasperata) which I've never seen in Catalina waters but can be encountered off the mainland shores.
The shovelnose has a pointed snout and a body that is flattened top-to-bottom. The head is nearly triangular in shape and the elongated body with its thick tail makes it appear like a guitar, although not quite a Fender Stratocaster. They may reach a weight of over 20 pounds and lengths of four to more than five feet with females being somewhat larger than males. There is a row of spines down the back. Body color may be gray, olive or brown to help them camouflage against the bottom. This guitarfish swims using its tail rather than their pectoral fins like many other rays.
They are generally found over soft bottoms in less than 40 ft of water. Their mouths are on the underside of the body. Because of this they do not "mouth breathe," but take oxygen-containing water in through holes called spiracles on the upper body surface and expel it through gills on the underside.
Guitarfish are ambush predators. They may bury into the soft substrate and wait for munchables to approach. When it does, the fish lunges out in a cloud of dust (but no high ho Silver) and grabs breakfast, lunch or dinner. Their chompers are more like human molars and are adapted to crushing their food. They tend to be more active after the sun goes down. In turn sharks such as leopards prey on them
I know you've been waiting for the sex (er, reproduction) section of this column. Well, I don't want to disappoint my readers! These rays are sexually mature at the precocious age of 7 or 8 years. Females give live birth to their brood of 6 to 28 pups in protected bays during early summer after a year of gestation. Shortly after, the boys arrive to mate. I guess they want to keep their ladies pregnant and bare finned.
© 2019 Dr. Bill Bushing. For the entire archived set of over 750 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Shovelnose guitarfish swimming off the bottom; head region and spiracles (arrow).
