HCA: Hermit Crab Association

Reading Jess's post on moon glo & reptile bulbs has made me wonder how important day & night cycles are? What are the benefits or adverse effects on crabs that do or do not have 12 hrs of light & 12 hrs of darkness.My older crabs are less nocturnal & now that I think about it, do not get a regular day & night cycle. Some days, they only get a few hrs of darkness. Some days they might only get a few hrs of light. It all depends on my work scedule & my bedtime since the tanks are in my bedroom.Anyone know why they need a day & night cycle & how important it is?

Day night cycles are important for all living things (That live above ground).The daylight coming through a window in the room is enough for basic day-night brightness changes. However, hermit crabs seem to benefit from full-spectrum sunlight, which is blocked by the window glass (UVB, which requires day lighting in the tank). I don't recommend leaving your crabs in the dark 24/7.Beyond that, if you have a large enough crabarium, daily fluctuations to simulate a natural environment are best (UV-light during the day, moonlight at night, increase in temp during the day, changes in humidity levels, changing food sources, etc).

i never really put a lot of thought into UVA/UVB rays before. for the sake of convienance (and sanity) i simply purchased nitetime lights for the tank and keep them on 24/7 for heating. the tank gets natural light during the day so i figured this was sufficient for day/night cycles. is it of serious concern to get the UVA/UVB rays?

I don't think it's a serious concern. It's just one of those things you put on your list for future 'tat upgrades. Every 6 months or so I try to do something new for my crabitat.For instance, you might have a crab wish-list that includes a bigger tank, bubbler pools, some climbing nets, etc. Nobodies ever going to achieve "perfect tank", so we just take things one step at a time, an do what we think is best for our hermies, and is also within our means.