10 Mar 2009

Taxicuticulary: Crustacean Shell Preservation

Dear Blue Lobster:

We have a blue lobster in our fish tank. The lobster just shed his shell. Is there a way to preserve the shell or at least the claws for our child to keep? Thank you.

27 Jan 2009

Growing Prawns in Kuala Lumpur

Dear Blue Lobster:

I accidentally came across your blog while searching for material on crayfish.

I really hope you can take the time to answer my mail, as I am really interested in raring prawn/ crustaceans (particularly crayfish) in Malaysia.

This would be a really novice question, would the American Crayfish be reared in a tropical climate ?

Kuala Lumpur has a hot, tropical climate with heavy rain storms occurring throughout the year, mostly in the early evenings. Day time temperatures can reach around 95°F (35°C).

What would be the best import species to be reared here ?

I have a piece of land, roughly 20 acres with a running stream in it, I am now really thinking hard to rear something in it.

What would your advise be if i wanted something crustaceans ?

Thank you in advance for your time,


22 Jan 2009

Milk: It Does a Body Shell Good?

Dear Blue Lobster:

I'm afraid my electric blue lobster ins't getting enough calcium, what should I feed him?

13 Jan 2009

The Torturous Train of Triops Taxonomy

Dear Blue Lobster:

Can you tell me if any species of tadpole/longtail shrimp live in Taiwan? Thanks!

mj klein

8 Jan 2009

The Case of the Feathered Crayfish

Dear Blue Lobster:

I have a 3 year old Blue Lobster named Ozzy and he just molted and now he has these weird feather-like parasites growing off the side of him. They are an inch long. They were under his shell before he molted. They look like sea-corral and have feathered fans that look like they catch microorganisms.

I was wondering if an anti-bacteria / anti-fungal medication will work eventually. It has done nothing so far.

Do you know how to get rid of them without hurting Ozzy?

I attached a picture

Ontario, Canada

30 Dec 2008

Lazarus (Shrimp) in Israel?

Dear Blue Lobster:

I am getting ready to start growing triops with the kids.

Are you aware whether there are fossils of triops in Israel? Where could I go with the kids to see them?

Thank you,

Nathan Wirtschafter
Hashmonaim, Israel

23 Dec 2008

Will My Ten-Incher Get Bigger?

Dear Blue Lobster:

I bought a blue lobster from WalMart about 3 years ago. He is now about 10 inches long (tail to claw) and still growing. How big do these get?

Bill Schamp

Dear Gentle Sir:

Without knowing the species, it is hard to say. Typically, there are only two species sold at retail chains in North America: Orconectes immunis, which reaches around 14cm (5½ in.) or Procambarus alleni, which grows slightly largers at 15cm (6 in.). Since your cray is roughly twice the length, it is possible that it's an Australian variety, as Australian species often exhibit insular gigantism. Whether it's a Cherax destructor, fabulosis, quadricarinatus, or tenuimanus, or another less common species, it could easily grow upwards of 34.5cm (13½ in.).

Since your cray is quite large and will likely grow larger, you should have a twenty gallon tank at a minimum, if not twice that. Considering the better conditions the cray will recieve in your tank, and the possibility that there are growth-inducing chemicals present in the water itself (from birth control pills, industrial runoff, etc.), your cray would be safest in a one hundred gallon tank. This would allow him or her to grow to an impressive 45cm (almost 18 inches!) and still feel unstifled. You can also create quite the reproduction of a natural environment with the extra room, including logs, rocks, shallows, and substantial flora.

In the future, when asking for help regarding a specific cray, include some documentation that might help identification. This includes some photographs from different angles, especially the cray's underside, place and date of purchase, and the common or scientific names and any other information given at the store. One may be able to deduce from some of the less direct evidence what family or genus the cray is, if not the species. This can help make any advice regarding your cray more accurate and therefore more beneficial in the care of your little crustacean friend.

16 Dec 2008

The Case of the Colorized Cray

Dear Blue Lobster:

We have an Electric Blue Lobster. He's gone through at least two molts and is if anything a much richer, deeper blue (with bright red spots in places). Does this mean he has not been artificially injected with blue dye?


Dear Gentle Sir:

Though cray owners usually complain of the opposite—their cray's colors fading into disturbing shades of slimy brown-green-grey, factors that don't include unnatural dyes or make-up can cause a cray's colors to become brighter and more pronounced.

Lighting is important. Despite being a bottom-dweller, crayfish are used to and require regular doses of sunlight throughout the year. Without this exposure, they fail to form vitamin D and other compounds necessary for robust health. With crayfish, poor health means poor color.

Your substrate can also affect your cray's coloration. Like any animal, the cray will try to blend in with its surroundings, and like some specific animals, the cray can change its coloration. If your gravel is bright, your cray is likely to become brighter over the course of several molts.

During some species' mating phase, the cray may ingest local minerals or plants to augment their look. This serves to make the cray more attractive with specific muds causing reds, blues, or yellows come out in their shell. Some species even wear algae or fungi as wigs.

Keeping a picture journal of your cray can help document its color changes. Whenever you perceive a coloration change, use your favorite webcam to take pictures. Then upload the pictures using your favorite blogging software and you can over time adjudge the what, if any, change has occurred.

22 Apr 2008

Black Market Crustacea

Dear Blue Lobster:

I was reading your web page when I came across a really neat marine shrimp, Lysmata cyanea. I figured that you might know someone that works with this particular species of shrimp or where they originate. Would you be able to help me in acquiring some specimens? Any help with this would be greatly appreciated.

