Arthropods

1. Arthropods Jenene Lewis Jessica Jones Rachel Slack

2. ArthropodsBasic Info Easily the most successful lineage of eukaryotes. They appear in fossil records over 520 million years ago in both marine and terrestrial environment. There are estimated tens of millions that have still not been discovered while over a million have been described. They are distinguished by segmented bodies and jointed exoskeleton. The body is separated by a head and trunk regions. The trunk region has three common names either the abdomen, the thorax or the tail. Metamorphosis is common in arthropods. Appendages have many functions: sensing their surroundings, exchanging gases, feeding, or locomotion. Most have compound eyes and antennae.

3. ArthropodsHabitat • Arthropods are found in almost all of the habitats that cover the Earth's surface.  • Many crustaceans live in the sea at depths exceeding 4,000 meters, while the insect collembolans and jumping spiders have been found on Mount Everest at heights exceeding 6,700 meters.  Collembolans and the orbatid mites are among the permanent inhabitants of Antarctica.  • Brine shrimp are found in some saltwater lakes, and beetles, mites, and various crustaceans have been taken from hot springs.  • Minute crustaceans inhabit underground waters in many parts of the world, and deserts support a large arthropod fauna, especially insects and arachnids. • Found in virtually all habitat types, if numbers of species and diversity is used to measure success, then this group is the most successful of all the terrestrial invaders. • Small, terrestrial forms must occupy humid microhabitats to avoid drying out. Because the power of muscle fibers is proportional to their cross-sectional area, large arthropods are relatively weaker. • Large forms are too heavy and weak to move quickly and also have trouble breathing, since gas exchange is mostly by simple diffusion. Therefore, size and habitat are somewhat restricted among terrestrial forms.

4. ArthropodsEcology and Human Interaction • It is almost impossible to generalize about the ecology and life history of arthropods; they are simply too diverse. • Arthropods first appeared in the sea; trilobites (famous groups of extinct organisms) were all marine. • Their fossils are instantly recognizable and often strikingly beautiful. In fact, prehistoric people liked them as much as we do. • Arthropods represent over 80% of the Animal Kingdom and probably at least half of all living organisms. Trilobite

8. Myriapods • Basic Info Millipedes and Centipedes Over 11,600 species described to date. They commonly have simple bodies. Body broken up into head region and a long trunk with short segments, each segment has a pair of legs on each segment. Use mouthparts the can bite and chew. Have poison containing fangs used to hunt insects. Most myriapods walk or run on their legs, some burrow. Sexes are separate, and fertilization is internal.

9. Myriapods Habitat Most myriapods are nocturnal and prefer moist habitats and are often found in soil and leaf litter, under rocks and logs or under the bark of trees. Many species have specialized glands that produce a foul tasting liquid that they secrete as a defense against predators.

10. MyriapodsEcology and Human Interaction • Generalist predators, feeding mainly on small subsoil arthropods • Most millipedes eat decaying leaves and other dead plant matter, moisturizing the food with secretions and then scraping it in with the jaws. • Myriapods were used back in the early war times. Before there was medicine the doctors would put leeches on the patient and allow them to such the blood from the patient.  • Large centipedes can inject enough poison to debilitate a human. • Millipedes and Centipedes chew dead wood.  Humans continue to cut down the forests therefore taking the homes these creatures live in. • Can be a slight garden pest, especially in greenhouses where they can cause severe damage to emergent seedlings. Signs of millipede damage include the stripping of the outer layers of a young plant stem and irregular damage to leaves and plant apices

11. Chelicerata • Basic Info • Spiders, Ticks, Mites, Horseshoe • Crabs, Daddy Longlegs, and Scorpions • 70,000 species described to date. • Body consists of anterior and • posterior regions. • Anterior does not have antennae, • like most arthropods, but eyes. • Known for an appendage near the • mouth called chelicerae. This is used • for feeding, defense, movement, or • sensory reception, depending on the • species. • Spiders, scorpions, and daddy long-legs captures and sting their prey. • Most spiders are sit-and-wait predators. • Chelicerates move with the aid of muscles attached to an exoskelton • Fertilization is internal in most groups.

