Biodiversity

Paul B

Premium Member
Biodiversity. Just rambling, I am facinated by this. I also think it is a cool word. But for us aquarists it is restricted to marine animals, some good (for our tanks) and some bad (for our tanks). All animals are good for something, at least they think so. Even paracites have a purpose and a niche, although I can't think of one at the moment.
Looking at an aquarium we first notice the fish, then the corals and rocks and as we get closer and more interested, we can barely pick up movement in darker areas. Under and between rocks, crawling or slithering through the substrait. These are the things that facinate me. Yes I have some fish and corals but they are common. Everyone knows all about them and we all have or had them or at least seen them. But the creatures from the darker zones, thats where the real action is.
In my reef there are maybe 18 fish, but I would imagine that for each fish there are a hundred brittle stars, fifty bristle worms, a thousand amphipods and possably a million copepods. I never counted so don't hold me to those numbers.
But we rarely look at a tank and say "wow what a cool amphipod that is". Well I do, but I am a little strange.
Take a brittle star for instance, very cool animal. They hang out all day under a rock with one or two arms sticking out. I am not sure why they are hiding because almost nothing eats them. I guess it is because even though the fish don't eat them, they do pick them up, chew on them, then spit them out. Maybe that is the reason they hide. Good reason, anyway, how do they even know they are hiding? They have no eyes, no brain, and no ears. They don't even have a lateral line like all true fish have to help them get around. Instead of those sensors they have others more suited to a bottom dwelling animal. Even without eyes they can sense light. We can also if we just close our eyes we can tell light from dark. But what really facinates me about these and animals living in similar habitats is the fact that even without a brain, they are so much better at some things than we are. Maybe not basketball or pole vaulting but their ability to find food. We humans can smell certain foods from a few feet away but if you put blindfolds on us and put us in a room with 4 or 5 fans blowing the air all over the place I doubt we would know where the food was.
Snails and crabs can, as can brittle stars and bristle worms. Sharks can do that with blood and they can sense electrical signals but they have a brain.
I have a small tank with local snails, worms, crabs and shrimp. There is a small powerhead in there also. If I throw in a pellet, in about 5 seconds the seemingly sleeping snails all turn in the direction of the pellet and "race" to the exact place, trying to beat out the crabs. I don't know how much a dry pellet smells but I don't think it is all that much but I really don't have any idea how these "lower" animals can know the direction to go. Especially with the water swirling about, but they never falter, they know exactly what direction to go.
Amphipods are another cool animal. Most tanks don't have these as I collect them in the sea, they are different from copepods that are in all tanks as they are many times larger. We tend to call anything tiny a copepod but they are not all the same. Many of them are the young of crustaceans and most of them will die in a tank long before they get much larger than a real copepod. They haven't yet mastered the art of growing up away from the sea which is the reason we don't see baby hermit crabs or coral banded shrimp all over our tanks. Hermit crabs and shrimp spawn all the time as do all crabs and shrimp but the babies all die in a few days.
It must be frightening to be one of these animals, Oh wait, they have no brain so I guess they can't be frightened, good thing too because as a brittle star lays around waiting for a meal there are also, in the same hole bristle worms. They crawl all over each other but they don't seem to mind.
I guess these creatures make better neighbors than some of us. :wavehand:
 
Neat little post. I still find myself pulling out a flashlight and magnifying glass every night to see whats going on in my tank after lights out. I even found a few small worms living in my skimmer last night. I also still enjoy dropping a piece of silverside in the tank and watching the nassarius snails rise from the sand almost instantly and heading off to find it. I think these tiny life forms are one of the most interesting parts of this hobby.
 
So do I. There are tentacles coming out of every nook in my rocks. And if I touch the rock with a probe, amphipods run out. I love this stuff.
IMG_1302.jpg
 
@ Paul B: Nice post. And I agree with you. For some reason I spend the most time in the "Other invertebrates"- and "Hitchhikers"- sections :-)

The little critters that come in on the live rocks made me start my SW tank.

Actually, if I had the space and money, I would probably keep getting new tanks on a regular basis just so I could get more live rock and hitchhikers :-/
 
if I had the space and money, I would probably keep getting new tanks on a regular basis just so I could get more live rock and hitchhikers :-/

Aerie, I am lucky that I live by the sea and have a boat so I am able top go out collecting rock and the associated fauna all the time. I started my tank with NSW and rocks I collected so many of the organisms in my tank I am not sure if they are tropical or New Yorkers.

My wife always asks why am I sitting so close to the tank!!!! lol
When I hear my wife coming down the stairs to where the tank is, I grunt and pick up a dumbell.
 
I hear the occasional "staring at rocks again??" comment every now and then, too... apparently not everyone is able to find beauty in a quarter-inch-long, alien-looking creature with way too many legs...
 
Nice post...and why I'm no big fan of dead/dry rock....

