Transcript The Crayfish

Understanding the Arthropods
Curtz 2011
Arthropods
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Phylum- Arthropoda
Subphylum- Crustacea
More than 1.1 million species of arthropods.
They have achieved the greatest diversity, although few can live
in salt water.
Zooplankton- is formed by most marine arthropods during their
larval stages.
All land and marine arthropods have a external skeleton,
segmented body, and jointed appendages.
Some have the ability to live on land and water.
Anatomy
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Many Arthropods look different; however they all have an
(exoskeleton), which is an external skeleton.
They have a segmented body and jointed appendages.
Muscles are attached across the joints to facilitate movement.
The body cavity contains the internal organs and fluid that is
equivalent to vertebrate blood, which is pumped by the heart
around the body in an open circulatory system.
Most marine forms use gills for respiration and have welldeveloped sense organs.
Anatomy & Growth
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Can ‘regenerate’– they have the ability to regrow practically
any appendage that gets broken off.
i.e.-legs, claws, antennae, even eyes if they happen to
get
snipped off in a fight.
Can ‘moult’- as the crayfish grows it sheds its exoskeleton in
a process known as (moulting).
Shortly after a moult, the new exoskeleton is very soft,
making the crayfish much more vulnerable to predators.
A crayfish may moult many times in its life.
The average crayfish only lives about two years.
Habitat & Feeding
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swamps, streams, and lakes.
They will often conceal themselves under rocks or logs
to hide from predators or to ambush prey.
They are most active at night, feeding on snails, algae,
insect larvae, worms, tadpoles, and occasionally
minnows.
They will also eat decaying plant matter and debris.
Reproduction
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Have a high-volume reproduction rate.
Mate in October or November and the eggs will be laid in the
following spring.
The female will attach the eggs to her swimmerets, use her
tail as a protective flap, and carry the eggs around with her
until they hatch.
A female may lay 10 to 800 dark brown eggs.
References
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undefined. (undefined). The Town of Lake Lure. In
Aquatic Life: Arthropods - Crayfish. Retrieved April. 25th,
2011, from
http://www.townoflakelure.com/aquatic_arthropods_cra
yfish.htm.
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Frances, Peters & Gavira Guerrero, Angeles. (2008).
“Ocean; The word’s last wilderness revealed”. In Ocean
life; Arthropods. DK publishing, New York, NY. Pg. 292294.