12. Chelicerata • Spider’s Habitat • Most spiders live in very specific habitats, in this way they divide up the world • between them and avoid undue competition. Their environmental choices are made • depending on their ability to withstand such abiotic variables as temperature, both the • average as well as the seasonal maximums and minimums, wind presence, moisture, • humidity and light intensity. It is also effected by abiotic considerations such as • vegetation type, competitors and predators. • The amount of space a spider needs to live in is small, especially for web building spiders, • they can go a long time without food and expend little energy waiting fro their prey. Spiders that • hunt out their prey obviously use more energy but even these can live for weeks without eating. • This, and the small size of most spiders means their can be a great diversity of spiders in every • habitat with different species occupying different niches only a few centimetres apart. • Scientists studying the distribution of spiders within a given habitat have found • that vertical distribution up a tree trunk have found that microclimate, bark structure • as well as height are important features controlling which spiders live where. In • another study scientists found that two spiders, Pardosa • pullata and Pirata piraticus both live in sphagnum bogs, however P. • pullata lives near the surface and P. piraticus down inside the moss. • The temperature, which varies near the surface is much more • stable lower down.

13. Chelicerata • Ticks Habitat • The tick habitat must satisfy two essential requirements for tick survival and persistence. • These are the provision of sufficiently high humidity for the ticks to maintain water balance and • of a mix of animal species to act as hosts for the three tick instars, larva, nymph and adult. Ticks • are vulnerable to desiccation during intermittent periods of host seeking (questing) and in exposed areas such activity may only last a few weeks, whereas in sheltered environments questing can continue for several months. Ticks are also vulnerable to desiccation during the long development phase, when they are located on or near the soil surface. Here they transform over a period of months into the next instars, or in the case of adult females, lay eggs. • In both questing and developing phases ticks can obtain water from subsaturated air by secreting and then re-ingesting hygroscopic fluid that is produced by the salivary glands. This activity enables ticks to maintain a stable water balance as long as the relative humidity of their microclimate does not fall below 80% for any length of time. These ticks can therefore only survive in areas where a good cover of vegetation and a mat of decaying vegetation. Relative humidity at the base of the vegetation remains above 80% throughout the driest times of the year, usually the summer. However, such habitats can also be too wet ticks will not survive in areas that are flooded for extended periods in winter. • The habitat must also contain a suitable concentration and variety of hosts for each parasitic stage (larva, nymph and adult females) of the ticks. The adults will only feed successfully on larger animals such as deer, sheep, cows and dogs. The immature stages can parasitize almost any warm-bloodied animal (as well as some reptiles), but nymphs are less successful on small mammals than are larvae. These requirements mean that ticks are mainly located in deciduous woodland containing both small and large mammals, but they can also be found in coniferous forest, as long as there is sufficient vegetation litter on the ground and the microclimate is moist. In open habitats such as meadows and moorland the main source of blood meals for all stages is usually livestock such as sheep and cows. Ticks also occur in domestic settings, but they are seldom found in well-maintained lawns where the grass is cut frequently to keep it short and the edges are kept trim. Foliage and litter can give shelter to both the ticks and to small mammals which act as hosts for immature ticks. 

14. ChelicerataHorseshoe Crabs Habitat • There are only four species of horseshoe crabs in the world. Three live in Asia in the Indo-Pacific waters. Only one lives in North America- the Limulus polyphemus. It lives along the Atlantic coast from Maine to the Gulf of Mexico. Horseshoe crabs can live in a variety of conditions. They can live in shallow water along the shore of a tidewater bay or inlet, or they can live offshore on the continental shelf in water seventy-five feet deep. They can live in sea water or water in an estuary that is only one fourth as salty. They can survive in a wide range of water temperatures. The only thing is that when the water starts to get cold and the water temperature goes below 55 degrees F., horseshoe crabs bury down in the mud and sand. They stay there until the water warms up again.

