PHYLUM ARTHROPOD A Arthropoda Characteristics account for 80% of all living animal species Arthropoda Characteristics means jointed foot eucoelom exoskeleton made of chitin cuticle of organism show a high degree of cephalization variety of segmented appendages around mouth serve as sensors and food handlers most have compound eyes & other light sensing structures cuticle inhibits growth causing organism to shed reason for molting body plan of repeated segments that attach to an appendage Arthropoda Characteristics open circulatory system Heart pumps circulatory fluid thru vessels that empty into spaces in the body nervous system is ladder-like with brain formed from fused ganglia respiratory & circulatory systems vary depending on species Evolutional & classification Evolved from a common ancestor Biologists are uncertain about the order in which subgroups of arthropods evolved & the exact relationships between the subgroups Similar characteristics of many modern subgroups may be the results of convergent evolution (process by which unrelated species become more similar as they adapt to the same kind of environment) EXAMPLE: TRILOBITES ~ancient & extinct Had many body segments & one pair of appendages on each segment Evolution & classification.continued Most living arthropod species have some segments that lack appendages and some segments that are fused into a larger structure called a tagma (tagmata, plural) Tagmata tend to be specialized for functions like feeding, locomotion & reproduction. REVIEW QUESTIONS 1. Identify the type & composition of an arthropods skeleton. 2. What is convergent evolution? 3. Explain how arthropods are highly cephalized. 4. What is a tagma? Plural form is ___. 5. What are they specialized for? PHYLUM ARTHROPODA Domain Eukarya Kingdom Animalia SUBPHYLUMEXAMPLES CLASSES (just common classes are listed) Broken down TrilobitomorphaTrilobites*Trilobita trilobites ChelicerataSpiders, Scorpions, Horseshoe crabs *Arachnida spiders & scorpions ticks & mites *Merostomata horseshoe crabs MyriapodaCentipedes, Millipedes*Chilopoda centipedes *Diplopoda millipedes HexapodaBees, Beetles, Crickets, Grasshoppers, Wasps, Butterflies, Moths. *Insecta insects CrustaceaBrine shrimp, Barnacles, Shrimp, Crabs, Lobsters *Malacostraca Lobsters, crabs, crayfish, shrimp, shrimplike krill *Maxillopoda barnacles * Brachiopoda brine shrimp DIVISIONS of Arthropoda Divided into 5 major subphyla Based on development in the structure of appendages, such as mouth parts 2 major types of mouth parts : 1.Mandibles (jawlike) Fig 1 2.Chelicerae (pincerlike) Fig Mandibulate Arthropod Characteristics: Mouthparts are mandibles - normally chewing sideways One or two pairs of antennae Various body region arrangements - cephalothorax & abdomen / head & trunk / head, thorax & abdomen Variable leg numbers Insects, crustaceans & myriapods mandibles Chelicerate Arthropod Characteristics: Pincher-like mouthparts - chelicerae - and pedipalps NO antennae Two body regions, usually - cephalothorax & abdomen Four pairs of legs Horseshoe crabs and arachnids are only living groups 5 subphyla 1.Trilobitomorpha 2.Chelicerata 3.Myriapoda 4.Hexapoda 5.Crustacea CHARACTERISTICMANDIBULATE ARTHROPODS CHELICERATE ARTHROPODS Mouthparts Antennae Body arrangement Leg # Examples Review Questions.. Add to ?s page 7. What major characteristic is used to divide arthropods into groups? 8. ID 2 major types of mouth parts, describe them & sketch a picture. 9. ID 3 groups of mandibulate arthropods. 10. ID 2 living groups of chelicerate arthropods. 11. Identify the 5 subphyla of phylum Arthropoda. Subphylum Trilobitomorpha Trilobites Most primitive of all arthropod groups EXTINCT Well-known fossil group of EXTINCT marine arthropods Subphylum Chelicerata Chelicerates including spiders, mites, scorpions, mites, and horseshoe crabs Lack antennae Typically have 6 pairs of appendages First pair of appendages, the chelicerae, are modified into pincers or fangs Classes: Arachnida: spiders, scorpions, mites, ticks Merostomata: horseshoe crabs CLASS ARACHNIDA Spiders, scorpions, mites, ticks Body divided into cephalothorax & abdomen Cephalothorax usually bears: *6 pairs of jointed appendages *1 pair of chelicerae *one pair of pedipalps (aid in holding/chewing) *4 pairs of walking legs pedipalps & chelicerae cephalothorax abdomen Mite vs Tick Body Regions Mite vs Tick Ticks are usually larger Ticks are ectoparasites (live on the outside of a host to survive) Mites are smaller Mites are more diverse & found in more habitats Mites are more free-ranging predators American dog tick female laying egg mass ( eggs!). American dog tick male Blacklegged (deer) tick female DEER TICKS can do this.. This photograph shows the bulls-eye rash that often manifests at the site of a tick bite when the Lyme disease bacterium is transmitted. REMOVING TICKSFYI Should you find a tick that has embedded its mouthparts in the skin, remove it as soon as possible using these tips from the Centers for Disease Control: Use fine-tipped tweezers or a notched tick extractor, and protect your fingers with a tissue, paper towel or latex gloves. Avoid removing ticks with bare hands. