25 Apr 2007

Hermit Crab Nudity

Dear Blue Lobster:

don't you think hermit crabs when they are out of the shell are disgusting? they gross me out

alison

Dear Gentle Sir:

The hermit crab is an ancient creature representing the superfamily Paguroidea and its seven families that has existed for some 70 million years.

In the hermit crab's unique evolution it came to depend on ammonite and gastropod shells to serve as auxiliary protection. As they evolved, however, their tails became completely soft and the hermits then needed to house their now-vulnerable abdomens within shells. Only the Coconut Crab (Birgus latro) is capable of roaming free.

Humans first noticed the hermits' "nudity" and exploited its potential symbolism over 30,000 years ago when tribes of aborigines in Australia used them in fertility rituals. The men of the tribes would hold a crab to their genitals where it would clasp on with its claws. They would then dance about until a woman gave them a shell, into which the hermit would move.

As clothed, shameful human beings, any animal that appears "naked" — be it a shaved dog, a shedding snake, or a hermit after molting — unnerves and distracts us. But unlike we humans, other animals don't perceive nudity. The only animal with a problem here is the human one.

I recommend you spend some time with your hermit completely nude. Strip completely naked and take your hermit out of his terrarium. Stroke his shell and antennae and tickle his chin. Let him, in turn, crawl around on your prone body: the arch of your back, the crease of your upper thigh, your underarm.

As you explore one another's bodies realize that clothes are just another version of the hermit crab's shell, temporary and deceptive, and that shame of nudity is a yoke of societal concern — not one for you and your crab.

18 Apr 2007

Why Are Crays Eating My Waste?

Dear Blue Lobster:

I specialise in waste treatment facility discharges, inspecting large-volume fluid discharge systems to ensure that everything is running smoothly in terms of mechanical structures, flow paths, and artificial and environmental blockages in flow systems.

Crayfish have begun to make their way up into the facilities. They occasionally need to be purged when the crayfish buildup becomes too dense. If crays were there just to harvest nutrients from the waste, why is it that is no other wildlife to be seen other than these crays?? I am stumped.

Best regards,
Benjie Saunders

Dear Gentle Sir:

Your problem is a puzzling one. You don't mention your geography, but crayfish in general are opportunistic scavengers and so would be attracted to any palatable biomass which became available in their habitat. The factor that does not make sense is the human feces, which crays do not regard as food.

Despite the fact that crayfish feed on rotting organic material, they are not coprophages. The bulk of human feces is bacterial matter and that, combined with the fact that the human gut is efficient at absorbing nutrients from food before it is passed, leaves only a few possibilities to explain your cray problem.

One is that the waste you are processing is not simply solid human waste. Are there perhaps cat or dog feces in the mix? Their high protein content would attract crays. Has there been a large epidemic of diarrhea recently? Undigested materials passed in leaky stools would afford the cray nutrients by the gallon.

Perhaps the best measure is to chemically examine the sludge and, once certain properties that might attract crays are established, track down the source of the attraction. In the meantime, a shovel or spade and a good tight wetsuit are in order. Good luck!

11 Apr 2007

Crustacean Acne: White Spot Disease

Dear Blue Lobster:

My shrimp Arty has white spots they look like pimples i think he is embarrassed because he doesn't eat much and twitches a lot. please help if you can i want him to grow up big so i can eat him.

dirk

Dear Gentle Sir:

Your shrimp does not have acne; in fact, crustaceans are immune to that disease thanks to their tough shells. Instead, your shrimp has what is known commonly as crustacean acne or bug blight, but is known in veterinary circles as White Spot Disease.

White Spot Disease is caused by Topicalis albinus, a fungus not unrelated to the band of fungi that cause our own Athlete's Foot and ringworm. In crustaceans, the fungus grows in the soil and during the warm months releases spores into ponds, streams and lakes where they then infect crustaceans.

The fungus enters through the mouth parts or any holes or abrasions in the shell. After it has infected its host, the fungus enters a secondary life-cycle where it releases spores to the lake or stream through the crustacean's exoskeleton, where the fungus then finds its way back into the soil. The spores are the small white spots we see in our pets.

The only treatment for White Spot is copper, which kills invertebrates in high enough concentrations. The trick is avoid killing your shrimp at the same time. Begin by droppering in copper aquarium medicine a few drops at a time. Use a snail as your "canary," as it will die when the concentration is high enough to kill the fungus but before your crustaceans succumb.

Another tactic is to remove the infected crustacean from your tank, scrub it with low-grit sandpaper or pumice stone, and restore it to a fresh change of water. Some owners of large lobsters and crabs have used electric grinders as well. If the crustacean is too sick or young, however, the abrasive nature of this treatment may well tear it to pieces. Use caution when scrubbing!

One thing to keep in mind is that crustaceans with White Spot Disease are highly toxic. Never ingest one even after thorough boiling. You may catch an internal form of the fungus, a serious and potentially chronic medical condition requiring copper treatment that can result in topical patina.