15. ChelicerataDaddy Longlegs Habitat • Eggs are deposited individually deep into the soil and they hatch the following spring. During the fall, large numbers of harvestmen often are seen clustered together. Because groups are observed at harvest time, they were named accordingly, harvestmen. Adults usually do not survive in northern climates where freezing occurs. Daddy-long-legs usually are inactive and hidden during the day, then at sunset, they begin to wander about searching for food. Many Opiliones feed on live insects, especially aphids. Other species feed on dead insects or plant juices. • Harvestmen commonly live among plants or on tree trunk. Daddy-long-legs are rarely encountered in living areas of a building, but are more often found in crawl spaces, basements, and outbuildings. They often rest on buildings—on the walls, under the eaves, or in windowsills.

16. ChelicerataScorpions Habitat • Though most prolific and diverse in warm habitat, scorpions have adapted to a wide range of environments, including plains and savannahs, deciduous forests, mountainous pine forests, rain forests and caves. • Scorpions have been found at elevations of over 12,000 feet in the Andes Mountains in South America and in the Himalayas of Asia, as well as the Alps. • In snowy areas, they hibernate during the cold months of the year. In drought areas they may aestivate (pass the summer in a dormant or torpid state). • About 90 species are found in the U.S. All but four of these naturally occur west of the Mississippi River. • Scorpions are most common in southern Arizona and in parts of Texas and central Oklahoma.

17. Chelicerata Ecology and Human Interaction Most of the marine chelicerates, including all of the eurypterids, are now extinct. Most spiders have 8 eyes. The first two have perfect vision that allows the spider to see right in front of it. The other 6 eyes are used for perfect peripheral vision that can allow them to see the smallest of prey move centimeters at a time. This is how they can catch their prey so easily. The predatory habits of these critters helps to control insect populations in many parts of the world. Some arachnid chelicerates are parasites, such as ticks and mites. They live upon the bodies of other animals and feed on the blood, skin, or hair. Some of these carry diseases, which they pass on to the host when they feed. Still other chelicerates are tiny organisms which feed on detritus, the bits of decaying matter that accumulate on and below the ground. The first terrestrial chelicerates are believed to have been detritus feeders. The young must fend for themselves from the time they hatch. Survival is then dependant on the fact that large numbers of eggs are produced at a time, and it is likely that at least a few will survive. Chelicerata: Spiders Ticks Mites Horseshoe Crabs Daddy Longlegs Scorpions

18. Insecta Basic Info 925,000 species described to date. Have three body regions Head: contains three mouthparts, antennae, and compound eyes. Thorax: contains three pairs of legs and most have one or two pairs of wings on the side. Abdomen With the large amount of insects they are able to feed in every conceivable manner and on almost every type of food source available on land. Insects use their legs to walk, run, or swim, or they use wings to fly. Sexes are separate. Most females lay eggs, but in a few species eggs are retained until hatching.

19. InsectaHabitat • The success of insects as a group is reflected by the diversity of habitats they live in, which includes terrestrial (desert, forest, grassland, rainforest), freshwater (ponds, lakes, streams, wetlands) and marine.

20. InsectaEcology and Human Interaction • Insect behavior is controlled largely by the central nervous system. As a result, insects’ reactions to the world around them, and to other members of their species, usually follow fixed patterns. For example, one of these patterns makes moths fly to bright lights. • Even though bright lights are often hot, moths cannot override their instinct and choose to fly away. Despite this built-in programming, insects behave in complex ways. • Butterflies in particular have evolved by their different colors and patterns. In areas with bright vibrant colors one will find butterflies with the same bright colors so that they can be camouflaged for safety and visa versa if the habitat is darker in color and light. • During their daily lives, they successfully deal with hundreds of different situations, including defending themselves against attack, tracking down food, and finding a mate. • Help with the fertilization of plants with their pollen. Thus, allowing gardens and other plant life to grow abundantly.

