Horseshoe crab question

[Phantom7]

Hello! Yesterday I went to my lfs with the intentions of grabbing an anenome and 3 peppermint (hoping they’re true) to deal with my very mild aptasia issue I’ve had for the past year in my 120. Knowing myself, I walked out with 6 peppermint, a urchin, and a horseshoe crab.

i purchased the horseshoe crab after being told they’re easy to care for, are extremely active, and will work well in my tank (and most importantly not bother any of my current inhabitants like my goby). My father was also really interested in it, and I try to put things in my tank everyone enjoys.

I got home and put everything straight in after acclimating (was told to skip quarantine on everything since they’re invertebrates) and the crab instantly buried himself. I figured he was just scared and needed some time to work his self out, watch the urchin pick up a shell to wear, and didn’t think anymore of it. Later in the night I started doing more research on him and figured out he may not be the best for my aquarium, so I took him back to return him. (I read they kill beneficial things in the sand bed)

anywyas, trying to skip over parts to make this shorter, I was basically told that they only eat bad things like bristle worms (aren’t those good??) and won’t starve themselves because the bacteria will grow quicker than they will eat it, and was basically told they’re an amazing addition to my tank, and the urchin will do more damage than the crab.


TLR My question is did I make a mistake returning this crab, or are they just trying to get a sale? Also, anything I’ve read seems to speak well of urchins, will it harm things in my sandbed like they said?

apologies for the ‘book’.

Edit: it seems my TL: DR has been substituted for a smiley face. Interesting, leaving for humor.

 

[Pistondog]

Horseshoe crabs get pretty big, 18 inches.

 

[BurlyWizard]

Horseshoe crabs get very large, just google them to see them in the wild. That being said, they likely won't make it to die of old age in the home aquarium. They naturally exist in the substrate, so it wasn't digging down there out of fear, that's likely where it would have spent much of its time. They have been known to knock over rocks and stir up bacteria in the sand in home aquariums (due to essentially living as a sand-submarine).

They are very cool to look at and even pick up, and the adults in the wild have a fierce / creepy vibe to them. That being said, most aquarists will recommend against attempting to keep one in a home tank, and I think you did the right thing.

 

[CMMorgan]

Hi there, I worked at an environmental center for 5 years. We had a horseshoe crab "touch tank". Let's skip the part about why touch tanks are a bad idea and go directly to the horseshoe crab information. I maintained that tank and gave tours and lessons to groups.

They stay buried most of the time... moving around the tank like little bulldozers. (very slow moving bulldozers)

They need food. We used to put shrimp, etc. just under the tips of there shells to make certain everyone ate. Like puppies... they got very active when dinner was delivered.

They can get huge...like dinner plate huge. Not overnight but in the proper environment... which is not an aquarium.

They need stable and clean water conditions. (circling back to touch tanks being bad ideas)

Fun facts: they are genetically closer related to spiders than crabs and the blood of horseshoe crabs is actually used in treatments for people with hemophilia.

Simply put... they do not have a place in our little aquariums. I wish they did because they were my favorite residents in all of our aquatic exhibits.

 

[Pistondog]

Hi there, I worked at an environmental center for 5 years. We had a horseshoe crab "touch tank". Let's skip the part about why touch tanks are a bad idea and go directly to the horseshoe crab information. I maintained that tank and gave tours and lessons to groups.

They stay buried most of the time... moving around the tank like little bulldozers. (very slow moving bulldozers)

They need food. We used to put shrimp, etc. just under the tips of there shells to make certain everyone ate. Like puppies... they got very active when dinner was delivered.

They can get huge...like dinner plate huge. Not overnight but in the proper environment... which is not an aquarium.

They need stable and clean water conditions. (circling back to touch tanks being bad ideas)

Fun facts: they are genetically closer related to spiders than crabs and the blood of horseshoe crabs is actually used in treatments for people with hemophilia.

Simply put... they do not have a place in our little aquariums. I wish they did because they were my favorite residents in all of our aquatic exhibits.

And their blood is blue and copper based rather than iron.

 

[CMMorgan]

And their blood is blue and copper based rather than iron.

That is correct. Fascinating little creatures!!

 

[Phantom7]

Horseshoe crabs get very large, just google them to see them in the wild. That being said, they likely won't make it to die of old age in the home aquarium. They naturally exist in the substrate, so it wasn't digging down there out of fear, that's likely where it would have spent much of its time. They have been known to knock over rocks and stir up bacteria in the sand in home aquariums (due to essentially living as a sand-submarine).

They are very cool to look at and even pick up, and the adults in the wild have a fierce / creepy vibe to them. That being said, most aquarists will recommend against attempting to keep one in a home tank, and I think you did the right thing.

Thank you for your input. And yeah that’s something I learned the hard way- them living in the sand. At the store they don’t have a deep sand bed (or really one at all) and they seemed really active like the guy had said. I stirred up 3/4 of my sand bed looking for him, and the tank is still a little cloudy.

 

[Phantom7]

Hi there, I worked at an environmental center for 5 years. We had a horseshoe crab "touch tank". Let's skip the part about why touch tanks are a bad idea and go directly to the horseshoe crab information. I maintained that tank and gave tours and lessons to groups.

They stay buried most of the time... moving around the tank like little bulldozers. (very slow moving bulldozers)

They need food. We used to put shrimp, etc. just under the tips of there shells to make certain everyone ate. Like puppies... they got very active when dinner was delivered.

They can get huge...like dinner plate huge. Not overnight but in the proper environment... which is not an aquarium.

They need stable and clean water conditions. (circling back to touch tanks being bad ideas)

Fun facts: they are genetically closer related to spiders than crabs and the blood of horseshoe crabs is actually used in treatments for people with hemophilia.

Simply put... they do not have a place in our little aquariums. I wish they did because they were my favorite residents in all of our aquatic exhibits.

Thank you for such a detailed response! I couldn’t imagine having to find this little guy in my sand bed every night to feed him. I spent probably 30 minutes not trying to disturb everyone that badly, though my tank looks horrible. I’ll have to let the goby disperse the sand how he likes it