...then again of course it seems the status quo seems to be shooting for that ultra clean "minimalist" look with crystal white sand, gaudy SPS corals and zero pest <apparently>...

and putting it bluntly, you won't get TOTM for a tank being "interesting" with hordes of lil biodiverse interesting lil critters scurrying about....naw; those lil bugs don't make for gaudy cartoonish pictures ("orange stars" AND "green clovers")
 
Doctorgori, I never got TOTM, I am now going for amphipod of the week
"What is that thing?"
IMG_1301.jpg
 
I´m all for "Amphipod of the week"! :-)

I don´t really care about SPS because - for me - a SW aquarium should have things with long, waving tentacles... which is why I keep and target-feed my largest Aiptasia (I nuke the rest because I don´t want an invasion)... Now if I wanted to spend a massive amount of time, effort, and money, I´d go for an Azoo tank... the colours of the creatures and the pics of those tanks always make me drool very heavily ;-)
 
Thank you so much for this post. So many people in this hobby get caught up in fuzzy sticks or high tech gadgets. To each his/her own.

My background is in invertebrate paleontology. I LOVE the non-coral inverts that we typically find in our tanks. :)
 
It is amazing to see the expresion on a persons face when they FINALY focus on a rock long enough to be able to see the itty bitty doozers (err, pods) running around. Once they seem them, then they notice them everywhere.
 
Last edited:
Thank you so much for this post. So many people in this hobby get caught up in fuzzy sticks or high tech gadgets. To each his/her own.

My background is in invertebrate paleontology. I LOVE the non-coral inverts that we typically find in our tanks. :)

:thumbsup: :thumbsup:

....sums it up perfectly....
...and don't you kinda hate it when people define/pigeon hole the hobby for you?

...matter of fact who says our goal HAS TO BE ultra ultra LPS and neon green SPS's over fake AZZ "arches & islands" with crystal sand and $500 powerheads....

...yeah I'm gonna end up doing a mixed reef, but an albeit "too clean" one from an intrest standpoint
 
I get it bad from my family. I use a pair of binoculars that were made to watch butterflies so the focus range is very close. Really great for scanning all the nooks and crannies in my tank. But my background is a "mud biologist", so I am used to seeing the world thru a microscope.
 
I don't know how many of these local mud snails and grass shrimp are in my reef but I dropped two pellets in this spot and with in 5 minutes there are 8 mud snails and 3 grass shrimp here fighting for lunch.
The tank is 6' long so they came from long distances to get here.

IMG_1309.jpg
 
Totally agree sometimes I get real close to my tank and just stare. Then my wife will ask "whats wrong?" For fear of red bugs or something of the sort and I assure her everyrthing is fine and I am just noticing the wierd bugs or my favorite thing is to turn over a rock that has been in some place for a long time and find all the sponge growth. I have some really cool bright pink sponge that grows in my tank only problem is it grows where I cant see it unless I turn over my rocks. Also I use a red flashlight to look at night and find more bugs.
 
My amphipods are so at home (and numerous in number) that they are out and about all the time on every surface. Feeding time you see one amphipod grab a pellet half its size and start running off to whatever hole it likes to eat at and then a bunch try and steal it from him. The smallest snails in my tank are much more communal, they form a cluseter 2-5 snails deep even for the smallest scraps. Brittle stars are hiding all over, every now and again you see one run across the gravel bottom only to duck back down at its apparent destination. Bristle worms (the good kind) inhabit a ton of holes too, which is funny, as i only ever added one on purpose (most of my rock was dry), and since then i have never seen 2 ends of 1 worm at the same time. There is one in the tank that is so long and fat... i have seen it stretch out to a good 6" or so and its at least 1/4" wide. Even then it was probably only half out of its hole. Basically every shady surface has tube worms or their tubes built up if there is any sort of flow to get food with. Their reaction time is simply amazing, though i am not sure what they react to half the time. Zebra legged hermit crabs one up each other by going for shells you would never imagine they could carry, and then proceed to climb a vertical wall and hang from an overhang to get onto a higher plane. And that is only daylight time.

I have some fish too. And a couple of frags. =D

I have actually wondered many a time on how many living creatures (i wouldn't count coral polyps individually or bacteria at all, but am unsure how to better define it) are in the tank. There is 6 fish, 1 shrimp, 3 big snails, 3 other snail species i have no hope of counting, 1 species of crabs, tube worms, amphipods (don't know about copepods) and bristle worms... i would say easily over 100 (without counting amphipods), most likely over 500, maybe even over 1000. And i don't consider my tank big.
 
Gorgok, thats my kind of tank.

Yesterday I was looking at this guy who was resting in a hole. Suddenly I noticed there was something in there with him. I took my flashlight (that I keep next to the tank) and peered in. It was a huge bristle worm wrapped around the bleeny. At first I thought the fish was dying and the worm was eating him. But on closer inspection the worm was only hanging out with the fish and needed a place to rest it's tail which was almost completely wrapped around the fish.
I put in some black worms and the bleeny came out to grab some then hurried back to the hole where the bristl worm again rested his tail over the fish.
This fish has been with me a few years so I guess he knows where the safe places to rest are and he is in no danger.


 
Back
Top