22. Crustaceans Basic Info • Shrimp, Lobster, Crabs, Barnacles, Isopods, and Copepods • 67,000 species are described to date. • Important grazers and predators in shallow-water. • Have a cephalothorax which is a combination of the head and the thorax. • They have a carapace which is a platelike section of their exoskeleton that covers and protects the cephalotorax. • Crustaceans use every type of feeding strategy known. • Typically have mouthparts called mandibles that are used to bite or chew. • Herbivores or detritivores, but depend on algae for food. • Crustaceans limbs are highly diverse. • Each individual is male or females, and sexual reproduction is normal.

23. CrustaceansHabitat • Crustaceans vary in the habitat in which they live. • Some live in the ocean, some in fresh water and some on the land. • Many crustaceans are nocturnal and spend the day hidden in a burrow, buried in the sand, or resting in a crevice vary in habitat in which they live, some live

24. CrustaceansEcology and Human Interaction • Most crustaceans are also marine, but one crustacean group has successfully invaded the land, the Isopoda, a.k.a. "pillbugs" or "roly-polies." • The vast majority of living arthropods belong to groups that are specialized for a land-dwelling existence. One of them, the African tsetse fly, is shown here as a reminder of how successful some arthropods have been at the expense of other organisms. • Crustaceans are modified for a wide variety of habitats and ways of life. They are important in the food chain, partly because so many of them eat small plants and animals. Many strain small particles of food from the water, but the larger crustaceans, such as shrimp and crabs, are often omnivores, scavengers, or predators. Several species are also parasites. Crustaceans are consumed by many animals, including humans, and are rich in protein. • We eat them for food. Known as “sea food” which can be prepared so many different ways such as: • Broiled, baked, fried, sautéed, stuffed, steamed, deviled, etc.

25. 1. What habitats do myriapods prefer? a. moist b. dry c. in crawl spaces under buildings

26. Answer: A

27. 2.  What is one specification that a spider requires for its habitat? a. it has to avoid undue competition b. the area has to be small c. the wind presence has to be high

28. Answer: A

29. 3. What two specifications do ticks require for survival in their habitat? a. these are the provision of sufficiently low humidity for the ticks to maintain water balance and a mix of animal species to act as hosts b. these are the provision of sufficiently high humidity for the ticks to maintain water balance and of a mix of animal species to act as hosts c. these are the provision of sufficiently no humidity for the ticks to maintain water balance and of a mix of animal species to act as hosts

30. Answer: B

31. 4. What are two types of environments have scorpions adapted to for their habitat? a. plains and savannahs b. rivers and streams c. islands and deserts

32. Answer: A

33. 5. The success of survival of insects, as a group, is based on the diversity of their habit, what is one area of environment that they make their home? a. beach     b. mountains     c. freshwater

34. Answer: C

35. 6. What is an example of a myriapod?  a. Spider b. Swallowtail butterfly c. Centipede d. Deep-sea Lobster

36. Answer: C

37. 7. The four groups: (Myriapods, Chelicerata, Insecta, and Crustaceans) are all part of what major group?       a. Platyhelminthes       b. Arthropods       c. Annelida       d. Mollusca

38. Answer: B

39. 8. How many regions do the Chelicerata group have?      a. 5      b. 3      c. 9      d. 2

40. Answer: D

41. 9. What is the function of the arthropod exoskeleton?     a.  presence of an exoskeleton gives help to the fossil record     b. It has no distinct function     c. provides protection to the arthropods inner organs     d. It makes growth by molting possible

42. Answer: C

43. 10. Which phylum is distinguished by having segments organized by distinct regions?       a. Arthropods       b. Mollusca       c. Arthropoda       d. Nematoda

44. Answer: A

45. 11. Which of the following is not a commonly known name for the trunk region of a typical arthropod? a. tail b. thorax c. appendage d. abdomen

46. Answer: C

47. 12. Which of the following is a way that myriapods use to hunt insects? a. kicking them with their legs b. running over them c. hiding and then attacking d. using their fangs that contain poison

48. Answer: D

49. 13. Which of the following does NOT belong in the group Chelicerata? a. Spiders b. Millipedes c. Scorpions d. Daddy longlegs

50. Answer: B