Crustacea
By: Zackery Zwicker, Benjamin O’Toole, Katey Murphy, Katie Gallant
Evolutionary origin
• Attempts have been made to
construct a single hypothetical
crustacean ancestor. Such an
organism would have to possess:
“elongated body, two pairs of
appendages in front of the mouth, a
pair of mandibles behind the mouth,
and numerous trunk segments with
appendages that form a continuous
series of similar structure”
• Cephalocarida is proposed as having a
body plan from which all crustacean
features could emerge
Cephalocarida
• The earliest crustacean fossils
are ostrocods.
• There is evidence from the
Burgess shales that many
crustacean features had
already evolved during the
Cambrian Period (542 million
to 488.3 million years ago)
Ostrocod
fossil
Anatomy
• Haemocoel: The body cavity in which blood flows
• Sensory Organs: Compound eyes, statocysts (fluid filled cysts that
sense direction of gravity), tactile hairs that respond to pressure or
touch
• Respiration: Diffusion or gills
• Central nervous system: Brain and ventral nerve cord
Reproduction
• Crustacea produce from
eggs which have been
fertilized by sperm
• Most of the species are
dioecious, there is a male
and a female.
• Most species brood their
eggs, meaning they have
many eggs that hatch at the
same time.
Habitat
Crustacea live in:
• Oceans
• Fresh water
• Land
• Many crustaceans are nocturnal
• They spend their days hidden in a burrow, buried in
the sand or sleeping in a crevice.
Diet
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carnivores or scavengers
some are herbivores and detritivores
few classify as parasites
eat plants while some eat fish and other feed
from the bottom of the ocean
Species of Crustacea
• There are many species of Crustacea known,
67000, many of these are used for human
consumption
Semibalanus balanoides (Acorn
Barnacle)
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Grow up to 15 mm
Can produce up to 10,000 eggs
Sessile
No abdomen
Feed using Cirri
Talitrus saltator (Sand Hopper)
• Compressed
laterally
• “Beach Fleas”
• 8.2-6.5 mm long
• Known for hopping
patterns
Homarus americanus
(Atlantic Lobster)
• 20-61 cm
• .45-4.1 kg
• Lives in cold shallow
water
• Same Order as crabs
• Culinary Delicacy
Euphausia superba (Antarctic Krill)
• Grows to 6 cm in
length
• Weigh up to 2 grams
• Most abundant
species
• Bioluminescent
Bibliography
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http://www.reefed.edu.au/home/explorer/animals/marine_invertebrates/crustaceans
http://www.britannica.com/EBchecked/topic/144848/crustacean/33813/Evolution-and-paleontology
http://whyevolutionistrue.files.wordpress.com/2010/03/cephalocarida.jpg
http://www.nhm.ac.uk/resources-rx/images/1017/silurian-silicified-ostracod-fossil_71605_1.jpg
http://www.britannica.com/EBchecked/topic/144848/crustacean/33813/Evolution-and-paleontology