Exam 3 Ch 20 Flashcards
External features
cuticles made of chitin, protein and calcareous material. Caraspare covers most of cephalothorax
Tergum
Dorsal cuticular plate that covers each segment not enclosed by caraspace
Pleurites
2 lateral covering plates that form the pleuron
Sternum
Ventral transverse bar that lies between segmental appendages
Gonopores
Position varies according to sex and group of crustaceans
Protopod
(appendage) basal portion
Endopod
Medial
Exopod
Lateral
Serial Homology
Many biramous appendages (modified to do multiple functions) are homologous to each other. Crayfish possess most elaborate in animal kingdom
Crustacea are mostly marine…
- have 2 pairs of antennae
- mandibles
- 2 maxillae on head
- all appendages are biramous (2 main branches)
- most have 16-20 segments, but some have around 60
Cephalothorax
One or more thoracic segments are fused w head
Largest class…
Malacostraca. Lobsters, crabs, shrimp, etc. 5 heads, 8 thorax, 6 abdomen segments
Carapace
covering from dorsal cuticle of head
Hemocoel
Major body space in arthropods is a persistent blastocoel that is blood filled
Muscular system is mostly made up of…
striated muscles…flexors that draw apart towards the body and extensors that extend the part outward