Phylum Arthropoda “Jointed foot” Contains at least 75% of the described, living species of animals Almost 90% of the arthropods are insects Marine, fresh water, terrestrial and airborne Size range < 1mm mites to 4 m spider crabs

Phylum Arthropoda Exoskeleton (chitin) moult Jointed appendages Body divided into 2 or 3 sections Straight gut Brain and ganglia Open circulatory system Dioecious

Phylum Arthropoda Metameric segmentation Tagmatizaion

Phylum Arthropoda Cirripeds Copepods Isopods Amphipods Decapods Insects Crustaceans Spiders & Scorpions Cirripeds Copepods Isopods Amphipods Decapods

Phylum Arthropoda Class Crustacea 52,000 described species, 10 to 100 times more undescribed Most are free-living and marine Two pairs of antennae Biramous limbs Nauplius larva

Phylum Arthropoda Class Crustacea Subclass Cirripedia Barnacles Classified as molluscs until 1830 First fully studied and classified by Charles Darwin ~ 1200 species e.g. acorn barnacle Balanus sp

Phylum Arthropoda Class Crustacea Subclass Cirripedia Barnacles are shrimp standing on their head (cemented to the substrate) and feeding with their feet (called cirri)

Phylum Arthropoda Class Crustacea Subclass Cirripedia e.g. Goose neck barnacles Pollicipes sp Barnacles do not have a true heart Do not have gills, instead oxygen diffuses through their cirri Sensitive to touch and have a single eye

Phylum Arthropoda Class Crustacea Subclass Cirripedia Most Barnacles are filter feeders and use the water currents for their feeding advantage.

Phylum Arthropoda Class Crustacea Subclass Cirripedia

Phylum Arthropoda Class Crustacea Subclass Cirripedia Barnacles are sessile free living but some are parasitic (Rhizocephalans). Decapod host Only the larval form resembles that of barnacles the adults lack appendages and internal organs except for gonads

Phylum Arthropoda Class Crustacea Subclass Copepodia 13,000 described species and half are parasitic they form the largest animal biomass on earth Main contributor to secondary productivity and the carbon sink of the world oceans

Phylum Arthropoda Class Crustacea Subclass Copepodia Very small (1-2 mm) Mostly marine / planktonic Thin transparent cuticle One compound eye (red) No heart Lack gills (oxygen diffuses thru the cuticle) Abdomen has no appendages

Phylum Arthropoda Class Crustacea Subclass Copepodia Tide pool copepods e.g. Tigriopus sp Can survive freezing, high temperatures, desiccation and extreme salinity changes

Phylum Arthropoda Class Crustacea Subclass Copepodia Copepods have bristle-like setae that act as mechanorecptors. An array of such sensors allows detection of patterns of water flow around the body caused by approaching prey or predator, and the copepod can distinguish between the two.

Phylum Arthropoda Class Crustacea Subclass Copepodia Copepods are dioecious Planktonic copepods use pheromones emitted by the swimming female, which leaves a trail in the water that the male can follow to locate the female

Phylum Arthropoda Class Crustacea Subclass Copepodia During mating Male grips the female with his antennae, The male then transfers sperm to the female. Eggs are sometimes laid directly into the water, but many species enclose them within a sac attached to female's body until they hatch.

Phylum Arthropoda Class Crustacea Subclass Copepodia Eggs hatch into a nauplius larvae The nauplius moults 5 or 6 times, before emerging as a "copepodid larva". After a further five moults, the copepod finally takes on the adult form. Egg to adult can take one week or one year depending on species

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Isopoda Mostly free-living marine e.g. Idotea sp Crawl rather than swim Terrestrial – pill bug Some parasitic (fish, shrimp and crab hosts) Biphasic molt Carapace – cephalic shield

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Isopoda - Elongated flat and somewhat arched bodies

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Isopoda Females are brooders After female moults males deposit sperm into the brood pouch Eggs pass from the oviduct into the pouch and are fertilized on the way Isopods hatch from the eggs as manca (adult like but last pair of walking legs are missing). Become juveniles 3 moults later

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Isopoda No free-swimming larval stage Endemism Dispersal limited to the crawling ability of the individual

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Isopoda Excirolana vancouverensis Consume 53% of body mass in 1 minute

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda c-shaped bodies flattened laterally Free living mostly marine and freshwater Swim or hop Do not have a carapace

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Females have a brood pouch Hatch as miniature adults Development varies with temperature For some, gender varies with temperature (cold = male, warm = female)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Amplexus – large males grasp onto females with their gnathopods and carry them for several days Females moult before they shed their eggs and are vulnerable to predation

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Females secrete a pheromone in her urine which triggers the guarding behaviour in males plus they lose the desire to eat them After her eggs are fertilized her exoskeleton hardens and the male is encouraged to leave

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Amphipods are difficult to identify, due to their small size, and the fact that they must be dissected. As a result, ecological studies and environmental surveys often lump all amphipods together Around 7,000 species of amphipods have so far been described

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Most planktonic species are symbionts with gelatinous animals sometime during their lifecycle.

