Phylum ArthropodaBy: Cecelia Lounsberry and Gabe Dwyer

General Characteristics● Bilaterally Symmetrical ● Cells form up to the size of tissues and organs.● Eat everything from plants to animals● Live everywhere in land, fresh water, salt

water, and every other environment● Largest Phyla on earth 

Support System● Exoskeleton-made of protein and chitin

-used for protection-keeps joints attached-molting- sheds exoskeleton as it grows.

● usually contain a range from 3 to 300 sets of legs; usually have 2 pairs of antennae

● segmentation-head, thorax, abdomen

Digestive/Excrete System ● Eat Everything● Food enters through the mouth and flows

into the mid-gut where food is broken down and pushed to the hind gut.

● Nutrients and wastes are separated and either dispersed through the body or excreted in the form of guanine (DON'T drink energy drinks!)

Circulatory System

● Open Circulatory Systembody fluid enters pores to the organs and is propelled through arteries to the body

● Body fluid-Hemolymph (NOT blood)● Hemolymph is pumped by the heart to

sinuses called the hemocoel ● No Veins

Respiratory System

● Aquatic arthropods possess gills for respiration

● Land arthropods have a tracheae and book lungs as respiratory organs

● Air passes through the tracheae through specialized openings in the exoskeleton called spiracles

Nervous System

● Double chain of ganglia along the ventral surface of the arthropod

● At anterior end are 3 fused pairs of dorsal ganglia, constitutes the brain

● Much of the control of arthropod's activities is in the central ganglia

Reproductive System

● Most reproduce sexually○ However, some species reproduce through

parthenogenesis● Sperm are usually transferred to the female

in sealed packets called spermatophores● The paired sex organs are connected

directly to the ducts that open unto the ventral surface of the trunk

 

Hexapoda

● Includes insects ● Mostly live on land● 3 pairs of legs; 2 pairs of wings● There are more species of Hexapoda than

all other forms of life combined  

Cheliceriforms

● Includes horseshoe crabs, spiders, scorpions, ticks and mites

● Live on land or in water● Have chelicerae, which serve as pincers or

fangs.● They do not have antennae

Crustaceans

● Live in fresh and salt water environments● Crustacea is Latin for "Shell"● Shell is made of calcium, protein, and chitin● Have anywhere from 16 to 60 segments; 2-3

pairs of legs● Advanced crustaceans have pincers ● Include: Crabs, Lobsters, Barnacle, Shrimp 

Myriapods

● All Myriapods live on land● Head contains 3 appendages for eating

including mandibles (jaw like structure)● Millipedes

-less than 1000 legs (2 pairs per segment)-herbivores-among earliest animals on land

● Centipedes-1 pair of legs per segment-carnivorous (havepoison claws)