crustaceans

what are the major characteristics of crustaeca?

tripartite brain, mandibulate structure of ommatidia, naupilus larvae, compound eyes, two pairs of antennae, mandibles, and maxillae

what is the general life cycle of crustaceans?

egg → nauplius → protozoea → mysis → postlarval stage → adult

what are the characteristics of branchiopoda?

flattened leaf like legs called phyllopodia as respiratory organ, reproduce by parthenogenesis, generally freshwater, carapcace, no abdominal legs, second maxillae reduced or absent, genital appendages on first abdominal segment

what are the characteristics of ostracoda?

enclosed carapace, benthic or climb on plants, some burrow or are planktonic, males emit light to attract females, fusion of trunk segments

what are the characteristics of copepoda?

antennules longer for swimming, small and lack carapace, genital appendages on first abdominal segment, naupilus eye, no abdominal legs

what are the characteristics of thecostraca?

carapace surrounds body, head reduced, abdomen absent, jointed cirri with setae, maxillipeds, tagmata of thorax and abdomen, sessile, parasitic

what are the characteristics of malacostraca?

largest class, head with 5 fused segments and non-segmented rostrum, thorax with 8 segments, abdomen with 6 segments, teslon and uropods form tail fan

what are the characteristics of decapods?

5 pairs of walking legs, 3 pairs of maxillipeds, crabs, crayfish, lobsters, and true shrimp

mandibles

on head, aid in swimming and chewing

maxillae

on head, cut food into smaller pieces and can be modified suction cups

maxilliped

feeding appendage modified from thoracic limb, hold and crush food

swimmerette

small appendages underneath animal for swimming and carrying eggs

chitin

secreted cuticle, made of protein and calcareous material

tagmata

head, thorax, and abdomen

rostrum

anterior end of animal, non-segmented

telson

posteriorly, last abdominal segment, part of tail, and bears anus

uropod

posterior appendage, forms tail fan, and function in locomotion

carapace

dorsal cuticle of head, covers most of body

tergum/pleurite

dorsal cuticular plates/lateral plates

hemocoel

major space filled with blood

green gland (antennae/maxillary gland)

tubular structure at ventral part of head

end sac

excretory organs and space around gonads

statocyst/statolith

opens at base of first antenna in crayfish, contains ridge that bears sensory setae/important for balance

ommatidia

compound eyes with photoreceptor units

nauplius

larval form with antennules, antennae, and mandibles that aid in swimming

parthenogenetic

self-reproduction in which egg cells develop into offspring without presence of mate

cirri

jointed with setae that feed and filter small particles

kentrogon stage

product of rhizocephalan parasite, after infection stage in females, injects parasitic cells into hemocel of host