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Few are parasitic The whale lice - these are dorso-ventrally flattened, and have large, strong claws, with which they attach themselves to baleen whales. They are the only parasitic crustaceans which cannot swim during any part of their lifecycle

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Amphipoda Caprellids Skeleton Shrimp. their body shape and colour help them blend with their surroundings and the gentle back and forth sway resembles substrate within the water current.

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda 15,000 species, half of these are crabs, ¼ are shrimp and the other ¼ are anomurans Most are marine but some are freshwater and a few are terrestrial

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Deca = ten, pod = foot Appendages 5 pairs on the thoracic segment, 1st usually a claw Three pairs, maxillipeds (mouth parts) Each abdomen segment has a pair of pleopods Tail fan telson and uropod

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda anatomy

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Shrimp vs Prawn Lamellar gill vs branched Two pairs of claws vs three Brood eggs before hatching vs doesn’t brood

Phylum Arthropoda Class Crustacea Subclass Malacostraca Shrimp Prawna

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Caridia Shrimps Adapted for swimming Bodies are laterally compressed Slender legs and well developed swimmerets (pleopods) Rostrum Compound eyes

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Coonstripe or Dock Shrimp (Pandalus danae)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Humpback or King Shrimp (Pandalus hypsinotus)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Smooth or Ocean Pink Shrimp (Pandalus jordani)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Pink Shrimp - Spiny (Pandalus borealis)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Prawn or Spot Shrimp (Pandalus platyceros)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Sidestripe or Giant Shrimp (Pandalopsis dispar)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Caridia Heptacarpus sp. Intertidal shrimps Transparent or a variety of colours Hide during the day, feed and are easily seen at night.

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Caridia Life cycle Spend 1st years as males then switch to females. Females brood their eggs (50,000 – 1 million)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Caridia Life cycle Eggs hatch nauplii larvae (yolk sac) metamorphosis into zoeae (feed on algae) Metamorphisis into myses (feed on algae and zooplankton Metamorphosis into young shrimp

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Caridia Amazing shrimps The pistol shrimp The mantis shrimp

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Differently tailed Have 5 pairs of periopods but 1 pair is internal and used to keep their gills clean If you see a crab with four legs then it is an anomuran.

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Squat Lobsters The body is usually flattened the abdomen is typically folded under itself the first periopods are greatly elongated and armed with long chelae (claws).

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Porcelain crab less than 15 mm (0.6 in) wide flattened bodies as an adaptation for living in rock crevices readily lose limbs when attacked use their large claws for maintaining territories They feed by using long setae (feathery hair on the mouthparts

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Heart crab Related to the Alaskan king crab the asymmetry of the crab's abdomen, which is thought to reflect the asymmetry of hermit crabs, which must fit into a spiral shell (pleopods are smaller on one side)

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Hermit crabs Live in gastropod shells usually. Spirally coiled soft abdodmen Pleopod assymetry tip of abdomen is adapted to clasp onto the columella of the shell.

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Hermit crabs vacancy chains: when a new, bigger shell becomes available, hermit crabs gather around it and form a queue from largest to smallest. When the largest crab moves into the new shell, the second biggest crab moves into the newly vacated shell and so on.

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Anomura Hermit crabs Symbiosis: with the sponge With anemones

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Brachyura True crabs Eg. Hemigrapsus sp reduced abdomen is entirely hidden under the thorax Telson not functional, uropods are absent

Phylum Arthropoda Class Crustacea Subclass Malacostraca Order Decapoda Infraorder Brachyura True crabs New research suggests that crabs not only suffer pain but that they retain a memory of it.

Pycnogonid – sea spider Body not divided into distinct regions Very slow moving Appendages at the head which are used to groom the opposite sex’s legs and are used by the males to carry fertilized eggs