Please enable JavaScript.
Coggle requires JavaScript to display documents.
Subphylum Crustacea (Body Structure (Series of somites (segments) (Each…
Subphylum Crustacea
Body Structure
-
-
-
-
The two somites anterior to the head have a pair of antennae used for chemosensory and tactile senses, but also for locomotion in some --- these are the ONLY pre-oral appendages
-
The first set of post-oral appendgaes are the maxillae used to aid in feeding and/or respiration either directly or by transferring food to the mouth or indirectly by creating water currents
-
Pereopods used for walking(each associated with a filamentous gill -- located on the cephalothorax and pleopods (swimmerets) on the abdomen
In crabs, crayfish, and lobsters --- the first pair of walking legs are equipped with powerful claws chelae and the entire appendage is considered a cheliped
The last segment of the abdomen is the telson which is often flat and may have fan-like appendages attached (uropods)
Body System
Open circulatory system
If present, the heart resides in a blood filled chamber (pericardial sinus) and conveys hemolymph through a pair of ostia to the body
-
Respiration is accomplished by diffusion in smaller crustaceans or by exchanging across the many Gills
In some, the legs themselves are the respiratory surface and are called phyllopodia
-
-
-
Taxonomic Divisions
Class Malacostraca
Shrimp-like body plan, compound eyes; two tagmata (cephalothorax and abdomen)
Order Decapoda
3 pairs of maxillipeds and 5 pairs of walking legs, stalked compound eyes, heavy exoskeleton due to calcium carbonate deposits
Order Isopoda
Dorsoventrally flattened with no carapace, single pair of maxillae, non stalked compound eyes
Order Amphipoda
Laterally flattened with no carapace, single pair of maxillae, non stalked compound eyes
Order Euphausiacea
carapace covers cephalothorax and has a distinct rostrum with keel, but does not cover gills; stalked compound eyes, mouthparts and thoracic limbs are ventral
Order Stomatopoda
extremely complex and stalked compound eyes with 16 different photoreceptors; carapace leaves sides of thorax and posterior 4 thoracic segments uncovered; raptorial second pair of thoracic appendages
Class Branchiopoda
Small, mostly freshwater, diverse body shapes, minimal tagmatization; leaf-like and flattened legs aid in gas exchange, non hinged carapace or lacking carapace
Class Ostracoda
Small freshwater and marine organisms with two-part carapace hinged dorsally (clam like) attached to body with adductor muscle
Class Copepod
Freshwater and marine zooplankton, some parasitic, cephalothorax with 6 segments and abdomen with 5 segments; single naupliar eye, no abdominal segments
Class Cirripedia
Sessile, hardened plates protecting body, numerous thoracic appendages modified for filter or suspension feeding, no abdomen
-