HCA: Hermit Crab Association

I've now had the Repti Glo in the tank for two days and have noticed significant changes in the crabs.

They no longer go to the corner of the tank that gets sunny in the afternoon to stare at the sun. They've taken to staring at the light instead and can often be seen sitting under it. They also climb the fake plants and try to get very close to the light - but they do that with the heat lamp too, so it may just be for the heat.

They are more active - they were active before, but the amount of climbing they're doing is crazy.

They are more alert - their antennas are moving more than they use to.

They are much bolder. All are more out going and less prone to bolting away when we go near the tank. Spider was the shyest and spent all day, every day underground and would bolt if anyone came into the room. Since the light has been in there, he has taken to chilling out under the fake plants instead of being underground. He doesn't run off when we walk by the tank, and I was even able to remove the food dish while he was out without him being terrified. He just ambled off. For him, that's huge.

The 26W is very large - the glass section of the light is about twice the size of a normal compact fluorescent light bulb. So people might have trouble fitting it in some lamps.

It generates a lot of heat - perhaps comparable to a high wattage old style glass globe (the ones before the compact fluorescents came along.

The light it puts out is more yellow than white. I'm not totally keen on the way it makes the 'tat look, but I'm already getting use to it.

It is extremely bright. I went with the 26W to ensure I had enough light for my 120 gallon tank, but in a years time when it's time to change the bulb, I'll be getting two 13W ones and putting them at either end of the tank to balance it out a little (they'll still have shade though from the plants etc).

I'm expecting some of the crabs to molt soon, and I'm eager to see if there are any marked colour changes after their first molt with the light.

It's required some tweaking with increased heat, but I am so glad I bought it. The change in the crabs was well worth the money and they seem so much happier with it in there.

Update: The crabs have completely stopped going to the sunny corner each afternoon. Previously, the crab would all go one corner of the tank when it got sunny in the afternoon and they'd remain there until the curtain was closed or it got dark. New crabs and my two rescues were introduced to the tank in the afternoon and immediately bolted to the sunny corner (it was no warmer there than other parts of the tank so I know it wasn't for light).

That's completely stopped since the UVA/UVB light was put in. The crabs congregate near the light and have started coming out of their shells quite a long way while basking. There have even been fights over prime basking spots!!

When I turn it off at night, their activity levels drop, so I'm starting to have doubts about them being naturally predominantly nocturnal (by 'they' I mean C. variabilis "Aussies") as I've been told they are several times.

pics plz?!!???

I've had the same light installed in my 55 for a few weeks now and I'm having the exact opposite result! Few come out during the day, but as soon as it switches over to red night lighting (I have everything on a timer) it's time to PARTAY! My husband and I now switch off all our room lights when they are on red so that we can watch the crabs while we watch tv. I've definitely seen a huge increase in nighttime activity since installing the uvb light

My light is the 48" and is installed in a reptile hood with heat lamps over a mesh lid. There are many levels in my tank and also plenty of shade so the crabs can pick where they feel most comfy!

one thing to consider is heat verses rays. even when they need the rays of they wont subject them self to a heat that is to high. A shell that gets to hot in the heat holds heat. They also need night hours so its good to offer the night color bulbs at night red/ purple. there has been some controversy over the color red. Ive used both. In all cases its good to offer spots where they can hide from all light as well as cool spots in the tank. I like to use a thermometer probe to check the temp of different spots in the tank as well as in the substrate making sure no place is just way to hot as well as making sure there are enough cool down places.. It could be that the crabs coming out or hiding is because of the temperature of the area. One thing i have noticed with the full spectrum light is that as soon as you get them you can see colors in the crabs that you didnt even know were there, its easier to identify each crab. It helps them to properly digest the vitamins in the food and in my case i did see a color enhancement after molts with the crabs. One thing people often ask me is how do you get the colors of the crabs? I think that the lighting has alot to do with it, of course the foods do too. Id like to hear more as you find out more on your new light! This is very interesting! Suebee

thysmittenkitten, which species of crab do you have? I've often wondered if some species are more diurnal than others.

I've got PPs and Es they both seem to have about the same activity levels, which surprised me because I've always heard PPs are less active. When I started crabbing about a year and a half ago, I started with just PPs and they were fairly inactive. It was very interesting to me because as soon as I introduced Es to the tank (probably a month after initial set up) the PPs started keeping up with the Es! I adore Es and have had very good luck with them. I have more crabs together than some would agree with, but the Es seem to really thrive in large groups. Everyone wants to be on top of eachother and even travel the tank in groups, whereas the PPs are much more solitary, i rarely see them 'travelling' together. Has anyone else experienced this? Sorry that some of this is a bit off topic!!