Best Regards,

Dear Gentle Sir:

Many species highlighted in academic research are not part of commercial trade. These species are often rare or endangered or, in the case of new discoveries, not classified or surveyed yet. In other words, there's no commercial access to such species that are so well outside commercial aquarium trade.

That isn't to say there's no way at all to obtain specimens, however.

There is a thriving underground black market for rare and valuable crustaceans driven mostly by private collectors but also fueled in part by academia and museums: unscrupulous collectors and curators and university students, faculty, and staff. In Africa, for instance, importing O. rusticus is quite lucrative as the return on successful aquaculture in Africa is estimated to be worth hundreds of millions of euros annually, small change in comparison to other markets, but huge in the scope of source of the specimens.

The sad part about students mixing up with the seedy underbelly of animal trade is that both people and crustaceans die needlessly. Recently, pirates murdered the crew of a ship carrying several tons of O. rusticus; eight are known dead and two are missing. Last June, the crew of a trawler secretly hauling Diamond crabs were killed after engaging in a gunfight with the West African Coast Guard.

Ultimately, such disregard for animal life goes against the tenets of research and objectifying specimens leads to a loss of knowledge and endangerment of those involved, whether they are foolish undergraduates or sunburned pirates. Do not support this illicit trade and instead report it to your local authorities. If an animal is unfamiliar enough to remain outside the aquarium trade, leave it that way.

15 Apr 2008

Why Did My Fiddler Crab Die?

Dear Blue Lobster:

We volunteered to take the Fiddler Crab from my son’s in-class science project. The crab appeared to be doing well, eating and taking some dips in his “pool” of salt water. We changed his water and his food regularly. He burrowed through the substrate mixture (sand and humus?) in the bottom of his cage – and often slept under his see-through pool (the container the class used to provide salt water).

He was more lively than usual over the weekend – climbing up and over the flat seashell, ½ coconut shell, fake plant, and swimming pool.

Today, he appears liveless – he is upside down in his cage and has not moved since we woke up this am. There doesn’t appear to be any new appendages or a new crab anywhere in the cage.

Can you tell me how to tell if he is dead, molting, or already molted?

This mom is unfamiliar with fiddler crabs and wants to make sure we know what “Thunder” is doing, before assuming him dead.

Thank you.
Linda Adams

Dear Gentle Sir:

Thunder, from your description, appeaears to be dead. I am so sorry for your loss.

A crustacean's living conditions general health affect its ability to molt. Sick or otherwise unwell crustaceans molt abnormally and may not molt at all, and if a crustacean can not molt when it needs to, it will die.

When an illness or stressful situation limits the crustacean from molting, it will literally explode in its shell. The cracks induce sepsis from the numerous infectious agents now able to attack the soft inner body.

In Thunder's case, it appears that his living conditions were suitable generally and he was in more or less robust health, so what other factors might have been at play?

It is possible that, despite Thunder's well-kept tank, the stress from too many visitors kept him feeling unprepared for a molt. Did one of his numerous visitors offer him something potentially poisoinous?

One must keep in mind that Thunder might have been nearing the limits of his lifespan. You don't mention a physical description, but most Fiddlers live no more than two or three years. One species, Uca senex, lives to be seven years old in some cases, but that is an exception to the norm.

It is possible Thunder had scuttled through the greater part of his life when you inherited him, and either his own old age or the stresses of students and moving to your residence finally knocked him off.

One must not blame onesself for such tragedies, however; only in dealing face-front with crustacean rearing and death does experience build. Check out some crustacean or aquarium literature from your local library and consider your time with Thunder. The next little friend you take in will benefit.

8 Apr 2008

Sudden Crustacean Death Syndrome

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.

Looking forward to hearing your opinion,
Brett MacLean

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.

11 Mar 2008

Not So True Blue Two

Dear Blue Lobster:

Recently I bought a blue yabbie and a electric blue. I know electric blue lobsters are usually many different breeds all thrown into the same name but I have one that's exhibiting really odd coloring. He looks like the standard blue at 6 inches or so except his last molt he developed bright orange almost see through sides to his claws, the part that's stationary not on a joint.

One more thing, my blue yabbie was very brown except for his claws when i purchased him, after 5 molts he seems to be slightly turning blue and developing red spots along his tail but I'm worried if he will ever turn the bright blue or dark black I see from others pictures, and if so, how long should I expect?

Its amazing looking but I was hoping you could tell me the reason behind this. From your last posts I gather it may possibly be mating colors.

Thank you tremendously for your time and please keep up your highly informative blog.

Matthew McMullen.

Dear Gentle Sir:

Your guess of mating colors is a good one, though it's hard to tell what species you're working with as there are at least a dozen species with blue morphs; there are likely three or four times as many that just haven't been documented properly yet. One is lucky to see even the label "crayfish" at pet stores.

As to why the drastic change in color has happened so recently, another factor might be at play aside from mating colors. When cohabiting different species, mating colors can mean that the two species are attempting to intimidate one another in order to establish dominance. Since their tankmate's body shape and language aren't as expected, mating colors are a surefire way to show off.

There's no telling what direction their color changes might take unless you were able to identify what species they were; likewise their mating morphs might prove helpful in doing so.

As for worrying about the crays color changes, I would instead recommend that you sit back and watch the fireworks. Animal adaptability is a wonderful phenomenon to watch and, so long as your crays are not violent with one another, you might as well marvel at their chromatic displays.

For the record, species known to have blue color morphs include Cambarus diogenes, gentryi, and monogalensis; Cherax destructor, quadricarinatus, and tenuimanus; Orconectes immunis and obscurus; Pacificastus leniusculus; and Procambarus acutus, alleni, and clarkii.