skalja
in
wtf_nature
in ur black sea, crashing ur economy
So I know I said I was going to post about Mantis Shrimp, which I will because they are the BEST INVERTEBRATES EVER, but after a conversation with a deeply misinformed person who refused to listen to me ("Releasing extra pet store crickets into the wild is a bad idea; non-native organisms can spread disease, create competition, and interbreed with the natives, and cause all kinds of ecological havoc" ; "LOL, they're just crickets, she can release them if she wants" ; "... *tears out hair*"), I feel like talking about warty comb jellies, also known as Atlantic comb jellies, scientific name Mnemiopsis leidyi.
(Thanks, Dr. Matt Gilligan! You take pretty pictures.)
The comb jelly phylum, or Ctenophores, are not jellyfish (Cnidaria) - most obviously they lack the stinging cell cnidocytes that give cnidaria their name. Actually, these days scientists think that ctenophores are more closely related to the Bilateria, aka bilaterally symetric animals (that's us, dudes!).
More fun facts about ctenophores:
- they are all oceanic, a kind of large plankton
- they are the largest animals to propel themselves using cilia
- instead of cnidocytes, they use colloblasts - basically, "lasso cells" filled with a gluey substance to stick to prey
- read more about ctenophores in general at Wikipedia
And now, back to our friend the Warty Comb Jelly. (Who, by the way, is possibly bioluminescent and all strobey-like. [3 video links]) As you might guess from its alternate name, it's native to Atlantic coastal waters. But back in the 1980s it was accidentally introduced into the Black Sea through ships' ballast water.
"Hey, rabican, what's ballast water?" This website posts a great little breakdown, but basically, ships without cargo take on water to provide stability. Historically, they didn't really think about all the little beasties they were also bringing on board - and dumping off at the other end. The situation with M. leidyi is pretty much a case study of why this is very, very bad.
Y'see, the Warty Comb jelly feeds on the eggs and larvae of fish ... like anchovy, a major commercial stock in the area. No eggs, no larvae, no fish ... no money. WHUPS, THERE GOES THE ECONOMY.
1982 - first record of M. leidyi in the Black Sea.
1989 - peak of Black Sea population (400 specimems per cubic meter); eventually this drops due to depletion of foodstocks.
1997 - Beroe ovata, another comb jelly, is either accidentally or deliberately introduced into the Black Sea. As it happens, B. ovata preys on M. leidyi. Oh, that's helpful! Some amount of balance is restored, although both jellies remain in the ecosystem.
1999 - However, M. leidyi reaches the Caspian sea and decimates 75% of the zooplankton. Bye bye food chain!
2006 - Spotted in the North Sea, the Baltic, and apparently spread throughout the Mediterranean. It's basically not going anywhere at this point because it can find deep, warm water in which to overwinter. Crap on a stick.
Quoth Wikipedia, the anchovy market has "stablized, albeit at a much lower level." And that's how a 5-inch long organism crashed the Black Sea economy.
What have we learned today?
1) Don't release non-native organisms into the wild. It's bad.
2) There are waaaay more YouTube videos of Ctenophora then you'd have thought. Seriously!
(Thanks, Dr. Matt Gilligan! You take pretty pictures.)
The comb jelly phylum, or Ctenophores, are not jellyfish (Cnidaria) - most obviously they lack the stinging cell cnidocytes that give cnidaria their name. Actually, these days scientists think that ctenophores are more closely related to the Bilateria, aka bilaterally symetric animals (that's us, dudes!).
More fun facts about ctenophores:
- they are all oceanic, a kind of large plankton
- they are the largest animals to propel themselves using cilia
- instead of cnidocytes, they use colloblasts - basically, "lasso cells" filled with a gluey substance to stick to prey
- read more about ctenophores in general at Wikipedia
And now, back to our friend the Warty Comb Jelly. (Who, by the way, is possibly bioluminescent and all strobey-like. [3 video links]) As you might guess from its alternate name, it's native to Atlantic coastal waters. But back in the 1980s it was accidentally introduced into the Black Sea through ships' ballast water.
"Hey, rabican, what's ballast water?" This website posts a great little breakdown, but basically, ships without cargo take on water to provide stability. Historically, they didn't really think about all the little beasties they were also bringing on board - and dumping off at the other end. The situation with M. leidyi is pretty much a case study of why this is very, very bad.
Y'see, the Warty Comb jelly feeds on the eggs and larvae of fish ... like anchovy, a major commercial stock in the area. No eggs, no larvae, no fish ... no money. WHUPS, THERE GOES THE ECONOMY.
1982 - first record of M. leidyi in the Black Sea.
1989 - peak of Black Sea population (400 specimems per cubic meter); eventually this drops due to depletion of foodstocks.
1997 - Beroe ovata, another comb jelly, is either accidentally or deliberately introduced into the Black Sea. As it happens, B. ovata preys on M. leidyi. Oh, that's helpful! Some amount of balance is restored, although both jellies remain in the ecosystem.
1999 - However, M. leidyi reaches the Caspian sea and decimates 75% of the zooplankton. Bye bye food chain!
2006 - Spotted in the North Sea, the Baltic, and apparently spread throughout the Mediterranean. It's basically not going anywhere at this point because it can find deep, warm water in which to overwinter. Crap on a stick.
Quoth Wikipedia, the anchovy market has "stablized, albeit at a much lower level." And that's how a 5-inch long organism crashed the Black Sea economy.
What have we learned today?
1) Don't release non-native organisms into the wild. It's bad.
2) There are waaaay more YouTube videos of Ctenophora then you'd have thought. Seriously!