Free images of Arthropods
Did you know....
that the organisms in the phylum Arthropoda, make up more than 75% of all life on Earth? Wow!
The term "arthropod' comes from the greek words "arthro" meaning "joint" or "jointed" and "pod" meaning "foot".
According to the Linnaean system of animal classification, species that are related are grouped into "genera" (singular of term genus); genera are grouped into "families"; families into "orders"; orders into "classes"; classes into "phyla" (singular of phylum). The images in this photo category all belong to the phylum called "Arthropoda" or Arthropods.
Within the phylum Arthropod, are five major groups or subphyla:
Include a diverse group of species having bodies divided into two segments - the prosoma and the opisthosoma. Note, unlike most arthropods, Chelicerates, don't have antennae. Includes Arachnids (spiders, scorpions, ticks, mites) and horseshoe crabs.
Include over 31,500 living species. Includes crabs, lobsters, shrimp, pill bugs, crayfish & barnacles.
The insects. There are over 800,000 species! Includes multiple Orders with species like ants, bees, beetles, bugs, butterflies, cockroaches, etc. etc.
Insects have bodies that have three distinct regions: the head, thorax and abdomen. The head has one pair of antennae and most have one pair of compound eyes and some simple eyes called "ocelli". Insects may bite, suck, stink or lick. Insects typically have three pairs of legs but some may have fewer legs or be legless. Often they have one or two pairs of wings, but some are wingless.
Includes over 13,000 species. This group includes species with many legs. Long, worm-like bodies may be microscopic or a foot in length. Among others, include Diplopoda (millipedes) and Chilopoda (centipedes).
Trilobites - Now extinct.
Arthropod distinguishing features:
Bilateral symmetry -
Left/right body symmetry. One half of the body mirrors the other.
This is an external skeleton - think of it as body armour. It is a tough outer covering made up of a series of ring-like segments and plates. The bodies of arthropods are supported by their exoskeletons - they do not have internal bones. The exoskeleton is made out of "chitin" and is sometimes called a "cuticle" (the same material your fingernails are made from). In order to grown, all arthropods must shed their exoskeletons and produce new, larger ones.
Segmented Body -
body with multiple segments. Most arthropod's have three sections -
the head, thorax and abdomen. Each segment having a pair of
appendages. Appendages may be antennae, wings, legs or mouth
parts. Segments are connected with movable joints.
The trouble with constantly wearing a suit of armour, is flexing your appendages. Conveniently, all arthropods have jointed limbs allowed them to be bent.
May limbs or pairs of limbs -
Multiple body segments often have a pair of limbs on each segment. Spiders have 8 legs, millipedes have hundreds!
Arthropod Image Categories