I love cases of symbiosis in nature, wherein two species work together for their mutual benefit (as opposed to parasitism, or the more benign commensalism, in which one species mooches to neither the benefit nor the detriment of its host). So when Ida sent me a couple of links (1 and 2) from the Web Ecoist about symbiosis, I had to share.

First we have a variety of marine crabs who have enlisted the aid of stinging anemones. The crabs benefit from having an added defense, and the sessile feeders benefit from being able to move through the water to filter feed with greater efficacy. My favorite is the boxing crab (upper photo), who wields his anemones like deadly pompoms.

(Images via: Flickr, AZAquaCulture, AquariaWorld, DeeperBlue and Diver)[Image]

























Next we have the egret. She doesn't discriminate; she'll enter into an alliance with any creature with a broad enough back and enough ticks and lice. She gains ready access to the tasty little parasites, while the ride gets deloused. The egret is a smart bird. I can't think of a safer place on the Savannah than on the back of a willing cape buffalo or elephant.

(Images via: DiegoPaccagnella and Angelfire)[Image]

























Ah, the plover and the crocodile. Crocodile opens wide for the plover because the plover likes to pick its teeth clean of rotting meat. Free dental care, free meal. But who was the first plover to try that? How was that arrangement arrived at? I want to shake that plover's hand. That took guts, even if it was on a dare.

UPDATE: Antagonist Jason has discovered that this photo is fake, and this instance of symbiosis with the crocodile is an ancient rumor, unsubstantiated by modern evidence.

(Images via: WarrenPhotographic, EnjoyFrance, AboutAustralia)[Image]

























Following that same line of thought, who was the first shrimp to venture in an eel's mouth? Perhaps we'll never know. Regardless, word has gotten around, and these shrimp congregate in droves at designated cleaning stations. Any creature with a mouth big enough is free to drop by for a clean, even if you're human.

(Images via: Nat.Geographic, AboutFish, DiveGallery, UWPhotos and ScienceBlogs)[Image]

























Last we have the infamous anglerfish, who has been swimming the depths of Ugly Overload for years now. Look at these photos and locate its symbiotic partner. Cant' find it? That's because it's in plain sight, and in the deep sea, it' the only thing in sight. It's the bioluminescent bacteria that reside within its angling lure. The fish get a lure, and the bacteria get a penthouse suite with a view.

(Images via: Wikipedia, EarthGuide, OceanExplorer and Nat.Geographic)[Image]

























But odd partnerships don't end there with the anglerfish:

to mate, a male angler bites a female, slowly dies and shrivels to a pair of gonads and is carried around by the female until she is ready to mate with his remains.There are all sorts of social commentaries embedded in that little tale of procreation and relationships between the sexes. I'll leave it to you to sort it out.

Thanks for the links, Ida.