Sea Urchins And Power Cables

Another discovery I've made in the process of breaking tanks down for a move...
 

 
This is one of those things I've known is a possibility for a long time with animals like sea urchins, but until now I've never actually seen it happen in a decade of keeping saltwater critters. I had a digital thermometer that went haywire recently and didn't think to check the in-tank part of it until a couple weeks later after replacing the battery didn't solve things. The part in the picture is just above the sensor and had been dragged down into the water without me noticing. If you look closely you can see it's been eaten all the way to exposing the wires with bits of wire hanging out. Nobody in the tank seemed stressed by having this thing with a battery in it having its wires frayed out into the water, but it's still not good that it was sitting in there like that. So, check our power cables regularly if you've got animals that like to chew!

Is that the wiring sticking out? Thats insane @.@

Wow
 
Thats quite amazing and quite worrying at the same time. This is down to sea urchins?
 
Well gotta say am glad am on the FW side then

techen said:

Is that the wiring sticking out? Thats insane @.@

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Yep - nice bits of copper wire that were right in the water for a while unfortunately. I'm sort of surprised I didn't see any invert casualties actually. Everything seems quite happy though so it must not have dissolved much.
 
 

Ch4rlie said:

Wow

 
Thats quite amazing and quite worrying at the same time. This is down to sea urchins?
 
Well gotta say am glad am on the FW side then

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Nothing else in the tank is inclined to that kind of behavior, but some urchins are chronic chewers on weird things even when they're well fed. Usually they just chew on rocks, but I've had many a seaweed clip devoured by urchins who didn't stop at the seaweed. I believe it was probably my Echinometra mathaei that was the culprit in this case. It is very defensive of its sleeping spot in the corner of the tank and anything that infringes on that area gets chewed to make room. It chose the spot when it was quite small, and there was a prior chewing incident where it carved away a large section of the hard plastic housing of a nearby powerhead to make space for itself. I didn't notice anything was wrong then either for a long time. The thermometer was a relatively recent addition and may have dangled and it too close for the urchin's liking.

I had this happen with my urchin only it was the cable leading to the wave maker attached to the mains! luckily I noticed before there was too much damage and solved it by covering all exposed wiring with pvc pipe the same type used in syphons.