Population density in the wild

[Coluber42]

Out of curiosity, what do wild populations of opae ula look like? What's the population density in their natural habitat? I'm not sure if you'd count them per square inch of surfaces (ground, rock surfaces, etc), or per unit volume of water. On YouTube you can find people's opae tanks where there are shrimp just completely swarming every available surface. Does anyone know of photos or video of opae in the wild?

[Varanus]

Judging by this video at least it seems they can live in pretty high densities: https://www.youtube.com/watch?v=2yIq3zwVR_k

[Stalker]

On YouTube you can find people's opae tanks where there are shrimp just completely swarming every available surface.

One of Mustafa's tanks

[Mustafa]

Not *quite*!

[Keystone]

There are several videos on YouTube that show them in in their native anchialine pools.I'll see if I can find any research papers on population density, but I would imagine aquariums densities can reach numbers never seen in the wild - constant stable environment & food plus no predators.

[Mustafa]

There are several videos on YouTube that show them in in their native anchialine pools.I'll see if I can find any research papers on population density, but I would imagine aquariums densities can reach numbers never seen in the wild - constant stable environment & food plus no predators.

Agreed!

[Stalker]

This may be of interest, even if its not about density in the wild.
http://scholarspace.manoa.hawaii.edu/bi ... =1#page=51

[Coluber42]

This may be of interest, even if its not about density in the wild.
http://scholarspace.manoa.hawaii.edu/bi ... =1#page=51

That was great, thanks! Interesting study.

[Stalker]

BTW remember supershrimp does NOT live in anchialine pools, they only visit them. Their true habitat is the porous lava belt circling each island, they go outside mostly to feed on certain algae and maybe take some sunlight for vitamins.

[Mustafa]

BTW remember supershrimp does NOT live in anchialine pools, they only visit them. Their true habitat is the porous lava belt circling each island, they go outside mostly to feed on certain algae and maybe take some sunlight for vitamins.

That's not quite right...they do live in the pools and their population seems to be greatest in those pools because that's where the food is abundant. They migrate to other pools using underground connections, but food there is very, very scarce underground and in caves so it's unlikely the population underground is larger than the population in the pools. Only when predators are around do the shrimp just "visit" the pools at night (when the predators are asleep) before retreating underground. Originally the pools didn't have predators like exotic fish, so the shrimp would hang out there all the time and in densities that would make the pool bottom look red supposedly according to local folklore.