DIVE DRY WITH DR. BILL #854: PREDATOR
No, I'm not talking about Arnold's film from 1987. I'm not even talking about lions, tigers, crocodiles or sharks (definitely not sharks). Like most things in life, predator is a relative term. When you mention the word, most people who aren't cinema fanatics will conjure up images of something big that could chow down on an unwary Homo sapiens. However, in "The Mutual Eating Society" (as I refer to the ecological world), predators can be pretty tiny themselves.
Let's scale down an order of magnitude and consider the relatively small blacksmith or kelp surfperch. Neither one would give our species a reasonable filet. However, those bull kelp bass that come out at night and the morays that often accompany them find them a filling meal. Their stomachs aren't quite as big as those in our species.
We could go even smaller and consider the decimation of mosquitoes (hurray!) caused by those flying Odonates. Yes, I'm talking about dragonflies. And mammals like bats get into the act of terrorizing the poor defenseless (yeah, right) biting insects. There's a lot of munching at this order of magnitude in the world. Of course I'm not including the much larger fossil species in the genus Meganeuropsis which had a 30" wingspan. A bit of trivia.. it was discovered and named by my entomology professor at Harvard, Dr. Frank Carpenter. I spent many weeks dissecting cockroaches in his lab. Maybe that's why I prefer marine biology!
Going back to the water world, we can look to the nudibranchs as another example. Most divers marvel at the incredible diversity and beauty of these shell-less snails. But to a sponge or a hydroid or a bryozoan (and sometimes even a "fellow" nudibranch), they can be looked upon as very vicious predators. I've spent many dives watching one tear a sponge apart or decimating an entire colony of hydroids. They are no threat to us, but to their prey they are quite scary (not to be anthropocentric).
Recently, Erik Goossens my Belgian dive buddy in Anilao, the Philippines, posted an excellent example of terror at the near-microscopic level of the ecosystem. He continues to travel to the Philippines for more great diving. I just wish I could join him and some of my friends from the PI back there. I was able to get in 60 dives, some longer than two hours, in just over two weeks. I was a bit waterlogged when I got back to the States... and I'm still editing the video footage from that trip seven years later!
Oops, I digressed... not an uncommon thing at my age! Back to the image Erik posted on Facebook recently. It showed a tiny colony of hydroids with a "gargantuan" monster about to munch on them. The monster was a caprellid amphipod so small most divers can barely see them. I've seen them doing the same thing with hydroids right here in our dive park. And then there was the day that lifeguard Paul (aka Rambo) came back from cleaning boat hulls and had hundreds (if not thousands) of the caprellids, otherwise known as skeleton shrimp, covering his wetsuit. Don't worry... Paul survived the encounter. The amphipods not so much.
So predation occurs at all scales in both the water and terrestrial world on our planet. While you may fear getting munched on by a great white shark (a largely irrational fear in my mind), neither the tiny caprellids or the even smaller hydroids sense any fear if one swims by. Likewise, we aqua-persons have nothing much to be scared of when confronting a vicious nudibranch predator. It's all relative, my friend. Of course we humans can fall victim to a microscopic virus, but the current coronavirus scare is largely overblown in my opinion.
© 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: Caprellid amphipod standing on its "hind quarters" as it contemplates chowing down on a tiny colony of hydroids.
No, I'm not talking about Arnold's film from 1987. I'm not even talking about lions, tigers, crocodiles or sharks (definitely not sharks). Like most things in life, predator is a relative term. When you mention the word, most people who aren't cinema fanatics will conjure up images of something big that could chow down on an unwary Homo sapiens. However, in "The Mutual Eating Society" (as I refer to the ecological world), predators can be pretty tiny themselves.
Let's scale down an order of magnitude and consider the relatively small blacksmith or kelp surfperch. Neither one would give our species a reasonable filet. However, those bull kelp bass that come out at night and the morays that often accompany them find them a filling meal. Their stomachs aren't quite as big as those in our species.
We could go even smaller and consider the decimation of mosquitoes (hurray!) caused by those flying Odonates. Yes, I'm talking about dragonflies. And mammals like bats get into the act of terrorizing the poor defenseless (yeah, right) biting insects. There's a lot of munching at this order of magnitude in the world. Of course I'm not including the much larger fossil species in the genus Meganeuropsis which had a 30" wingspan. A bit of trivia.. it was discovered and named by my entomology professor at Harvard, Dr. Frank Carpenter. I spent many weeks dissecting cockroaches in his lab. Maybe that's why I prefer marine biology!
Going back to the water world, we can look to the nudibranchs as another example. Most divers marvel at the incredible diversity and beauty of these shell-less snails. But to a sponge or a hydroid or a bryozoan (and sometimes even a "fellow" nudibranch), they can be looked upon as very vicious predators. I've spent many dives watching one tear a sponge apart or decimating an entire colony of hydroids. They are no threat to us, but to their prey they are quite scary (not to be anthropocentric).
Recently, Erik Goossens my Belgian dive buddy in Anilao, the Philippines, posted an excellent example of terror at the near-microscopic level of the ecosystem. He continues to travel to the Philippines for more great diving. I just wish I could join him and some of my friends from the PI back there. I was able to get in 60 dives, some longer than two hours, in just over two weeks. I was a bit waterlogged when I got back to the States... and I'm still editing the video footage from that trip seven years later!
Oops, I digressed... not an uncommon thing at my age! Back to the image Erik posted on Facebook recently. It showed a tiny colony of hydroids with a "gargantuan" monster about to munch on them. The monster was a caprellid amphipod so small most divers can barely see them. I've seen them doing the same thing with hydroids right here in our dive park. And then there was the day that lifeguard Paul (aka Rambo) came back from cleaning boat hulls and had hundreds (if not thousands) of the caprellids, otherwise known as skeleton shrimp, covering his wetsuit. Don't worry... Paul survived the encounter. The amphipods not so much.
So predation occurs at all scales in both the water and terrestrial world on our planet. While you may fear getting munched on by a great white shark (a largely irrational fear in my mind), neither the tiny caprellids or the even smaller hydroids sense any fear if one swims by. Likewise, we aqua-persons have nothing much to be scared of when confronting a vicious nudibranch predator. It's all relative, my friend. Of course we humans can fall victim to a microscopic virus, but the current coronavirus scare is largely overblown in my opinion.
© 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: Caprellid amphipod standing on its "hind quarters" as it contemplates chowing down on a tiny colony of hydroids.
