8 Dec 2002

Normal Behavior for Baby Crayfish

Dear Blue Lobster:

What is normal behavior for a baby crayfish? The babies hatched ~1 week ago and now they stopped moving, turned onto their sides and have turned red. Are they alive? Is this normal? What should we do? What do the baby crayfish need to eat?

Dear Gentle Sir:

It is with a heavy heart that I inform you that the state of your baby crayfish (called craybies in scientific circles) indicates that they are, sadly, expired. Moved on to that big freshwater tributary in the sky. Dead.

To directly answer your question, however, typical behavior and appearance of craybies is as follows. For the first week after hatching, they will stay on their mother's underside, and eventually grow bold enough to explore on their own, though always returning to their mother. After another week or so, they will be off on their own, independently foraging for detritus on your tank's bottom.

I wish to express my deepest sympathies and regrets to you, gentle sir, and hope that you can grow beyond this holocaust of dead baby crayfish scattered all over your aquarium and one day attempt to live again without the constant gnawing guilt of a thousand weeping souls.

You, and your silenced children, are in my prayers.

4 Dec 2002

Electric Blue Lobster Tips

Dear Blue Lobster:

Hello, I have just recently bought an Electric Blue Lobster , and I am trying to find out how to care for it better. The pet store in which I bought him at was not very helpful. I have him in a 5 gallon tank filled with water (I got the gallon sized bottled water) with some rocks, and his food, which are some shrimp (go shrinp) and a feeder fish. I got the e-care book, but it only gives refernce to Crabs. What size tank should I get, does he need heated water, a misting bottle, air pump. I don't know much from what they told me at the pet stor. What is molting also. I know this seems like a lot but, I have been everywhere for this kind of information. Please help. Thank you. Happy Holidays!!

Dear Gentle Sir:

Generally, the larger an area you can give your Electric Blue Lobster (probably actually either a procamabrus alleni or an orconectes immunis), the better. That being said, for practical purposes a 10 gallon take will suffice for the single specimen and a 20 gallon tank would be ample.

The water in the tank, which optimally should be seasoned for a few weeks before you introduce the cray, must be free of all sanitary chemicals. Chlorine and chloramine, often found in tap water, are cray-killers. A temperature of 70 degrees with a pH of 7.0, or neutral, will make for a very stable and comfortable environment for your blue lobster. An air pump of some sort should be used in the tank, if not a substratum filter. Oxygen is important to crayfish.

As for molting, good sir, it is the natural process by which crayfish (as well as other crustaceans) shed their hard exoskeleton in order to grow. The process is preceded by strange eating behaviors and activity patterns. The shell will split at the carapace and the cray usually escapes through the top of the tail. During this stage the lobster is vulnerable and will hide for a few days, and is why it is important that there is plenty of space and hiding places in the tank: predacious fish species as well as other crays will consider the molted lobster as prey! After hardening the new, larger exo-skeleton, the crayfish should begin eating normally. You may also notice that any missing or injured limbs have reappeared in some manner after the molt.

The Embrace Question

Dear Blue Lobster:

I have two crayfish in my African cichlid tank. One is blue and has longer claws (if that's the right term), and the other is brown and has shorter claws. Do the size of the front claws indicate male and female? They have been together in the tank for a few months. Twice I have seen the longer-clawed crayfish (blue) grab hold of the shorter one's claws and hold it in what looks like a mating embrace. Could this actually be a mating embrace, or are they probably just fighting? Thanks.

Dear Gentle Sir:

To address the most important point first, no, what you are observing is not a mating embrace. It is an embrace of death, brought about by territorial disputes between the two crayfish in your tank!

I recommend either relocating one of the two crayfish, or moving the entire system to a larger tank. Crayfish are territorial and what you have seen in the past is a guarantee of oblivion for the first of these two arch-rivals the moment that they molt and become vulnerable!!!

As for the question about claw size indicating gender: no, sir, this simply indicates that these crays are of different species, and most probably different genera as well.

2 Dec 2002

My Fiddler Crab Is Losing His Legs!

Dear Blue Lobster:

please help my fiddler crab is losing his legs!i just got him 2 days ago and he is eating and acting fine (except for his leg) i also keep him in a 10 gallon tank with 1 other male crab thank u

Dear Gentle Sir:

A 10 gallon tank may be too small to keep a pair of male fiddlers in. Just because the pet store does it doesn't mean that you should!!!

Other than stress created by suboptimal territory distribution between the two male fiddlers, here are a few other points to check up on:

  1. Are the crabs being fed properly? Crustaceans are oppostunistic cannibals, and since these two males are kept closely together, territorial disputes may become occasions for quick meals.

  2. What's the water like? Check pH, temperature, and nitrate levels, all of which can affect fiddlers. Also make sure that if you used tap water for your tank, you removed the chlorine or any other sanitary chemicals from it first.

  3. Can the fiddlers get out of the water? In a 10 gallon tank, the water should be no higher than 3", with several areas the fiddlers can climb out of the water at. Fiddlers need air! Without access to air, a fiddler's health will decrease.

  4. Hiding places! Like crayfish and lobsters, fiddler crabs molt. When molted, their hard exo-skeleton is shed off and they are left vulnerable for a few days while they recalcify their new exo-skeleton. Without a place to hide while so weak and soft, they can easily lose legs from competing fiddlers or any other predacious species in the tank.