Elysia chlorotica – Proving It May Actually Be Easy Being Green

This conniving little sea slug, Elysia chlorotica, may be a unique “hybrid” of plant and animal.

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a little background: skip to below the next set of asterisks for the “punch-line” concerning these sea slugs…

There is no lack of organisms forming unusual symbiotic relationships, especially those occurring between animal and plant.

The idea is generally that an animal, or more specifically a heterotrophic (can’t rely on sun energy, needs to consume other things for food and nutrients) organism might form a relationship with something autotrophic  (can easily produce its own energy via sunlight or chemical means).

The relationship works because both organisms tend to gain in some manner. The heterotrophic organism gains a more-readily available source of food produced by its symbiotic partner, the autotroph, which itself is likely gaining things like shelter and predator protection.

In the marine world, this is seen in corals polyps, which house tiny zooxanthellae, which are tiny little photosynthetic protozoa. Another fascinating example are the jellyfish like the ones found in Palau, that follow the sun everyday in order to fuel energy production in the symbiotic algae they host.

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E. chlorotica is different from these standard symbiotic relationship because they are not simply keeping the algal cells they consume in working order as usually happens in standard symbiotic relationships. It was previously known that the slugs would acquire photosynthetic organelles and genes from their algea food but it appears  they may be able to incorporate these “stolen goods” into internal chemical pathways to make their own chlorophyll, allowing them to photosynthesize their own food.  The results of the study supporting this find will be published in an upcoming issue of Symbiosis and may need to be scrutinized and further confirmed. But if the findings turn out to be true, there’s a whole lot of sneaky going around, folks.

Resources:

Read the original ScienceNews article

Check out Elysia chlorotica‘s wikipedia page

Visit the slick looking site- SymBio: A Look Into the Life of Solar-Powered Sea Slug

Ocean Acidification – The “Other” Inconvenient Truth

The National Resources Defense Council (NRDC) has just produced a film called “Acid Test: The Global Challenge of Ocean Acidification.”  The short film, which clocks in at about 21 minutes, features narration by Sigourney Weaver who also lent her voice to the recent Planet Earth series (although I happen to have the David Attenborough version, as I have a great deal of reverence for him and his narrative skills).

Most of us think of “carbon” as a buzzword intimately connected to the concept of global warming (the more apt word really is “climate change” as increased CO2 can, through complex and interesting ways, actually lead to cooling trends; but that’s a whole other topic…) but in terms of the ocean can lead to other unfortunate repercussions. The ocean has always been a major sink for CO2 and for quite some time has resisted strong ill effects due to its natural buffering system. A buffering system in chemistry terms allows a liquid (in this case, our “liquid” would be the entirety of the world’s oceans) to resist changes in pH when either acids or bases are added…. to a point. At some level, the system becomes “overwhelmed” and can no longer resist radical changes in pH.

The phenomenon’s name, “ocean acidification”, indicates the oceans are dropping in their pH, increasing in Hydrogen ions, and becoming more acidic in their composition. As more carbon pours into the sea, free carbonate ions (CO3) which are part of the oceans buffering system end up being tied up by the addition of extra CO2 (for the chemistry of this, check out the Center For Ocean Solutions’ Ocean Acidification page – the link is provided in resources at the end of this post). Unfortunately, carbonate is also a very necessary ingredient for the formation of the shells of a variety of organisms – corals, shellfish, pterapods, some types of plankton, etc. The lack of a supply of these carbonate ions actually can cause the shells of these creatures to dissolve, greatly increasing these species’ mortality.

The decalcification issue is also thought to be a stressor in what has been suggested as the return of the ocean to a primordial state, marked by a decrease in marine biodiversity and among other things, an increase in gelatinous marine organisms, most notably jellyfish. There are certainly a mix of reasons for the increase of jellies, but the decrease in shelled organisms helps release their gelatinous counterparts from competition for resources.

According to the Center for Ocean Solutions, other negative impacts include acidosis (a build-up of carbonic acid in marine organisms’ tissues leading to decreased immune response and other health consequences) and changes to the way sound travels underwater, resulting in the absorption of low frequency sounds which can inhibit communications and other uses of sound between sea creatures.

It’s yet another real and present danger we’re facing in today’s oceans.

Resources:

Chemtoons: Animations about how acids, bases, and buffers work

Center for Ocean Solutions: Decalcification

Center for Ocean Solutions: Ocean Acidification

Karl Grossman: The Jellyfish Revenge

NRDC – Ocean Acidification: The Other CO2 Problem

Giant Jellyfish and the Men Who Love Them

I’m re-posting a story originally featured on treehugger: A 10-Ton Japanese Fishing Trawler Sunk By Giant Jellyfish

 

Here’s the text from the post:

You could say it was the jellyfish, or you could say it was the overzealous fishermen on board. While trying to haul in a catch of several dozen giant Nomura’s jellyfish – one of the largest in the world – a Japanese fishing trawler tipped right over.

According to the Telegraph, “The crew of the fishing boat was thrown into the sea when the vessel capsized, but the three men were rescued by another trawler, according to the Mainichi newspaper. The local Coast Guard office reported that the weather was clear and the sea was calm at the time of the accident.”

It’s no wonder only a few dozen could capsize a boat. Each jellyfish can weigh as much as 450 pounds. This year has seen a big spike in the numbers of these giant jellies, with a similar population boom not occurring since 2005, when the large numbers of jellyfish and their stinging tentacles ruined fishing nets and made catches of fish inedible. Both ideal weather conditions and a smaller number of predators, such as sea turtles and certain fish species have helped the jelly populations grow this year.

Check out the size of these things next to divers:

While they don’t make that great of a meal, fishermen might as well catch what is plentiful and edible – and these certainly fit that bill. In the effort to make something tasty out of the abundant creatures, even high school students are putting their heads into it, making caramel candies out of them…which they’d like to feed to astronauts. Giant jellies invading Japanese water, capsizing boats, and becoming food for space travelers…sound like a teen sci fi book to anyone else?

Even though it might be possible to make something yummy from them, catching them isn’t exactly fun. In 2007, there was a grand total of about 15,500 reports of fishing equipment damaged by the Nomura’s jellyfish. Add a 10-ton trawler to the list of ruined equipment to this year’s reports.