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?

Dear Gentle Sir:

Crustaceans form their exoskeletons from chitin, a leathery carbohydrate reinforced with calcium carbonate.

Without the calcium carbonate, as happens just after a molt, a crustacean is considered "soft-shelled." Some crustaceans eat their old shells to regain a measure of calcium so as to harden themselves. In an aquarium, where that might not be tenable, what is one to do?

One solution that was popular in the Eighties was to add milk to the aquarium. This was at the height of the American Dairy Council's "Does a Body Good" campaign, when the dairy industry was trying to create new markets. They introduced "Milk-for-Fish" to the pet trade in 1985.

Unfortunately for crustaceans in American aquaria, milk in the water had several undesirable side-effects. First, milk is slighly acid, which sent the pH levels of tanks off. Second, crustaceans can only absorb calcium by ingestion, so passing milk through their gills did nothing but make them breathe lactose and milk fats all day long.

Third, it made the aquarium opaque, so humans couldn't see their small friends and their small friends could not see one another. Fourth, it interrupted crustaceans' antennae's sensory abilities, causing them to bump into their environment drunkenly and miss out on food entirely. And fifth, it turned the water rancid and quite stinky.

After a backlash from the aquarium community, in which several lawsuits claiming false advertising were launched and several out-of-court settlements were made, the American Dairy Council withdrew their Milk-for-Fish campaign.

Since then, "calc-licks," small lumps of compressed industrial chitin by-product, have been the product of choice for crustaceans in need of a calcium carbonate boost. They can be had from your local pet store quite cheaply depending on the size.

You can also feel free to add washed shell pieces from your own shellfish dinners, something much cheaper and closer to what a crustacean might find in front of them in the wild.

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

Dear Gentle Sir:

The triop, also known as the horseshoe shrimp, lazarus shrimp, shield shrimp, tadpole shrimp, or, in Mandarin-speaking regions, as 盾蟹 (shield crab), are sixteen species between two genera under the Linnaean taxonomical system that comprise one of the oldest and most primitive crustacean groups still extant. They have not changed much in the last 220 million years.

The distribution of species is problematic in the historical context. One species, Triops longicaudatus, is distributed through central North America, all of South America, parts of Micronesia, and East Asia (though not Taiwan). Several theories have been put forth to explain such complex distributions, but each has serious flaws.

Paterson (1977) proposed a reclassifcation of extant triops species, suggesting that the distribution failed to make sense because the taxonomy was wrong. Marmur (1979) argued that the taxonomy was indeed sound but that closer study of prehistoric landmass movements was in order while Webb (1980) pushed for even more radical taxonomic reclassification.

Webb later concluded that triops were actually two species with pronounced climate adaptations causing subspeciation (1982) and made vigorous attempts at hybridization, though he sadly was committed later that year and never contributed to the topic again; Mitchell (1984) posited that the triops genera were the result of convergent evolution.

Molecular studies put an answer to the question with Capaldi (1988), who showed the lineages were quite accurate as understood. Since then other have quibbled over species and subspecies classification and discussed plate tectonics and its intersection with triops distribution.

In answer to your initial question, there are no species of triops in Taiwan, which offers a tantalizing clue to crustaceologists. Did triops never live on Taiwan, meaning the island separated from Asia before they existed? Or did triops live there for a time but, in the specialized island environment, go extinct?

Until these and other questions are answered, the multi-million year old mystery remains, tantalizing scientist and hobbyist alike. If you're desperate to see triops in Taiwan, however, try visiting some university labs, where imported speciments thrive happily. Just don't release any in the wild!

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

Dear Gentle Sir:

Those are no parasites, those are your crayfish's gills!

Sometimes, when a cray—or any crustacean—molts, the process goes awry. This can happen for a number of reasons, such as poor diet, improper habitat, distress, or unfavorable genetics. The process is torturous to begin with and is the most vulnerable part of any crustacean's life.

Of the many things that can go wrong during a molt, it is most common in crayfish for legs and antennae to become suppressed or mangled. Therefore it's possible in some crays for whole legs to grow underneath their shell though they remain unseen on the outside. Indeed this is how crays regenerate lost limbs.

Mismolting can result in other deformities as well, some of which can lead debilitation or death. Crayfish have been known to mismolt their tails, which means they can not escape by means of tailflapping, leaving them slow and liable to predation. A cray in a laboratory was recorded to have mismolted its eyes and spent the better part of two months blind, making it way by its sense of smell alone.

In your case, though your crayfish might look freakish and scare its other tankmates away, it will likely survive. Make sure your cray has plenty of available shelter and does not share its tank with any predacious species. If you suspect water quality being a factor in your cray's mismolt, have a batch tested at your local pet care center.

In the meantime, enjoy your cray's wonderful new plumage underwater and out of the air until the next time it molts, when the gills will hopefully become enshelled again.

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

Dear Gentle Sir:

Despite the term "Lazarus" used to describe triops, there are no triops fossils in Israel. One was discovered in Jordan in 1922 by Dr. Abraham Müller of the Freie Universität Berlin in strata some twenty-two million years old, though its species and genus were never verified.

Despite this dearth of triops fossila, a fun experience for your children can still be had due to the short lifecycle of the creatures. Simply order a triops kit from your favorite online retailer and follow the instructions. In the course of several months your children can chart the birth, life, death, and "fossilization" of their own triops.

In whatever container your grow your little friends, include a layer of clay or mud and sand at the bottom. Once the triops die, leave their tank in the sun until the substrate is completely dried. With a toothpick, paintbrush, and magnifying glass, your children can unearth the triops exoskeletons.

Just like a real paleontologist, carefully piece together shell fragments and any other items of interest. Can your children guess from the "fossils" alone what the creatures ate? How they moved? Reproduced? How did they breathe? Of course your children know these things from watching the creatures while alive, but looking back through the "fossil record" here will be a rewarding experience.

And of course, once finished with your dig site, add some water and watch triops hatch anew, just like the real Lazarus!