- · Mostly terrestrial or marine
- · Lack antennae
- · Body consists of cephalothorax and abdomen (most)
- · Six pairs of appendages:
- § 1 pair chelicerae – claw-like feeding appendages
- § 1 pair pedipalps – sensory structures
- § 4 pairs walking legs
What are some examples of Chelicerata?
(horseshoe crabs, spiders, scorpions, harvestmen, mites, ticks)
one pair of legs per segment; carnivorous
two pairs of legs per segment; herbivorous
- · Terrestrial
- · Body divided into head and trunk
- · Head with mandibles and antennae ( 1 pair )Body with many legs
exhibit 4 life stages [egg à larva à pupa à adult]
exhibit 3 life stages [egg à nymph à adult]
- · Dominant terrestrial arthropods
- · Body has 3 sections: head, thorax and abdomen
- · Antennae (1 pair)
- · Mouthparts – mandibles modified for chewing , sucking, sponging, or lapping
- · Three pairs of legs on thorax
- · Two pairs of wings ( most )
- · Breath via tracheae – unique to insects; open to outside via spiracles
- · Exoskeleton periodically molted.
What are some examples of Hexapoda?
( dragonflies, grasshoppers, true bugs, mantophasma, beetle, flies, bees, butterflies)
- · Mostly marine and freshwater
- · Body of most with 2 sections: cephalothorax and abdomen
- · Appendages on thorax and abdomen
- · Two pairs of antennae
- · Mandibles as mouthparts
- · Dioecious ( most)
- · Nauplius larva
- -krill- main food item of baleen whales
What are some example of Crustacea?
(crabs, crayfish and lobsters, shrimps, krill, copepods, isopods, barnacles)
What are the four major arthropod groups?
earliest authropods to evolve
Diversity and success related to body plan are?
segmented bodies, hard exoskeleton and jointed appendages.
Arthropoda (“jointed feet”) characteristics?
- · Jointed appendages
- · Coelomate (reduced as a hemocoel)
- · Segmented body
- · Exoskeleton composed of protein and chitin (provides protection and waterproofing; must be molted)
- · Muscles attached to exoskeleton
- · Well-developed sensory organs
- · Open circulatory system – hemolymph percolates through hemocoel.
Parasitic nematodes of humans?
pinworms, hookworms, Filarial worms – cause elephantiasis, trichinella spiralis – causes trichinosis
Parasitic nematodes of plants feed on roots?
inhibit plant growth, reduce yields and distort root structure.
Nematoda (roundworms) charateristics?
- · Ubiquitous
- · Free-living or parasitic
- · Unsegmented body; tapered at both ends
- · Pseudocoelomate
- · Thick cuticle (shed 4 times)
- · Complete digestive tract
- · Longitudinal muscles
- · Dioecious ( Female are larger than male)
What are the Ecdysozoans?
- Nematoda (roundworms)
- Arthropoda (“jointed feet”)
- · Head surrounded by grasping tentacles, usually with suckers
- · Shell external, internal or lacking
- · Mouth with or without radula
- · Only mollusks with closed circulatory system
- · Locomotion by jet propulsion using siphon (modified foot)
- · Predators
Gastropoda (aposmatic coloration) characteristics?
- · Marine, freshwater, terrestrial
- · Head present
- · Coiled shell (most)
- · Many are monoecious
- · Foot used for locomotion
- · Have radula
- · Marine and freshwater
- · Hinged, laterally flattened shell
- · Mantle forms incurrent and excurrent siphons
- · Reduced head
- · No radula
- · Filter feeders
What is an example of Cephalopoda?
squid, octopus, cuttlefish, nautilus
What is an example of Gastropoda (aposmatic coloration)?
What is an example of Bivalvia?
Polyplacophora (chitons) characteristics?
- · Marine
- · Shell with 8 plates
- · Foot used for locomotion
- · Radula used to scrape algae from rocks
What are four classes of mollusks?
- Polyplacophora (chitons)
- Gastropoda (aposmatic coloration)
- · Coelomate (reduced)
- · Mostly marine
- · Most have an open circulatory system and a hard shell of calcium carbonate
- · Body has 3 main parts: foot, visceral mass and mantle
- · Most are dioecious
- · Trochophore larval stage in marine mollusks