Dear Blue Lobster:
We purchased "Pinchy", an electric blue lobster about 7 months ago from a local fish shop.
He has been extremely healthy as far as I can see, always eating, molted about every 60 days, great colour, very active in the tank torturing our other fish. Tank is 90 gallons, pH about 6.5, temp about 76 degrees.
Last night "Pinchy" was alive and well, cruising around the tank looking for treats. This morning "Pinchy" was dead, lying on the bottom, no signs of struggle. Water is fine in the tank, nothing is broken, nothing else is dead, the other fish had not even touched him yet.
What is the average lifespan for this type of lobster? Also, anything off the top of your head that you think he may have "caught" disease-wise? It just blows my mind that he died for apparently no reason.
Dear Gentle Sir:
There is nothing more shocking than seeing your perfectly healthy little friend lying belly-up at the bottom of the tank, legs gently swaying in the current. It is this kind of unexpected, unsymptomed death in otherwise healthy individuals that is called Sudden Crustacean Death Syndrome, or Scruds for short.
As with any syndrome, Scruds describes related symptoms but not the underlying cause. In your case, Pinchy may have had several conditions, including a bacterial infection, a congenital neural disorder, or chronic aging.
The possibility of a bacterial infection here seems minimal since you describe Pinchy as being healthy and active, though sepsis-related Scruds of healthy individuals is not unheard of. It also doesn't sound like you are unfamiliar with aquarium maintenance so the possibility of a bad water change, temperature shock, or chemical poisoning seem likely.
In the case of a neurological disorder, the defect is inborn and there is no real way to prevent its onset. Crayfish family histories are so hard to track outside of a lab that buying an animal commercially is a crapshoot as far as genetic health goes. If this was the case with Pinchy, a shift in water temperature, introduction of a specific bacteria, or an slight shift in chemicals or other factors could have caused his nervous system to short circuit.
The most likely explanation for victims of Scrubs remains, however, is chronic aging. Chronic aging is a perennial issue with any life-based organism, as complex systems wear out over time due to the degradation of DNA during the replication process. You didn't mention how old your crayfish was, only that you'd had it for seven months.
Species typically sold as "Blue Lobsters" (see the end of this entry) typically live from two to four years with some captive specimens living five or six years. One notable case, a specimen named Methuselah, lived to be an astounding ten years of age and only died when an undergraduate lab tech cooked and ate him.
Size is the key to your cray's age. Anything beyond four inches is a good indicator that the cray is at least middle-aged and one can only hope for a few sweet months and expect to get them. This is one reason why buying younger crays is a good idea as you get more cray for your money; that is, until a treatment or cure for chronic aging is discovered.