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure. Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. After removing the tick, disinfect the bite site and wash your hands with soap and water. Do not squeeze, crush or puncture the ticks body because its fluids may contain infectious organisms. Skin accidentally exposed to tick fluids can be disinfected with iodine scrub, rubbing alcohol or water containing detergents. Save the tick for identification in case you become ill. This may help your doctor make an accurate diagnosis. Place the tick in a sealable plastic bag and put it in your freezer. Dont use petroleum jelly, hot matches or other folk remedies as these may cause a tick to release additional saliva or gut contents, increasing chances of infection. While tick bites can cause problems, those problems are relatively rare. Dont stop enjoying nature, the great outdoors and your favorite warm-weather activities because youre fearful of tick bites. Just be sure to protect yourself first and do tick checks after being outdoors. DONT MASH THE TICK WHILE IT IS ATTACHED!! Ticks on a black iguana!!!!! Clover mites Twospotted spider mites Predatory mite pedipalp chelicera (fang) cephalothorax abdomen narrow waist Spider Anatomy Chelicerae are modified as fangs to inject venom Venom is produced in poison glands in cephalothorax & flow thru ducts to fangs Most have 8 simple eyes/each with single lens 3 pairs of spinnerets on tip of abdomen (made of microscopic tubules connected to silk glands) Respiratory system=book lungs (paired sacs in abdomen that are folded like pages of a book) *not all have these Trachea-system of tubes that carry air directly to tissues from openings in exoskeleton known as spiracles *not all spiders have these Some spiders have both book lungs & tracheae Malpighian tubules=main excretory organs that help conserve water in terrestrial environments Black widow with egg case Brown recluse Class Arachnida BROWN RECLUSE *has violin-shaped mark on dorsal surface of cephalothorax *aka violin spider *venom kills & digests the tissues surrounding the bite *necrosis=tissue death *bite is often not felt immediately *bite is rarely fatal but causes pain Neck of violin head of violin BLACK WIDOW *female has bright red or orange mark shaped like an hourglass on ventral surface of stomach *animals most at risk from BW bite: insects & male BW (females often eat the males after mating) *bite to humans is rarely fatal_pictures_slideshow/article.htm Wolf spider with egg caseSpitting spider Tarantula Orb-weaving spider Most poisonous spider in the world https://www.youtube.com/watch?v=pQYWBmk_V2g Brazilian Wandering Spider The Brazilian Wandering Spider Central/South America roam jungle floor at night Aka Banana spider When threatened they stand erect with their front legs drawn into the air and rock back and forth -> considerations for using venom to treat Erectile Dysfunction Camel Spider.. not poisonous to humans Aka sun scorpions but they try to avoid sunlight Among fastest of the arthropods They are not spiders and are not scorpions 2 families in North America: desert, grasslands, and beach dunes Not dangerous or venomous to humans-what can hurt you is the bacteria on their mouthparts Carnivores=use huge chelicerae to kill small rodents, spiders, insects, termites & small reptiles Camel spiderin desert 10 most poisonous spiders Scorpion differ from spiders because they . Have large, pincerlike pedipalps which they hold in a forward position Have segmented abdomen with a large stinger on the last segment Worlds Largest Spider Giant Huntsman Spider Considered this because of 12 leg span Southeast Asia Giant Huntsman Spider Discovered 2001 Confused w/tarantulas b/c they are big and hairy Differentiate them by crablike legs that allow side to side movement making them very fast and hard to catch Life span 2 years Females are very protective of young and can lay 200 eggs Relocate spider if found because spiders are important to ecological environment (food chain) Dont normally build webs b/c they actually hunt and attack their prey 2 nd largest spider Goliath Bird-eating Spider In tarantula family Males-3-6 years/females years Leg span of up to 12 and can weigh up to 60 ounces *can be classified as largest spider by MASS Has been witnessed eating a hummingbird Fairly harmless to humans diet primarily consists of insects& other invertebrates but has been known to kill & consume rodents, lizards, bats and even deadly venomous snakes Native to rain forest of South America Found burrowing in marshy, swampy areas Population is threated due to rain forest destruction https://www.youtube.com/watch?v=ri5BQdUR q9k Class Merostomata Live primarily in shallow ocean waters or on soft sandy or muddy bottoms Will come on shore for mating Commonly used as bait to fish for eels and whelk and in fertilizer Numbers are declining because of coastal habitat destruction & overharvesting along the East coast of North America Saving Horseshoe Crabs Review Questions # 3add to pg What is the most primitive of all arthropod groups? 