Kingdom Animalia Phylum Arthropoda Arthropods Kingdom Animalia Phylum Arthropoda

Phylum arthropoda Largest group of animals with 750,000 species Basic body plan: segmented bodies Tough exoskeleton jointed appendages

exoskeleton tough external covering like a suit of armor protects and supports the body made from chitin exoskeletons of land-dwelling, species have a waxy covering that helps prevent the loss of body water

Appendages All have jointed appendages Appendage- structure, such as a leg or antenna, that extends from the body wall.

Evolution of arthropods The have been around for 600 million years in the ocean. Today arthropods live everywhere! Land, sea and air!

Feeding Some are: herbivores carnivores omnivores bloodsuckers (parasites) filter feeders detritivores

Respiration Most terrestrial arthropods breathe through a network of branching tracheal tubes that extend throughout the body. Air enters and leaves the tracheal tubes through spiracles which are small openings located along the side of the body.

Respiration continued… Some terrestrial arthropods, like spiders, respire using book lungs. Book lungs are organs that have layers of respiratory tissue stacked like the pages of a book. Most aquatic arthropods, such as lobsters and crabs, respire through featherlike gills. The horseshoe crabs, however, respire through organs called book gills.

excretion Malpighian tubules are saclike organs that extract wastes from the blood and then add them to feces, or digestive wastes, that move through the gut.

Response have a well-developed nervous system. All have a brain. have sophisticated sense organs, such as compound eyes Compound eyes may have more than 2000 separate lenses and can detect color and motion very well. and taste receptors

Movement Move using well-developed groups of muscles that are coordinated and controlled by the nervous system. Muscles generate force by contracting and then pulling on the exoskeleton.

Reproduction Terrestrial - internal fertilization. Aquatic - internal or external fertilization. Some males have a reproductive organ that places sperm inside females. In others, the males deposit a sperm packet that is picked up by the females.

Grow and develop When they outgrow their exoskeletons, arthropods undergo periods of molting. During molting, an arthropod sheds its entire exoskeleton and manufactures a larger one to take its place. This process is dangerous to the animal because it is vulnerable to predators while its shell is soft.

Groups of Arthropods Crustaceans Spiders (and their relatives) Insects (and their relatives)

How are they Classified? classified based on the number and structure of their body segments appendages— and mouthparts.

Crustaceans Crayfishes Barnacles Pill bugs Class (subphylum) Crustacea primarily aquatic Examples Crabs shrimps lobsters Crayfishes Barnacles Pill bugs

Crustaceans typically have two pairs of antennae two or three body segments and chewing mouthparts called mandibles.

crustaceans The cephalothorax is formed by fusion of the head with the thorax. thorax lies just behind the head and houses most of the internal organs. The abdomen is the posterior part of the body.

Crustaceans The carapace is the part of the exoskeleton that covers the cephalothorax. A mandible is a mouthpart adapted for biting and grinding food.

Decapods (10 legs) Largest group of crustaceans first pair of legs are called chelipeds. Chelipeds: large claws that are modified to catch, pick up, crush, and cut food.

Crustaceans Along the abdomen are several pairs of swimmerets. Swimmerets: flipperlike appendages used for swimming. Tail also helps them swim, backwards

Barnacles Sessile attach to rocks and marine animals Because of their outer shell-like coverings, barnacles were once classified as mollusks.

Spiders (and their relatives) Kingdom Animalia Phylum Arthropoda Subphylum Chelicerata Members include: Horseshoe Crab Spiders Tick Scorpion

Chelicerates have: mouthparts called chelicerae two body sections (cephalothorax and abdomen four pairs of walking legs (some 5)

Chelicerates two pairs of appendages adapted as mouthparts. chelicerae contain fangs and are used to stab and paralyze prey. pedipalps are longer than the chelicerae and are usually modified to grab prey

Chelicerates are divided into two main classes: Class Merostomata includes horseshoe crabs Class Arachnida includes spiders, mites, ticks, and scorpions.

Horseshoe crab oldest living arthropods (500 million years ago) not crabs at all They are heavily armor-plated, like crabs, but have an anatomy closer to that of spiders. have chelicerae five pairs of walking legs Long tail used for movement.

Spider Feeding Some spin webs of a strong, flexible protein called silk, which they use to catch flying prey.

Spider feeding Others, like the tarantula stalk and then pounce on their prey.

spiders do not have jaws for chewing must liquefy food to swallow it. uses fanglike chelicerae to inject paralyzing venom into it. then spider injects digestive enzymes into the wounds. These enzymes break down the prey's tissues the spider sucks the tissues in the form of a liquid

Spiders All spiders produce silk Spinnerets- are organs that contain silk glands. Use it for: webs cocoons for eggs wrappings for prey

Mites and Ticks Small Often parasitic Ticks can transmit bacteria that cause serious diseases, such as Rocky Mountain spotted fever and Lyme disease.

Mites and Ticks Includes: Wood ticks Deer Ticks Head lice Bed Bugs Dust Mites

Scorpions Live in warm areas Pedipalps enlarged into claws. The long, segmented abdomen of a scorpion carries a venomous stinger that can kill or paralyze prey.

Insects (and their relatives) Kingdom Animalia Phylum Arthropoda Subphylum Uniramia Characteristics of Uniramians have jaws one pair of antennae unbranched appendages

Class Chilopoda – the centipedes Can have 100 pairs of legs, or more carnivores with venomous mouthparts Liveunder rocks or in the soil

Class Diploda – Millipedes two pairs of legs/segment live under rocks and in decaying logs. Eat dead and decaying plant material. When disturbed, roll up into a ball. defend themselves by secreting unpleasant or toxic chemicals.

Percentage of animal species

Class Insecta body divided into three parts— Head thorax abdomen. Three pairs of legs are attached to the thorax. 1 pair of antennae 1 pair of compound eyes two pairs of wings on the thorax

Compound eyes Multiple lenses make up one image Image is less detailed than humans BUT BETTER AT DETECTING MOVEMENT

Insect senses have chemical receptors for taste and smell on their mouthparts and also on their antennae and legs. Many insects also have well-developed ears that hear sounds far above the human range. Located behind the legs in grasshoppers 

Insect feeding have three pairs of appendages that are used as mouthparts, including a pair of mandibles. These mouthparts can take on a variety of shapes

Many insects can fly!  flight has allowed insects to disperse long distances and to colonize a wide variety of habitats.

Metamorphosis:the process of changing shape and form. Insects undergo either incomplete metamorphosis or complete metamorphosis.

Metamorphosis continued Incomplete metamorphosis: type of insect development characterized by a similar appearance throughout all stages of the life cycle.

Metamorphosis continued Complete metamorphosis: type of insect development in which the larva look and act nothing like their parents.

Societies Ants, bees, termites, and some of their relatives form complex associations called societies. A society is a group of closely related animals of the same species that work together for the benefit of the whole group.

Castes Within an insect society, individuals may be specialized to perform particular tasks, or roles. These are performed by groups of individuals called castes