Ahhhhh. It’s been a while since I’ve written!
While shopping for new things to feed my Hermit Crab army I got into reading ingredients. Specifically I wanted to avoid copper sulfate. It’s in -everything- because of what it does to food.
So what does it do? Why is it in just about everything? It fortifies food and adds mineral supplements. It’s also an antimicrobial agent and helps keep powdered foods from caking. Sounds awesome, doesn’t it? Well…not so much for many marine invertebrates. And Hermit Crabs fall into this section.
I love referring to this stuff as Cookie Monster’s ashes at work…seriously, it looks the part, right?
Why is copper sulfate bad for marine invertebrates? Hemocyanin! Most aquatic invertebrates have hemocyanin to transport oxygen instead of hemoglobin. Hemocyanin uses copper the same way hemoglobin uses iron. In nature copper is a bit rarer to find, so invertebrates absorb it quickly and easily. Because of this, long term ingestion of copper sulfate in commercial foods for invertebrates can lead to toxic levels.
Of course it’s all complex and there are way more details than what I’ve written. But the jist of this post is to avoid foods with copper sulfate when feeding your hermit crabs. There are many options to feed them: hard boiled eggs with the shell are excellent for protein and calcium, and you can give fresh fruits and veggies (wash carefully to avoid any kind of pesticides or herbicides). Remember though – small amounts! Hermit crabs tend to forage at night and you may not even notice them eating as they are small. Cutting up their meals and refrigerating leftovers can go a long way.