1. Ms. Moore 2/15/13

2.  Phylum: Arthropoda  What is an Arthropod? Arthropods have a segmented body, a tough exoskeleton, and jointed appendages  Exoskeleton: tough external covering; like a suit of armor that supports and protects the body  Chitin: carbohydrate that makes up exoskeleton  Appendages: structures that extend from the body wall Antennae or legs

3.  1 st arthropods appeared in the sea more than 600 m.y.a.  Natural selection  fewer body segments and highly specialized appendages for feeding, movement, etc.  At least 75,000 species have been identified

4.  Feeding Include herbivores, carnivores, omnivores, bloodsuckers, filter feeders, scavengers, and parasites. Mouth parts range depending on diet

5.  Respiration of Terrestrial Arthropods Tracheal tubes: network of tubes that extend throughout the body Spiracles: small openings along the side of the body attached to tracheal tubes Book lungs: organs that have layers of respiratory tissue stacked like the pages of a book  Respiration of Aquatic Arthropods Featherlike gills

6.  Circulation Open circulatory system  Excretion Malpighian tubules: saclike organs that extract wastes from blood and add to feces Diffusion occurs in aquatic arthropods.  Response Well developed nervous system, brain, ventral nerve cord, and sense organs (compound eyes).

7.  Movement Use well-developed groups of muscles that are coordinated and controlled by nervous system Flex or extend muscles  Reproduction Terrestrial: internal fertilization; males have reproductive organ or sperm packet Aquatic: internal or external fertilization

8.  Exoskeleton does not grow with the animal. When they outgrow their exoskeletons, arthropods undergo periods of molting  Molting: arthropod sheds its entire exoskeleton and manufactures a larger one to take its place; controlled by the endocrine system (hormones)

9.  Arthropods are classified based on the number and structure of their body segments and appendages— particularly their mouthparts.  3 Groups: Crustaceans Spiders and relatives Insects and relatives

10.  Subphylum: Crustacea  Primarily aquatic  Crustaceans typically have two pairs of antennae, two or three body sections, and chewing mouthparts called mandibles.

11.  Cephalothorax: formed by fusion of the head with thorax  Thorax: lies just behind the head and houses internal organs  Abdomen: posterior part of the body  Carapace: part of exoskeleton that covers cephalothorax

12.  Mandible: mouthpart adapted for biting and grinding food  Gills are attached to appendages associated with cephalothorax  Decapods have five pairs of legs.  Chelipeds: first pair of legs; bear large claws  Swimmerets: flipper like appendages used for swimming  Final abdominal segment is fused = tail.

13.  P. 721 drawing

14.  Crustaceans include: Crabs Shrimps Lobsters Crayfishes Barnacles (sessile) How are these alike and different?

15.  Subphylum: Chelicerata  Chelicerates have mouthparts called chelicerae and two body sections, nearly all have four pair of walking legs.  Lack antennae found on most arthropods.  Cephalothorax: brain, eyes, mouth, legs  Abdomen: internal organs

16.  Chelicerates have two pairs of appendages attached near the mouth Chelicerae: contain fangs used to stab and paralyze prey Pedipalps: longer than chelicerae, modified to grab prey  Use book gills or book lungs  2 classes: Merostomata: horseshoe crabs Arachnida: spiders, mites, ticks, scorpions

17.  Horseshoe Crabs among oldest living arthropods, appeared more than 500 m.y.a. Heavily armored like crabs, but have anatomy closer to spiders  Spiders Largest group of arachnids No jaws—must liquefy food to swallow Chelicerae inject venom  paralyze prey  inject digestive enzymes  stomach breaks down Spinnerets: organs that contain silk glands P722 drawing

18.  Mites and Ticks Small arachnids Often parasitic Chelicerae and pedipalps specialized for digging into host’s tissues and sucking out blood/plant fluids Cephalothorax may stay in skin if pulled out  Scorpions Pedipalps enlarged into claws Abdomen carries a venomous stinger that can kill or paralyze prey Unlike spiders, scorpions chew prey using chelicerae

19.  Subphylum: Uniramia  Uniramians have jaws, one pair of antennae, and unbranched appendages.  Centipedes: Class: Chilopoida Segmented; each segment = one pair of legs, up to 100 pairs Carnivores: mouthparts with venomous claws  Millipedes: Class: Diplopoda Highly segmented; each segment = 2 pairs of legs Feed on dead and decaying plant material Timid and roll into ball for protection

20.  What is an Insect? Insects have a body divided into 3 parts— head, thorax, and abdomen. 3 pairs of legs are attached to thorax. Typical insect also has: pair of antennae, pair of compound eyes, two pairs of wings on thorax, and tracheal tubes.  The class, Insecta, contains more species than any other groups of animals.

