Crustacean Adventures

Hello all! As probably none of you know (;), I have been eying crabs for a while now. No, not your typical hermit crabs or other marine aquarium crabs, though those are awesome too. Rather, my interest has grown in freshwater/brackish terrestrial crabs, specifically of the genus Geosesarma.

Bam! Surprise Photo.

I have always had an interest in these fascinating freshwater denizens, but doors started to open in regards to their availability after I saw a 1:1 pair of vampire crabs come up for sale/trade on Arachnoboards. I eagerly contacted the seller, and soon we had a trade worked out. Unfortunately, one of the specimens died before we shipped out, and since I was primarily interested in breeding them (which you can’t do with only a male), the trade fell through.

However, sometime after, I discovered one of my friend’s, also interested in the obscure invertebrates of the world, already had two species of Geosesarma! He let me know that he was able to order more, and that if I wanted some to let him know. Long story short, I ended up with 5 Geosesarma dennerle, two females and three males (the shipment was male-biased), of an odd color variation! They seem to lack a full splotch of yellow on their carapace, a usual characteristic of G. dennerle, rather appearing to somewhat retain their juvenile coloration of just splotches of yellow/whitish-grey. Then again, a few of the specimens still are juveniles starting to transfer into adulthood, so we’ll see how it pans out with them.

Geosesarma sp. definitely are on the small side, and all of my specimens are only about 1.5″ in terms of leg span (that’s about 3.81 cm for all you people on the metric system), but what they lack in size they make up for in coloration, behavior, and ease of breeding. They are one of the few crab genera to breed fully in freshwater, with the females giving birth to fully-formed baby crabs! They also are very communal, making it even easier to breed these awesome crabs in captivity.

I already had an empty 20 gallon (75.70 liters) paludarium, purpose built for vampire crabs a few months before by my insanely-skilled brother, calling for some inhabitants, so I’m sure you can guess where they are being housed…photos below!

Yellow variant.
Much lighter variant, with almost white eyestalks.
Each crab has its own personality of sorts, and this female specimen has proven to be the boldest of them all, regularly venturing out into the open. Normally they hide until the observer is gone and movement is no longer visible, but not this crab.

The paludarium. A small water feature, kept moving by the small waterfall of sorts coming out of the rock on the left, is kept hard by the presence of calcium carbonate coral sand and a few coral rocks. Soft water will lead to deformities in the crabs.

On land there is a plethora of plants, Cissus discolor, Selanginella sp., Pepperomia rosso, Epiperemnum aureum, and various other unknown plants in both the soil and in the water. My skill with plants is not where I’d like it to be yet…

Everything has been happy and growing, with one plant even flowering. The crabs have done quite a bit of rearranging however, including exposing the tubing and blue foam underneath the substrate in several areas. Also, besides eating their regular food of springtails, dwarf isopods, and biodegradable peat pots (a trick shared by the above mentioned friend), they have also decided they like the taste of both decaying and growing moss, and the leaves of the fern in the back left of the second paludarium photo. They crawl up the leaves of what looks like a lemon plant in the mid-left of the same photo, and then strip off the low-hanging fern leaves. Considering this fern has been the most sensitive and difficult plant to get growing, I can only say that I am mildly frustrated with their sudden favorite food. But just so long as the crabs are happy, I’m happy, ha ha.

And there you have it! My crustacean adventure as of now. My plan is to breed them if you haven’t picked that up yet, and hopefully start to increase the numbers of captive bred specimens available in the hobby. Hopefully by doing so more species will come into the hobby, including two of my favorites: Geosesarma borogensis and G. malayanum.

As always, I thank God for all these incredible creatures to marvel at. The diversity He created is truly breathtaking.

I’ll catch y’all next post!



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