Presentation on theme: "ABDI ISSAK FINNBAR MARTIN VALON DAKA Kingdom: Anamalia Phylum:Arthropoda."— Presentation transcript:
ABDI ISSAK FINNBAR MARTIN VALON DAKA Kingdom: Anamalia Phylum:Arthropoda
Types of Arthropod There are three main groups of Arthropods: Arachnids: Insects with 8 legs Crustacean : Free living aquatic animals Myriapoda: Creatures with many legs up to 375 pairs. (750 legs)
Anatomy Arthropods have jointed legs, head and segment body, otherwise known as the thorax. Their bodies are covered with a hard shell or a hard outer skin called exoskeleton. With crustaceans the exoskeleton is known as the carapace and hides the body parts.
Physiology Arthropod physiology for breathing has thankfully restricted the maximum size they can achieve. As has their reliance on their exoskeleton which cannot support the weight of an animal beyond a fairly small size. Although some arthropods are large. The arthropods bloodstream is open. The coelom is much small and most of the spaces inside it’s body are body cavities.
Locomotion The walk of an arthropod walk is made up of a propulsive backstroke, and the recovery forward stoke. While it uses it’s remoter, the foot is in contact with the substrate, and during the promoter it is raised. The promotor/remotor sequence is known as a step cycle. Arthropods move the same leg on each side of the body at the same time. This walking technique is less stable than out-of-phase walking, and is generally practiced by arthropods walking underwater
Obtaining Food Arachnids: They engage in many ways to obtain food. Some spiders trap their victims in silken webs and kill them with a poisonous bite. Others ambush their prey and overpower them with their strong legs before biting them. Scorpions use their claws to capture and kill prey, or else they kill them with a venomous sting. Sun spiders use lightning speed and their massive mouthparts to outrun and tear apart prey
Crustacean: Some crustaceans like shrimp and Krill use filter feeding to obtain their foods. They feed by straining suspended matter and food particles from the water. Other crustaceans such as crabs and lobsters are scavengers and are predators. They use there claws to attack prey, crush them and then eat them.
Myriapoda: The centipede (a type of Myriapoda) has a gland in its head that fills the fangs with poison. The centipede uses this poison to kill its prey. Centipedes have poor eyesight and detect prey by their movement and vibrations. Mostly centipedes will not eat any dead matter but some other Myriapods (like millipedes) will.
Diet Arachnids Arachnids attack and kill small animals, especially insects and their relatives, and then feed on their body fluids. Since they cannot chew most arachnids must first digest their food outside their bodies. They pierce tissues with their mouthparts and inject them with digestive chemicals, turning them into fluids. The fluids are then sucked through the mouth and into the body.
Crustaceans: Crabs which are a known type of Crustacean usually feed on algae but take in any food including other Crustaceans. For the most part mixed diet of plant and animal matter result in fastest growth of the Crustacean species.
Myriapoda: Myriapods eat different types of food. Some are carnivores, which means they eat other mini-beasts. Others are herbivores, which means they eat plants. Centipedes are predators so they feed on other mini- beasts. They hunt at night and are poisonous to other animals. Millipedes eat dead plants and animals. Millipedes are useful because they help clear away rotting vegetation.
Digestion Arachnids: The digestive system is a tube that begins with the mouth, situated below the chelicerae, and leads into the pharynx, then into the esophagus, and from there into the sucking stomach, which has heavy muscles and serves to pump the partially digested food into the mid-gut, where special enzymes digest the food.
Crustaceans: Digestion occurs in the foregut which shows the greatest range of structure; in some crustacean species it is a simple tube, but in crustacean's with 5 pairs of feet it reaches great complication in forming a structure called the gastric mills. This consists of a series of calcified plates, or small bone, that are moved against each other by powerful muscles, making an efficient grinding apparatus. The junction between the mill and the midgut is guarded by a filter.
Myriapoda: The digestive system is a gut that runs from the mouth to the anus. The gut is lined with a protective outer covering called a chitin, that is shed every so often.
Excretion Undigested food becomes solid waste It leaves the anus of the animal. Terrestrial arthropods remove nitrogen-containing wastes by: using a set of Malpighian tubules Found in the body sinuses remove waste from blood, concentrate them, and then add undigested food allowing it to leave through anus may have small excretory glands at bases of legs. Aquatic arthropods remove nitrogen-containing wastes by... through a pair of green glands found by base of antennae eliminated through a pair of opening on the head.
Circulation Arthropods' primary internal cavity is a hemocoel, which accommodates their internal organs and through which their bloodcirculates; they have open circulatory systems. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. Their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, and their brains are formed by fusion of the ganglia of these segments and encircle the esophagus
Respiration Respiration in the arthropods occurs through microscopic holes in the exoskeleton and body wall. Branching networks called tracheae extend from these holes to all parts of an arthropod's body.
Life Cycle Arthropods begin as eggs and can follow several different life cycles, depending on the group. Some insects hatch as miniature adults, while others hatch as nymphs and develop by stages into adults. Still others hatch as larvae and enter a resting stage as pupae, during which they may be enclosed in a cocoon and go through internal changes before emerging as adults. During their various developmental stages, known as metamorphosis, arthropods may shed their outer covering several times. http://videos.howstuffworks.com/discovery/27695-assignment- discovery-arthropod-locomotion-video.htm http://videos.howstuffworks.com/discovery/27695-assignment- discovery-arthropod-locomotion-video.htm