symbiotic relationship?

[BiGGj711]

what exactly is a symbiotic relationship? i have heard certain pairs of tankmates will form this...for example, the pistol shrimp and the yellow watchman. why do they form this? from the little info i have heard on this relationship, it sounds interesting to watch...any other combos of creatures that form this also?

[movingshadow]

there are many... if you do a search here and on google you'll get TONS of information. To go into the symbiotic relationships of aquarium animals (like clownfish/anemone, pistol-shrimp/gobies, etc...) would be waaaaay to much for one thread, though these relationships are usually based on protection from predators/pests... hope that helps

[BiGGj711]

thanks, i'm reading search results right now, but as with all searches, i'm sifting through all the BS....anyways, i'm thinkin this could be an interesting thread - post your OWN experiences with symbiotic relationships in your own tank(s). in my opinion, what books and references say happens in nature isn't always what happens in front of you...i've kept a freshwater tank for years, but i'm generally new to saltwater, so this is a whole new amazing world for me. just bought a nanocube yesterday and will post specs after its up and running (can't wait to be part of the nano-reefers)

[movingshadow]

well then, welcome to the nano-world and to nano-reef.com!!

 

I've got a clarkii clownfish hosting in a red/pink entacmaea anoemone... love the clownfish, not the nemo

[Fant]

Symbiosis is generally defined as two unlike organisms living togeather, usually it consists of a larger animal the 'host' which provides the environment (its body, burrow, nest, etc) and the smaller animal the symbiont. There are several sub categories of symbiosis which include parasitism, mutualism, commensalism.

 

parasitism is pretty straight forward and most are familiar with this. In this type the host usually does not benefit and in best case scenario is just not harmed, worst case scenario the host is harmed or even killed. Such relationship can be found in aquaria when you see ick infestations on fish, or parasitic isopods attacking fish.

 

Mutualism is generally defined as a scenario that both the host and the symbiont benefit from the relationship. This can be seen in the relationship of anemone/clownfish. Many cnidarians and their algae symbionts zooxanthellae. Cleaner wrasses and other large reef fish. In some instances the relationship is considered obligate, such as clownfish and anemone. The clownfish is an obligate symbiont to its host anemone. You will never see a clownfish in the wild in the absence of an anemone.(This does not hold true for aquaria, clowns can be maintained without anemones, anemones are to be considered delicate and keeping them should not be attempted by the beginning hobbyist).

 

In other cases the relationship is less critical to the survival of both parties involved and is called fulcrative. Cleaner shrimp are fulcrative mutualists of many reef fish, they remove parasites from other fish and obtain nutrition while the fish benefits from having parasites and dead scales removed.

 

the third type of symbiosis is called commensalism, this category is for sorta grey area associations, where significant harm/benefit is not obvious, this is usually used to describe relationships were the symbiont benefits and the host is seemingly unaffected. This category would probably include pistol shrimp/gobies. Gobies are also known to share the burrow of priapulans, cucumbers, and other large burrowing invertebrates. The pistol shrimp/goby relationship is actually considered a subcategory of commensalism an is called inquilism where one organism shares the burrow of another, in this case the goby is sharing the burrow of the shrimp and recieves protection. Its a common belief that the pistol shrimp is blind and uses the goby as a watchman, but recent studies are compiling more and more evidence that pistol shrimp actually see quite well.

 

There is a final special type of commensalism called phoresis, this is where the two organisms travel togeather but lack any physiological/biochemical dependance of either organism. one is usually larger then the other and is simply carried about by its larger companion. There are certain type of athecate hydrozoan colony that forms a shell like corallum that is favored by a species of hermit crabs. The hermit crab carries the living hydrozoan colony instead of a classical mollusc shell. The hermit does gain some protection as well but its close enough to phoresis that i could think of.

[movingshadow]

see, I just didn't want to type all that good post Fant!