23.  Use sense organs to detect external stimuli  Compound eyes: made of many lenses that detect changes in color and movement  Chemical receptors for taste on mouth, legs, and antennae  Sensory hairs on legs  Ears can be found in odd places (behind legs)

24.  Insects have 3 pair of appendages used as mouthparts: Mandibles used to saw and grind food (ant) Tubelike mouthpart use to suck nectar (moth) Spongelike mouthpart used to lap up food (fly)  Some produce saliva containing digestive enzymes to help break down food (nectar  honey)

25.  3 pairs of legs can be used for walking, jumping, or capturing and holding prey.  Flight—two pairs of wings made of chitin (also makes up exoskeleton)  Colonize a wide variety of habitats.

26.  Metamorphosis: process of changing shape and form Incomplete Metamorphosis: immature forms that undergo gradual change, look very much like adults Nymphs: immature forms; lack functional sex organs and other features like wings; molt several times and grow to acquire adult structures Complete Metamorphosis: hatch into larvae that look and act nothing like parents; also feed completely different Pupa: stage in which an insect changes from larva to adult; body completely remodeled inside and out  P729 stages and 3 examples of insects in each

27.  Negative effects Termites destroy wood structures Moths eat clothing and carpets Bees and wasps produce painful stings  Positive effects Pollination: 1/3 food we eat is pollinated by insects Products: silk, wax, honey

28.  Visual Cues Fireflies: light producing organ produces series of flashes  Chemical Signals Pheromones: specific chemical messengers that affect behavior or development of other individuals Fx: to signal alarm or alert; mating

29.  Society: group of closely related animals of the same species that work together for the benefit of the whole group (more than 7 million individuals)  Castes: specialized individuals/body form to perform particular tasks Reproductive females that lay eggs called queens Reproductive males Workers

30.  Each species has its own “language” of visual, touch, sound, and chemical signals  Bees use a form of dance for communication Round dance: food is nearby to hive Waggle dance: food is farther away from hive Also shows direction of food…

31.  Recap Recap  Give an example of 5 different insects and a specialized function/body part of each.

32.  Echino- means “spiny” and dermis means “skin”  Endoskeleton: internal skeleton formed from hardened plates of calcium carbonate  Echinoderms are characterized by: spiny skin an internal skeleton a water vascular system suction-cuplike structures called tube feet Most adults exhibit five-part radial symmetry. Only live in the sea

33.  Water vascular system: internal tube system; filled with fluid; carries out respiration, circulation, and movement  Madreporite: openings to outside from In sea stars, this connects to a ring canal that forms a circle around the mouth  five radial canals extend from this point  Tube foot: suction cup 100s attached to each radial canal

35.  Feeding Scrape algae from rocks Tube feet to capture/open prey Sea stars feed on mollusks  open shell and pours enzymes that partially digests mollusk  pulls in stomach and prey to mouth

36.  Respiration and Circulation Thin-walled tissue of tube feet Water-vascular system  Excretion Digestive waste  anus Nitrogenous waste  ammonia through skin and gills  Response Highly developed nervous system: nerve ring and radial nerves Scattered sensory cells

37.  Movement Tube feet Determined by endoskeleton  Reproduction External fertilization Larvae have bilateral symmetry

38.  Sea Urchins and Sand Dollars Large solid plates that form a box around internal organs Detritivores or grazers that eat algae  Brittle Stars Slender, flexible arms Can shed arms if under attack Filter feeders or detritivores

39.  Sea Cucumbers Look like moving pickles Travel in herds Detritus feeders suck up matter on sea floor  Sea Stars Carnivorous Incredible healing powers Each piece grows into new star

40.  Sea Lilies and Feather Stars Filter feeders Oldest class of echinoderms Attached to ocean bottom or atop coral reefs

41.  Marine habitats Population control Crown-of-Thorns: feeds on coral