Impurest's Guide to Animals #98 - Shame Faced Crab

Well tis that festive season once again, one where we tend to overindulge much like last week’s animal the piratical Great Skua. In fact its behaviour has been so bad that it should hide its face in shame, much like this week’s creature. Hope you guys enjoy. ___________________________________________________________________

Issue #98 – Shame Faced Crab

Kingdom – Animalia

Phylum – Arthropoda

Class – Malacostraca

Order – Decapoda

Family – Calappidae

Genus – Calappa

Species – calappa

Related Species – There are 43 species of related Box or Shame Faced Crabs in the genus Calappa (1)

Range – The Shame Faced Crab is found throughout coastal waters in the Indian and Pacific Oceans

Shame on You

Shame Faced Crabs are medium sized crustaceans with a carapace width of 15cm, and a length of nearly 6cm. The outer shell is pale with orange or red mottling, and partially resembles a coconut shell, Calappa is a corruption of the word kelapa, which is Malay for coconut (2). The eyes of the crab protrude forwards, rather than upwards on stalks like some related species, due to the crab orientating its face and massive claws upwards, whilst buried in the sand during daylight.

These massive claws, and their defensive arrangement over the face of the crab are the reason the species (and indeed the entire genus) of these crustaceans are called ‘Shame Faced Crabs’. While used on the defensive during the day, often from the safety of its burrow, at night the Shame Faced Crab hunts for snails, using the highly adapted claws to prise open gastropod shells to obtain the snail flesh inside, or if this attack fails, uses them to demolish the preys protection until the shell is weak enough to open (3).

The secondary function of these massive claws, aid in respiration when the crab is buried in the sand. The huge size of the claws creates a hollow free of sand in-front of the crab’s face, allowing it stay submerged in the same spot for days before hunger or predatory interest forces it out of its burrow. Female Shame Faced Crabs lay their eggs in between June and September, with the planktonic larvae hatching sometime later.

Five to Save: #9 Crustaceans

The humble crustacean, be it crab, lobster, prawn or even isopod has long been a staple of the human diet. More than that crustaceans form the basis of the marine food web, thus supporting a wonderful array of life. Yet despite all the group gives like various other animals around the world there are many endangered species within the informal group we call Crustacea.

Giant Freshwater Crayfish (Astacopsis gouldi) Status: Endangered

Threats: Overfishing – The largest of all the freshwater crustaceans, this giant has long been harvested in its native Australia. Due to the slow growing nature of the species, as demand for Crayfish flesh soared, the population became reduced at an alarming rate. While still endangered (and threatened by agricultural runoff and drought) the Australian government has made a commitment to reduce hunting of the species until numbers return to a healthy level.

Oklahoma Cave Crayfish (Cambarus tartarus) Status: Critically Endangered

Threats: Pollution – Like the majority of cave species, the Oklahoma Cave Crayfish is very sensitive to changes in its environment. With the species living downstream from the city of Colcord, not to mention numerous farms, water quality in the crayfish’s subterranean home is changing rapidly, with the species accumulating heavy-metal and organic toxins in their blood stream

Sorocco Isopod (Thermosphaeroma thermophilum) Status: Extinct in the Wild

Threats: Habitat Destruction – One of the terrestrial isopods, this species was found in one location in New Mexico, this species lives in warm pools, despite (or maybe because of) the arid environment around it. A shift in water regime by the city of Socorro resulted in the pools being concreted over, which had a dramatic effect on the Isopod population. Reintroduction of captive populations is planned for the near future.

Vernal Pool Tadpole Shrimp (Lepidurus packardi) Status: Endangered

Threats: Recreation Activities and Agriculture – Found in warm temporary pools, and the sediment when these pools dry up, in Mexico and California, the tadpole shrimp prefers a turbid environment. As human development advances on their desert homes however, the vernal pools this crustacean relies on are destroyed. Those few (between five and nine depending on weather conditions) that remain are often disturbed by off road driving as well as pesticide spraying.

White Clawed Crayfish (Austropotamobiluspallipes) Status: Endangered

Threats: Disease – The UK’s only native crayfish, the white claw is under threat from a fungal pathogen known as ‘Crayfish Plauge’ introduced into the environment alongside its vector species the Signal Crayfish (Pacifastacus leniusculus). As well as spreading the disease, compertition from introduced Crayfish for food and breeding sites.

Bibliography

1 -www.arkive.org

2 - Calil, Bella S. (1997). "Crustacea Decapoda: A revision of the Indo-Pacific species of the genus Calappa Weber, 1795 (Calappidae)" (PDF). Mémoires du Muséum National d'Histoire Naturelle176: 273

3 -http://www.mapoflife.org/topics/topic_380_Crabs-insights-into-convergence/

Picture References

1 - http://cdn.fiboni.com/wp-content/uploads/2013/08/shy-crustacean.jpg?a0f395

2 - http://cdn1.arkive.org/media/30/3043700C-52A1-4D09-9398-25E860E6ACCF/Presentation.Large/Giant-freshwater-crayfish.jpg

More images may be added once the ‘Spam Bot’ has been fixed

Shameful really, at least next week’s issue is a lot more er terrestrial. Until then critic, comment and suggest future issues as well as making sure you check past issues in Impurest’s Bestiary.

Many Thanks

Impurest Cheese

@ficopedia, @laflux, @ostyo, @wildvine, @luna_joestar, @xwraith, @cgoodness, @ms-lola,@dboyrules2011,@quinnofthestoneage,@scavengerfist,@rocketraccoonthingy,@black_wreath,@captainmarvel4ever and @spareheadone

You were going to do what?! Shame on you!!

@impurestcheese: So this is a very snooty crab, preferring to dine on escargot. Got it. :)

For shame.

@ficopedia: He's so snooty he's hiding his face in shame

@impurestcheese: As well he should! Snooty, snooty crab!

@ostyo: What did I do?

@ficopedia: Maybe, you'll probably find that there's an evil grin behind those pincers

Was the Signal Crayfish introduced by humans? And if so, how and why?

Fungus destroys everything doesn't it?

@quinnofthestoneage: Signal Crayfish were introduced in the 50s across Europe for commercial and recreational fishing. St the time no one knew they carried plauge

@cgoodness: Pretty much, be it frog, bat, ant or lobster

@impurestcheese said:

Ah, thanks for clearing that up ^-^

@quinnofthestoneage: No Problem

@impurestcheese:

How long are they?

@spareheadone: Which one? The Giant Freshwater Crayfish is 40cm, the White Claw is only 9-11cm.

@impurestcheese:

Sorry

I meant the shame faced crab.

@spareheadone: Ah yes that should be 6cm, thanks for spotting that typo for me

Probably why you shouldn't drink and type

@impurestcheese: You were being crabby. :P

@impurestcheese:

I always feel like an ass when I point things like that out.

@ostyo: I generally am :-)

@spareheadone: Nah it's fine and most appreciated, a thousand thank yous my friend

That name... lulz.

@dboyrules2011: Shame on you, laughing at a poor wee crab

@impurestcheese: Not my fault it has a funny name. :P

@dboyrules2011: Perhaps, still is a little mean to laugh at something that could pinch your fingers

@impurestcheese: Nah, it's totally fine to laugh at something with a funny name, even if it can pinch your fingers. ;)

@dboyrules2011: You'll be sorry when it happens

@impurestcheese: Don't be so sure of it, lulz.

@dboyrules2011: Hmm

This one is kinda cute.

Also, it's disheartening to learn of how much us humans have destroyed the habitats of these animals.

@ms-lola: Yeah he is cute. And yes humanity has a lot of things to answer for in regards of habitat conservation