DIVE DRY WITH DR. BILL #713: THE BARBED WIRE "JELLYFISH"
Years ago I encountered a "critter" that looked like a bleached frayed rope in the water. I wasn't entirely sure what it was at the time and slowly approached it with my video camera running. Suddenly there was an unexpected current that wrapped the frayed rope around my face. In addition to cries of pain I think I uttered a few four letter words (which I carefully edited out of the soundtrack when I got home).
I had observed what appeared to be tentacles that created the frayed appearance and since they were obviously capable of stinging, I was pretty sure the "critter" belonged to the phylum Cnidaria (formerly known as the Coelenterata). This group is known for its stinging cells. To narrow down the ID, I looked in my field guides and identified it most likely as Apolemia uvaria. According to Wikipedia, this "critter" is known by several common names including the string or barbed wire "jellyfish" (which it is not) and the "long stringy stingy thingy."
Although related to jellyfish and other stingers (but not honeybees or wasps), it is actually a form of siphonophore more closely related to the Portuguese man-of-war. I remember those from my days as a budding biologist walking the beaches of northern Florida. My Mom had more vivid memories of them since she actually got stung by one.
There is still debate as to whether siphonophores are a single organism with specialized structures or a colony of individuals known as zoids. These zooids are connected physiologically by a common digestive and circulatory system, and would not survive if swimming solo suggesting it is a single organism. The central "string" has groups of pink and white tentacles along it which function either for feeding or reproduction. Intact colonies have a gas-filled float bulb (pneumatophore) at the forward or apical end and a set of swimming bells (nectophores) for propulsion.
Although the colony is capable of movement, these pelagic or open water "critters" largely drift with the currents. Wikipedia states that these plankton predators act like drift nets extending their tentacles to capture breakfast, lunch, dinner and any snacks in between using their powerful sting.
Although some sources state that their sting is strong enough to kill large fish (but not Dr. Bill), I found this surprising. I have filmed kelp bass and garibaldi sucking in small strands of Apolemia and seemingly enjoying it. I guess they just enjoy a spicy treat occasionally. I prefer my Thai green curry or the Szechuan beef at Mr. Nings.
During my research on this species, sources reported wildly different maximum lengths of Apolemia colonies. Wikipedia stated a mere three meters (about 10 ft) while others listed 50 ft or even 100 ft (30 m). The 30 m (100 ft) length was substantiated by the Monterey Bay Aquarium Research Institute (MBARI). I have observed lengths in excess of 25 ft, but also many fragments of colonies in the inches to foot range.
MBARI referred to Apolemia as "the ocean’s way of celebrating Christmas all year long." I failed to see their logic in doing so. It had something to do with how this siphonophore begins with an egg developing into the central stem. Through cloning the propulsion end is created as well as the clones responsible for gathering food. I think the researchers there may have celebrated with a bit too much eggnog! Another source repeated this claim and referred to Apolemia as "gelatinous Christmas tinsel."
So, swimmers, divers and anglers... heed this warning. If you happen upon a gelatinous frayed rope in the water, look but don't touch.
© 2016 Dr. Bill Bushing. For the entire archived set of over 700 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Images of Apolemia and garibaldi chowing down on one.
Years ago I encountered a "critter" that looked like a bleached frayed rope in the water. I wasn't entirely sure what it was at the time and slowly approached it with my video camera running. Suddenly there was an unexpected current that wrapped the frayed rope around my face. In addition to cries of pain I think I uttered a few four letter words (which I carefully edited out of the soundtrack when I got home).
I had observed what appeared to be tentacles that created the frayed appearance and since they were obviously capable of stinging, I was pretty sure the "critter" belonged to the phylum Cnidaria (formerly known as the Coelenterata). This group is known for its stinging cells. To narrow down the ID, I looked in my field guides and identified it most likely as Apolemia uvaria. According to Wikipedia, this "critter" is known by several common names including the string or barbed wire "jellyfish" (which it is not) and the "long stringy stingy thingy."
Although related to jellyfish and other stingers (but not honeybees or wasps), it is actually a form of siphonophore more closely related to the Portuguese man-of-war. I remember those from my days as a budding biologist walking the beaches of northern Florida. My Mom had more vivid memories of them since she actually got stung by one.
There is still debate as to whether siphonophores are a single organism with specialized structures or a colony of individuals known as zoids. These zooids are connected physiologically by a common digestive and circulatory system, and would not survive if swimming solo suggesting it is a single organism. The central "string" has groups of pink and white tentacles along it which function either for feeding or reproduction. Intact colonies have a gas-filled float bulb (pneumatophore) at the forward or apical end and a set of swimming bells (nectophores) for propulsion.
Although the colony is capable of movement, these pelagic or open water "critters" largely drift with the currents. Wikipedia states that these plankton predators act like drift nets extending their tentacles to capture breakfast, lunch, dinner and any snacks in between using their powerful sting.
Although some sources state that their sting is strong enough to kill large fish (but not Dr. Bill), I found this surprising. I have filmed kelp bass and garibaldi sucking in small strands of Apolemia and seemingly enjoying it. I guess they just enjoy a spicy treat occasionally. I prefer my Thai green curry or the Szechuan beef at Mr. Nings.
During my research on this species, sources reported wildly different maximum lengths of Apolemia colonies. Wikipedia stated a mere three meters (about 10 ft) while others listed 50 ft or even 100 ft (30 m). The 30 m (100 ft) length was substantiated by the Monterey Bay Aquarium Research Institute (MBARI). I have observed lengths in excess of 25 ft, but also many fragments of colonies in the inches to foot range.
MBARI referred to Apolemia as "the ocean’s way of celebrating Christmas all year long." I failed to see their logic in doing so. It had something to do with how this siphonophore begins with an egg developing into the central stem. Through cloning the propulsion end is created as well as the clones responsible for gathering food. I think the researchers there may have celebrated with a bit too much eggnog! Another source repeated this claim and referred to Apolemia as "gelatinous Christmas tinsel."
So, swimmers, divers and anglers... heed this warning. If you happen upon a gelatinous frayed rope in the water, look but don't touch.
© 2016 Dr. Bill Bushing. For the entire archived set of over 700 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Images of Apolemia and garibaldi chowing down on one.
