Can crabs hear?

[Sly1461]

Hi all,

I'm relatively new to this hobby, I'm about a month in to my first saltwater tank and have just put in 6 red legged hermits and a couple of snails to start munching.

This may sound a daft question, but I installed a Reef Octopus BH100 shortly after putting the CUC in. The pump is loud and if you press your ear against the tank its a pretty awful noise that would drive me mad if I lived in it.

Will this effect the livestock in the tank? The hermits don't seem to move at all (they did at the start). They are all hidden in various cracks and dark places and stay put. Just wondering if this is normal behaviour.

On a side note this forum has been an amazing resource this last month! Thanks!

(25g tank, 25lb live rock, eheim prof 3)

 

[Dkuhlmann]

Welcome to Reef Central

I don't know how much crabs can hear but they most certainly can feel the vibrations.

As for Scarlet Hermits goes yes they move slower than a snails pace and IMO and IME they are the best hermits to buy. They do a great job of cleaning your sandbed and rocks and don't go on a killing spree of other hermits and snails just for sport.

As for your loud pump I would take it apart and pull out the impeller and see if it has something stuck to it like salt buildup. Also make sure you clean out the housing that it goes into with a toothbrush or something to make sure it's clean. There is a slime buildup that happens in there that will also reduce the speed of the pump impeller. These pumps are not usually noisy and its normally something that got sucked up in there creating the noise.

 

[Sly1461]

aaah thanks! Will take a look at it and let you know if I find anything, its pretty new so hopefully nothing has got caught up inside.

I had a thought that it could be the pump vibrating against the side of the tank going to see if moving it away helps decrease the noise a bit.

Cheers for the welcome!

 

[Dkuhlmann]

Ya, it could have a piece of anything in there and to get rid of vibration you can set it on a piece of rubber so it can have something to dampen the vibration. Which could be your whole problem

 

[Sly1461]

Rubber - great idea, I tried cotton wool this morning, what a muppet.

 

[MondoBongo]

i certainly hope not. otherwise they would be able to hear all the mean things i say about them.

in all seriousness though, they have a way of picking up sound waves, but it's not with ears like we have. they use their hairs all over their body to detect pressure changes in the surrounding water. since sound travels in waves through different mediums, they "hear" sounds with these hairs as the sound waves cause pressure differentials in the water.

very similar to how the human ear detects and interprets pressure waves in air.

http://museumvictoria.com.au/discoverycentre/infosheets/can-crabs-hear/

 

[chimmike]

don't go on a killing spree of other hermits and snails just for sport.

I LOL'd at this, picturing a hermit crab in a camouflage hat with reflective vest and visor "Be vewwy qwiet, i'm hunting hoimits!"