phylum arthropoda animals with jointed appendages
DESCRIPTION
Phylum Arthropoda animals with jointed appendages. includes insects, crustaceans, centipedes, millipedes, and arachnids exoskeleton made of chitin must shed shell to grow. Chelicerates. Includes spiders, ticks, scorpions, horseshoe crabs, and sea spiders Six pairs of appendages - PowerPoint PPT PresentationTRANSCRIPT
Phylum Arthropoda animals with jointed
appendages
• includes insects, crustaceans, centipedes, millipedes, and arachnids
• exoskeleton made of chitin• must shed shell to grow
Chelicerates
• Includes spiders, ticks, scorpions, horseshoe crabs, and sea spiders– Six pairs of appendages– One pair of chelicerae (for feeding)
Horseshoe crabs
Sea spiders
Mandibulates
• Crustaceans– Decapods
• Crabs, lobsters, shrimp
Durban Dancing Schrimp
Crustaceans• The crustaceans are a large group
of arthopods–Lobsters–Crabs–Shrimp–Crawfish–Barnacles–copepods– The majority are aquatic, living in
either freshwater or marine environments,
– Some are terrestrial
Crustaceans Continued
• The majority move about independently• a few are parasitic and live attached to
their hosts– Sea lice, fish lice, whale lice (crustacean lice)
• adult barnacles live a sessile life — they are attached head-first to the substrate and cannot move independently.
Sea lice are parasitic
Structure of crustaceans • Crustaceans have three distinct body
parts: – head, thorax and abdomen
• the head and thorax may fuse to form a cephalothorax
Structure continued
• The head has two pairs of antennae, one pair of compound eyes and mouthparts– Mandibles– maxillae
• Each body part usually has a pair of appendages– chelipeds– Walking legs– swimmerets
Molting
• Like other arthropods, crustaceans have a stiff exoskeleton which must be shed to allow the animal to grow or molt.
Reproduction
• crustaceans all have a larval form known as the nauplius
• most crustaceans have separate sexes, in many decapods, the eggs are retained by the females until they hatch into free-swimming larvae.
Crustaceans of the Gulf of Mexico
• Decapods – Shrimp– Crabs – Lobsters and
Lobsterettes– Hermit crabs – Squat crabs and Porcelain crabs
Common Name of some species
American Spider Crab Sentinel Crab
Pebble Crab