Cheliceriformes

subphylum of Arthropoda including classes Chelicerata and Pycnogida

Uniramia

subphylum of Arthropoda including classes Insecta and Myriapoda

Crustacea

subphylum of Arthropoda including classes Branchiopoda (brine shrimp), Maxillopoda (barnacles and copepods), Ostracoda and Malacostraca (crayfish, krill, prawns, crabs)

-sexual internal fertilization -planktonic larvae

-50k+ species -mostly marine, use gills

-well-developed vision and nervous system

-complex social behaviors

Chelicerata

class of subphylum Cheliceriformes including subclasses Arachnida and Merostomata

Arachnida

subclass of Chelicerata including spiders, mites, ticks and scorpions, characterized by four pairs of legs, mostly carnivorous diet and a MO involving sting prey to induce paralysis, injecting with digestive fluids and ingesting liquid food of predigested animal/blood

Merostomata

subclass of Chelicerata characterized by the ancient horseshoe crab, found on the sandy, shallow Atlantic coasts off of the Eastern United States and SE Asia

Pycnogida

class of subphylum Cheliceriformes including sea spiders, which live on soft-bodied inverts such as sponges, jellies and anemones

Insecta

extremely diverse class of subphylum Urinamia including almost 1 million known species, characterized by three pairs of legs and two pairs of wings, they are relatively rare in marine systems

Myriapoda

class of subphylum Urinamia including centipedes and millipedes