DIVE DRY WITH DR. BILL #785: LOOK UP TO THE HEAVENS
I rarely think back to my youth in the Chicago suburbs during the 1950s... that's much too much time travel for me. However, writing this week's column drew me back to 1957 when the Russians launched Sputnik into the sky. I bought my first telescope back then, a 4 1/4" Criterion Dynascope and with several friends formed the Northbrook Junior Astronomical Society. To this day I still own two telescopes, an 8" Celestron and a 13 1/2" Dobsonian.
Oh, wait, this is my marine biology column... not an astronomy one! However, as John Steinbeck wrote in The Log from the Sea of Cortez, "It is advisable to look from the tide pool to the stars and then back to the tide pool again." Of course John was putting into more palatable language the thoughts of his good friend, marine biologist Edward F. "Doc" Ricketts whose philosophical writings were full of gems (but torturous reading!).
Today's column focuses on another species which looks to the heavens... from the shallows of the ocean. I'm referring to the stargazers in the Uranoscopidae fish family. Although there are over 50 species in this group with distributions all over the world, I am very confident the one I filmed in the Philippines is the white margin stargazer (Uranoscopus sulphureus). Although it was initially buried in the sediment, our guide teased it out into the water column where I could see the white margins on the fins and the black spot on the first dorsal fin which are diagnostic characteristics. You can also see the smaller spots on the head and body. This species is known from the Indo-Pacific including the Red Sea, Indonesia, Australia, Fiji and Tonga in shallow water to depths of about 300 fsw.
Now if I were buried under the sand, I might experience some difficulty breathing... unless I had a SCUBA tank with me! The stargazer has adaptations to avoid intaking sediment when it pumps water past its gills. There are cirri (not to be confused with Siri) along the edge of the mouth to help filter the intake as well as a respiratory valve inside the lower jaw..
These fish are "anglers" and possess an extension from the lower lip often referred to as a lure to attract fish and invertebrates to the munching end of the stargazer. The upward-facing eyes and large mouth enhance its ability to capture food. Lying mostly buried in the sand, the unwary prey often doesn't notice this ambush and suction predator and becomes a victim... er, munchie. Menu items include fish and invertebrates such as crabs, octopus and squid.
I was surprised to discover in my research that many stargazers including this species possess several lines of defense in addition to burying themselves. I was unaware at the time that their pectoral fins have toxic spines and can inflict serious injury on humans and other predators. Yet in some parts of the world these fish are considered a delicacy and the poison in their spines is not toxic if cooked and eaten. In addition, they possess electric organs that can generate up to 50 volts to zap the unsuspecting with voltage depending on water temperature. The electric discharges may also be used to stun prey.
Apparently little is known about their reproduction. I did find a source that indicates they breed in spring and summer. No gory details thankfully. The female lays her eggs on the bottom. They later float to the surface and eventually hatch out as larvae. Once they are about one-half inch long they settle to the bottom and live out their lives there.
Two years after my trip to the Philippines, I was diving in the Egyptian Red Sea at Serib Kebir. As we entered the shallows, our group came across what I believed was another stargazer. I began filming it but our guide signalled to be cautious. This fish was almost completely buried like the stargazers with only its eyes and mouth visible. After we reached the beach, the guide told us it was a stonefish (probably Synanceia verrucosa). Good thing I didn't venture too close as they are thought to be the world's most venomous fish!
© 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: Whitemargin stargazer in "flight" and stargazers buried in the substrate with a stonefish (lower right) for comparison.
View attachment 486501
I rarely think back to my youth in the Chicago suburbs during the 1950s... that's much too much time travel for me. However, writing this week's column drew me back to 1957 when the Russians launched Sputnik into the sky. I bought my first telescope back then, a 4 1/4" Criterion Dynascope and with several friends formed the Northbrook Junior Astronomical Society. To this day I still own two telescopes, an 8" Celestron and a 13 1/2" Dobsonian.
Oh, wait, this is my marine biology column... not an astronomy one! However, as John Steinbeck wrote in The Log from the Sea of Cortez, "It is advisable to look from the tide pool to the stars and then back to the tide pool again." Of course John was putting into more palatable language the thoughts of his good friend, marine biologist Edward F. "Doc" Ricketts whose philosophical writings were full of gems (but torturous reading!).
Today's column focuses on another species which looks to the heavens... from the shallows of the ocean. I'm referring to the stargazers in the Uranoscopidae fish family. Although there are over 50 species in this group with distributions all over the world, I am very confident the one I filmed in the Philippines is the white margin stargazer (Uranoscopus sulphureus). Although it was initially buried in the sediment, our guide teased it out into the water column where I could see the white margins on the fins and the black spot on the first dorsal fin which are diagnostic characteristics. You can also see the smaller spots on the head and body. This species is known from the Indo-Pacific including the Red Sea, Indonesia, Australia, Fiji and Tonga in shallow water to depths of about 300 fsw.
Now if I were buried under the sand, I might experience some difficulty breathing... unless I had a SCUBA tank with me! The stargazer has adaptations to avoid intaking sediment when it pumps water past its gills. There are cirri (not to be confused with Siri) along the edge of the mouth to help filter the intake as well as a respiratory valve inside the lower jaw..
These fish are "anglers" and possess an extension from the lower lip often referred to as a lure to attract fish and invertebrates to the munching end of the stargazer. The upward-facing eyes and large mouth enhance its ability to capture food. Lying mostly buried in the sand, the unwary prey often doesn't notice this ambush and suction predator and becomes a victim... er, munchie. Menu items include fish and invertebrates such as crabs, octopus and squid.
I was surprised to discover in my research that many stargazers including this species possess several lines of defense in addition to burying themselves. I was unaware at the time that their pectoral fins have toxic spines and can inflict serious injury on humans and other predators. Yet in some parts of the world these fish are considered a delicacy and the poison in their spines is not toxic if cooked and eaten. In addition, they possess electric organs that can generate up to 50 volts to zap the unsuspecting with voltage depending on water temperature. The electric discharges may also be used to stun prey.
Apparently little is known about their reproduction. I did find a source that indicates they breed in spring and summer. No gory details thankfully. The female lays her eggs on the bottom. They later float to the surface and eventually hatch out as larvae. Once they are about one-half inch long they settle to the bottom and live out their lives there.
Two years after my trip to the Philippines, I was diving in the Egyptian Red Sea at Serib Kebir. As we entered the shallows, our group came across what I believed was another stargazer. I began filming it but our guide signalled to be cautious. This fish was almost completely buried like the stargazers with only its eyes and mouth visible. After we reached the beach, the guide told us it was a stonefish (probably Synanceia verrucosa). Good thing I didn't venture too close as they are thought to be the world's most venomous fish!
© 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: Whitemargin stargazer in "flight" and stargazers buried in the substrate with a stonefish (lower right) for comparison.
View attachment 486501
