BIOL 305 Crustaceans

Crustacea

• 2 pairs of antanea (di-antennata)

• extant forms have 16-20 segements, various degrees of tagmosis, often cephalothorax

• often with carapace (dorsal cuticle of head extenfing to thoracic an abdominal segments

• nauplius larva

Relevant classes of crustacea

• Branchiura: fish lice

• Malacostraca: crabs, lobsters, shripms, scuds, krill, woodlice

• Copepoda: copepods (zooplankton)

• Cirripedia: barnacles

• Branchiopoda: benthic and planktonic crustaceans

• Remipedia: elongate, blind, cave-dwelling crustaceans

Malacotraca

• includes decapoda and isopoda

• appendages can be specialized to many functions

copepode body plan

• head fused with 2 anterior thoracix segmenets (2 antennae plus mouthparts

• 5 free thoracic segments with limbs

• 5 abdominal segments without limbs

isopod body plan

• head wiht 2 pairs of antennae, maxillae, maxillipeds

• reduced carapace

• 7 thoracic segments with uniramous limbs

• 5 abdominal segments with biramous limbs (swimming and respiration)

• abdominal limbs bear ‘lungs’ in terrestrial isopods

Cirripedia body plan

• head reduced, animal glued to substrate by cement

  glands at bases of first antannae

• carapace a ring of protective plates ‘shell’

• 6 thoracic limb (cirri) rake partcles from water

• abdomen highlu reduced

Cladocera ( a Branchipod) body plan

• carapace covers thorax and abdomen

• second antennae large, powerful, used for swimming

• 6 pairs of thoracic limbs (filtration apparatus for plankton food)

• abdomen highly reduced

Remipedia bodyplan

• head with 2 pairs of biramous antennae

• raptoral cephalic limbs

• many trunk segments with biramous paddle-like limbs

• no post-cephalic tagmosis