Who Gives A Fish Forums

Wondering if the hermit crabs I find on the beach are suitable for my marine tank.

I'm inclined to think you might not be allowed to collect them, there could be regulations in place.

I'm no expert on UK wildlife, but based on my own country's coastal fauna, I'd expect those hermit crabs to be quite large and carnivorous. They're likely adapted to temperate conditions, so I'm not sure they'd thrive in tropical temperatures long-term.

zenoxa wrote: ↑Tue Dec 10, 2024 4:26 am I'm no expert on UK wildlife, but based on my own country's coastal fauna, I'd expect those hermit crabs to be quite large and carnivorous. They're likely adapted to temperate conditions, so I'm not sure they'd thrive in tropical temperatures long-term.

Does that include seaweed? I was thinking of using a handful of the stuff, possibly a type of macro algae, in a sump or maybe even a display tank with seahorses or some kelp forest inhabitants. I'm based on the southern UK coast and recently had a dive experience where the water was a relatively balmy 12 C - warm and cosy compared to the winter months when it drops to 6-8 C. It was chilly on the lips, but the scenery was beautiful in its own right, with a seaweed and crab-dominated reef that was quite different from a tropical coral reef. The aggressive crabs were a bit of a surprise, but it's got me thinking about setting up a biotope. The temperature might be too different for mixing with tropical species, but it could be an interesting project.

Regards

I also think Zenoxa has a point about the UK species, likely anything collected from those cold waters wouldn't last in our tropical tank temperatures. The critters you find up there just aren't adapted to the tropics.

I'm also a south coast resident and have experimented with keeping larger seaweed and bladderwort in my tropical tanks. Unfortunately, it didn't work out long-term. The bladderwort managed to survive for a few weeks, but it grew slow and distorted due to insufficient light, and pieces would break off and rot. You'll also need a large clean-up crew initially, as most of these seaweeds come with a white slime that seems to be a bacteria that goes wild in warmer water - it doesn't appear to cause harm, but my clean-up crew loves feasting on it and gets rid of it quickly.

As an avid snorkeler, I used to explore the waters off Portland from May to November almost daily. The experience was stunning, despite the occasional ice cream headache in the early months. I even considered setting up a cold-water native marine tank, but it never materialized.

I've found that the red fine branching algae - the stuff that wraps around your legs when exiting the water - is a hit with Sea Hares, but hermit crabs love it just as much. Unfortunately, it never lasts more than a few hours in the tank without being devoured. However, it does display a vibrant fluorescent red-orange color under actinic lighting.

I wouldn't recommend adding this algae to your tank unless you plan to use it as a food source. On the other hand, the crabs and snails I've collected from under rocks have been great for feeding my Puffer.