Download
1 / 103
1.03k likes | 1.04k Views
`. PHYLUM ARTHROPODA. 1. Characteristics of arthropods 3/4 of all animal species belong to this phylum. Arthropods are segmented animals. The name means “____________”. 2. Arthropods have an _____________ which provides support and protection.
E N D
` PHYLUM ARTHROPODA
1. Characteristics of arthropods • 3/4 of all animal species belong to this phylum. • Arthropods are segmented animals. The name means “____________”.
2. Arthropods have an _____________ which provides support and protection.
3. The exoskeleton has three layers. The waxy outer layer is made of proteins and ____________. This makes it water repellent and helps keep them from drying out.
4. The middle layer is composed of protein and __________ and sometimes calcium carbonate. It also provides support and protection.
5. The inner layer also contains protein and chitin but is flexible at the joints allowing movement. __________ are attached to the inner layer to help them move.
6. Most have a high degree of cephalization with sensory structures and complex mouths. Many have segmented antennae, compound ____ (eyes composed of many light detectors, each with its own lens).
7. All arthropods have an ___________ circulatory systems. • Because the skeleton is on the outside it must be shed in order for the arthropod to grow. This process is called molting.
8. An arthropod molts many times in its life becoming ______ with each molting. In between molts the tissues swell until they put a lot of pressure on the exoskeleton.
9. A hormone is then released that induces molting. In response to the hormone certain cells secrete enzymes that digest the flexible inner layer of the __________.
10. At the same time the epidermis begins to make a new exoskeleton using a lot of the digested material. Eventually the outer layer of the old exoskeleton loosens, breaks along specific lines, and is _______________.
11. The new exoskeleton, which is flexible at first stretches to fit the enlarged animal. It takes a few days for the new exoskeleton to harden. The animal is very vulnerable at this time and usually ____________.
12. Arthropods are divided into _____ subphyla on the basis of differences in their mouth parts and other appendages as well as how they develop.
The 4 subphyla are • Trilobita • Crustace • Chelicerata • Uniramia
13. The trilobites are all _____. They had similar paired appendages on each of the body segments.
14. Crustacea includes shrimp, lobsters, crabs, crayfish, barnacles, isopods, copepods, and water fleas. They have branched antennae and a pair of chewing mouthparts called ________.
15. Chelicerata includes spiders, ticks, scorpions, mites, sea spiders, and horseshoe crabs. • They have ____ antennae. • They have pincer-like mouthparts called chelicera.
16. Unirania includes centipedes and millipedes and insects. They have antennae but their appendages are unbranched. They are the only group that is believed to have evolved on land.
17. Contains about 40,000 species. • Crustaceans are the only arthropods that have ___ pairs of appendages on their head that act as feelers.
18. Each segment has usually has a pair of branched appendages. Some have over 60 segments but they usually have 16 – 20 which are fused into several _____. A tagmata is several segments that have fused to perform a specific function.
19. The exoskeletons of many aquatic crustaceans have a lot of calcium carbonate which makes them very hard. • The crustacean larva is called a __________________ larva. Six appendages, one eye.
20. Most crustaceans are very small. Copepods are only about 1 millimeter in length but may be the most abundant species on earth.
21. Copepods make up most of the plankton in the ocean where they are an important part of the ocean food chain.
22. Barnacles are ________ crustacean that attach themselves to rocks, ships, piers, whales, etc.
23. Sow bugs and pill bugs are terrestrial members of a group of crustaceans called _____. They have to live in moist environments to keep from drying out. They usually live under rocks and in leaf litter.
24. The Crayfish Structurally they are very similar tolobsters. Both are called _____ (ten feet). Shrimps and crabs are also decapods.
25. The body is divided into 2 major sections. The cephalothorax and the abdomen. • The cephalothorax consists of 2 tagmata, the head which has 5 segments and the thorax which has 8.
26. They have a large covering called a _____ that covers most of the body. The abdomen is divided into 7 segments. The last one is called the _____ and looks like a paddle. It helps them swim backwards quickly.
27. They have antennules that serve as feelers which respond to touch and taste. • They chew their food with the mandibles and manipulate it with two pairs of maxillae and three pairs of maxillipeds.
28. The most anterior appendages on the thorax are the ______. They are used for defense and to capture food. • The swimmerets are appendages attached to the 5 abdominal segments. They are used in reproduction.
29. Food passes through the esophagus to the stomach where teeth made of chitin and calcium carbonate grind the food into a paste. The paste is mixed with enzymes secreted by the digestive gland.
30. It then enters the intestine and digestive gland for digestion and absorption. What does not get digested is removed through the anus. • Crayfish use ____ for respiration.
31. They have an _____ circulatory system with a heart. • Because they live in fresh water they are constantly receiving water into the body. This excess water is removed by organs called ______ glands.
32. The fluid collected by the green glands is removed from the body through a pore at the base of the antennae. • The crayfish ____ consists of a pair of ganglia above the esophagus that gets signals from the eyes, antennules, and antennae.
33. Crayfish sense vibrations and chemicals in the water with thousands of sensory hairs that are distributed over the body. • The compound eyes are set on 2 short moveable stalks. Each eye has more than 2,000 light sensitive units with their own lenses.
SUBPHYLA CHELICERATA & MYRIAPODA 34. All the members of these subphyla are terrestrial. The major group in Chelicerata is the class Arachnida.
35. Class Arachnida have a body divided into a cephalothorax and an abdomen. The cephalothorax in arachnids usually has 1 pair of chelicerae, 1 pair of _____ (used for holding food and chewing.), and 4 pairs of walking legs.
37. Spiders can range from ½ mm to 9 cm. • The chelicerae are modified as _____ and are used to inject venom into prey. The venom is produced by poison glands and flows through ducts in the chelicera to the tips of the fangs.
38. Most spiders have _____ simple eyes. Each eye has a single lens. • On the tip of the abdomen of many spiders are 3 pairs of spinnerets. Each spinneret is made of hundreds of microscopic tubes that connect the silk glands to the abdomen.
39. A protein-containing fluid produced in the silk gland hardens into threads as it is pulled from the spinnerets. The silk is used to make webs, build nests, and protect eggs.
