The Armored Achievers pp. 125-131 Arthropods The Armored Achievers pp. 125-131

Arthropod Largest phylum with 1 million species (3/4 of all animals on earth) Segmented bilateral symmetry Exoskeleton that must be molted in order to grow Jointed appendages Blood-vascular system Mostly internal sexual reproduction

subphylums

Uniramia - Class Insecta 3 pairs of legs largest & most diverse group on earth rarely in the sea but live at the water’s edge Ex. Water strider

Subphylum Chelicerata

Class Merostomata “Living fossils” NW Atlantic, Gulf, Japan, Korea shallow, soft bottoms Ex. Horseshoe crab (Limulus polyphemus)

mouth carapace abdomen Book gills Inhalent current Repiratory chamber Exhalent current

Class Pycnogonida 1mm - 40cm pole to pole narrow body, proboscis, 4 very long legs males carry the eggs Ex. Sea Spiders

Subphylum Crustacea 35,000 species Primarily marine, some freshwater, semi terrestrial, terrestrial Use maxillae for filter – suspension feeding Gills – adapted to live in water 2 pair of antennae for sensory

Classes of Crustacea

Crustacean classes

Subclass Cirripedia Free-swimming larva Cement glands attach adult form to substrate (sessile) Hermaphroditic (long coiled penis) Ex. Barnacles

cirri cement gland

Subclass Copepoda Most abundant plankton, largest protein source (1st level consumer) Most are free-swimming but some are parasitic First antennae long for drag Planktonic larva of many crustacean Ex. copepods

Class Malacostraca 14 segments + a telson contains over half of all known crustaceans

Orders of Malacostraca

Order Isopoda Bottom dwellers (deep to intertidal) Herbivorous scavengers Ex. Pillbugs on land, gribbles in ocean

Order Amphipod burrowing in sandy and muddy sediments usually flattened from side to side three pairs of short tail limbs are used to flick them out of danger

decapods ‘10 legs’ largest 5 pair of walking legs - 1st pair heavier with pinchers (cheliped) Ex. Crayfish, lobster, crab, shrimp

Callinectes sapidus