12. What is the most primitive of all arthropod groups? 13. Describe the 1 st pair of appendages of chelicerates. 13. Describe the 1 st pair of appendages of chelicerates. 14. Identify the 6 pairs of appendages of an arachnid. 14. Identify the 6 pairs of appendages of an arachnid. 15. Which is largertick or mite? 15. Which is largertick or mite? 16. What is an ectoparasite? 16. What is an ectoparasite? 17. What body region contains the poison glands of spiders? 17. What body region contains the poison glands of spiders? 18. Why should you not squeeze a tick? 18. Why should you not squeeze a tick? 19. Differentiate the markings of a black widow and brown recluse. 19. Differentiate the markings of a black widow and brown recluse. 20. How do scorpions differ from spiders anatomically? 20. How do scorpions differ from spiders anatomically? 21. Why is the horseshoe crab population declinging? 21. Why is the horseshoe crab population declinging? Subphylum Myriapoda many legged arthropods all have one pair of antennae, a head region, and trunk with many pairs of legs use trachea Diplopoda - millipedes Chilopoda - centipedes Myriapods Millipede (Diplopoda) Two pair of legs per visible segment, attached under body. Centipede (Chilopoda) Pair of fangs under head, one pair legs per visible segment - attached to side of body. No fangs, no eyes, legs attached to side of body. [one pair of antennae, head & trunk regions, trunk with many pairs of legs] Scolopendra Galapagos Centipede Scolopendra galapagoensis Largest centipede 44-46cm Amazon Centipede Scolopendra gigantea Habitat distribution: Brazil, Ecuador, Peru, the Amazon River Basin countries and regions LEGS African Giant Black Millipede (Archispirostreptus gigas) Tanzania, Africa "Legs," one of the world's largest millipedes, these guys grow to be 10-12" long with 600 wiggly legs. Think of them like the world's largest roly-poly! They won't bite, pinch or sting but are very impressive! Great for all ages. SUBPHYLUM CRUSTACEA VERY DIVERSE GROUP VERY DIVERSE GROUP LOBSTERS, CRAYFISH, SHRIMP, KRILL, BARNACLES ARE MOST COMMON LOBSTERS, CRAYFISH, SHRIMP, KRILL, BARNACLES ARE MOST COMMON Characteristics: Characteristics: Most are aquatic (majority marine) two pairs of antennae a pair of mandibles a pair of compound eyes (usually on stalks) and two pair of maxillae on their headsfollowed by a pair of appendages on each body segment crustacean bodies usually are made up of head, thorax, and abdomen, although the segments composing these tagmata differ among different Classes) CLASS MALACOSTRACA EX: LOBSTERS, CRABS, SHRIMP, CRAYFISH EX: LOBSTERS, CRABS, SHRIMP, CRAYFISH LARGEST CLASS OF CRUSTACEA LARGEST CLASS OF CRUSTACEA DISPLAY GREATER DIVERSITY OF BODY FORMS THAN ANY OTHER CLASS OF ORGANISMS DISPLAY GREATER DIVERSITY OF BODY FORMS THAN ANY OTHER CLASS OF ORGANISMS ABUNDANT IN MARINE ECOSYSTEMS ABUNDANT IN MARINE ECOSYSTEMS VIRTUALLY EVERY FEEDING HABIT IS EXHIBITED BY SOME MEMBER OF THIS CLASS FROM PREDATOR TO PARASITE TO FILTER FEEDER (RARE) VIRTUALLY EVERY FEEDING HABIT IS EXHIBITED BY SOME MEMBER OF THIS CLASS FROM PREDATOR TO PARASITE TO FILTER FEEDER (RARE) JAPANESE SPIDER CRAB 12 FEET SPAN IN LEGS 41 lbsom/watch?v=rh5W0Sy rWyg Class Maxillopoda BARNACLES *sessile *marine shallow and tidal waters *feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structuret-whttp://www.youtube.com/watch?v=25F7xMVN t-w BARNACLE FEEDING Class Brachiopoda Brine shrimp Very primitive Can live in water with high salt concentration (salinity) Some species are on endangered species list Review Questions Set Give a general body description of members of subphylum Myriapoda. 22. Give a general body description of members of subphylum Myriapoda. 23. Id the most common examples of subphylum Crustacea. 23. Id the most common examples of subphylum Crustacea. 24. Give 5 body characteristics of crustaceans. 24. Give 5 body characteristics of crustaceans. 25. What is the largest class of Crustacea? 25. What is the largest class of Crustacea? 26. What class has the most diverse body form of all classes of animals? 26. What class has the most diverse body form of all classes of animals? 27. Describe the feeding method of barnacles. 27. Describe the feeding method of barnacles. 28. What is a unique characteristic of brachiopods? 28. What is a unique characteristic of brachiopods?