Presentation on theme: "Arthropods Organisms with jointed appendages, a segmented body and a tough exoskeleton."— Presentation transcript:
1ArthropodsOrganisms with jointed appendages, a segmented body and a tough exoskeleton
2Key Terms Exoskeleton – a tough external covering Chitin – a carbohydrate that is a component of the exoskeletonAppendage – structures that extend from the body like legs and antennaeTrachael tube – a network of branching tubes that extend throughout the body through which the arthropod respires
3Key Terms Spiracle – openings located along the side of the body Book lung – organs that have layers of respiratory tissue stacked like the pages of the book (generally found in spiders)Malphighian tubule – saclike organs that extract wastes from the bloodMolting – the shedding of the exoskeleton of an arthropod
4Sub-phyla of Arthropods Crustaceans – typically have two pairs of antennae, two or three body segments, and chewing mouthparts called mandibles (include crayfish, lobsters, and crabs)Chelicerates – have mouthparts called chelicerae and two body sections, and nearly all have four pairs of walking legs (include spiders, ticks, horseshoe crabs)Insects – body is divided into three parts – head, abdomen and thorax, three pairs of legs are attached to the thorax. (includes grasshoppers, etc)
5Crustaceans Crustaceans – Two pairs of antennae, two or three body segments, and chewing mouthparts called mandibles (EX.crayfish, lobsters, and crabs)Body plan has two segments (Cephalothorax and abdomen).Carapace covers the cephalothoraxAppendages vary in location and functionMandibles – mouthpart adapted for chewing or grinding of food.
6CrustaceansChelipeds – first pair of legs that bear large claws modified to catch, pick up, crush, and cut food.Swimmerets – flipperlike appendages used for swimming located along the abdomenRespires through gills on the underside of the body
8CheliceratesHave two pairs of appendages attached near the mouth adapted as mouthpartsChelicerae – first pair that contains fangs that are used to stab and paralyze prey.Pedipalps – longer than the chelicerae and usually modified to grab preyThis class includes horseshoe crabs and spiders, mites, ticks and scorpions
9ArachnidsInclude horseshoe crabs, spiders, mites and ticks, and scorpionsSpiders do not have jaws to chew their prey, but inject venom which paralyzes their prey and then liquifies the preys insides so it can suck the tissues into their stomachSpiders have spinnerets for silk
10ArachnidsMites and ticks are often parasitic. The mouthparts or chelicerae and pedipalps are designed for digging into their host’s tissues.Ticks can transmit some serious diseases such as Lyme Disease or Rocky Mountain Spotted Fever.
11Arachnids Scorpions usually are found in warm areas Their pedipalps are enlarged to form clawsThe abdomen has a stinger that carries venom that can kill or paralyze prey.These critters will chew their prey using their chelicerae.
13Dangerous Spiders in the US Black WidowBlack shinky body with red/orange hourglass shape on abdomenVenom – neurotoxic (affect nervous system)Bites can be fatal (general in small children or elderly individuals)
14Dangerous Spiders in the US Brown RecluseViolin shape on cephalothoraxVenom – hemolytic (affect blood cells thus killing tissues)... death of tissues surrounding biteBites are fatal to small children and older individuals
15Dangerous Spiders in the US Brown RecluseViolin shape on cephalothoraxVenom – hemolytic (affect blood cells thus killing tissues)... death of tissues surrounding biteBites are fatal to small children and older individuals
16FYI: Black Widow Bite Renders no pain… at the beginning Then it feels like damage by a small pin. As the below picture shows, two tiny red spots can be generally seen at the center point of the swollen area.But soon the venom spreads and the injury grows in size, reddeness, and dead tissue.It is very necessary that the victim attends to an emergency room in day number one; also, succeeding in trapping the spider to show it to the doctor could be helpful at the time of prescribing the exact medication.
17InsectsAlso known as Uniramians and have one pair of antenna, jaws and unbranched appendages.Centipedes (Chilopoda) – have many legs, the number depends on the speciesAre carnivores and have venomous claws to catch, stun or kill their preyMust live in the moist area since their spiracles will not close and their exoskeleton is not waterproof.
18InsectsMillipedes (Diplopoda) – highly segmented body and each segment has 2 pair of legsTimid creatures and feed off of dead or decaying materialLive under rocks and in logs.Roll into a ball to protect the soft undersides when disturbed.
19InsectsInsects (Insecta) – have body divided into three segments (head, thorax and abdomen) and three pairs of legs attached to the thorax.Typical insect will also have a pair of antenna, a pair of compound eyes on the head, two pairs of wings on the thorax and tracheal tubes for respiration.
20Insects - ResponsesMany sense organs – eyes, antennae with chemical receptors for taste and smell and also in the mouthparts and legsSensory hairs that detect movements in their surroundings.Ears are also well developed and are found behind the legs in the grasshopper.
21Insects – FeedingVarious types of mouthparts – and saliva that performs many functionsChewing – used mandiblesSucking – moth uses a proboscisSpongelike – used a spongelike mouthpart to lap up foodPiercing – for penetrating the object upon which to feed
23Insects - Metamorphosis Growth and development includes metamorphosis where the body and shape of the organism changesComplete metamorphosis4 basic stages (egg, larva, pupa, and adult)Incomplete metamorphosis3 basic stages (egg, nymph, and adult)
24Insects Interactions with Humans Many negative impacts for humans – Can you name a few?
25Insects Interactions with Humans How about listing some of the benefits from insects?
26Insect CommunicationVisual cues – such as fireflies lights to communicate with females.Chemical signals – aka pheromones - which are specific chemical messengers that affect the behavior or development of other individuals of the same species.When could humans use pheromones within their interactions with insects?
27Insect SocietiesAnts, bees, termites and some of their relatives form complex associations called societies.Specialized individuals within societies form castes where the individual has a special body form for its role (ex. Queen bee in the hive, worker bees, etc)
28Insect Communication in Societies A system of communication is necessary for functioning within a society.Ex. Ants find food and leave a trail for others to follow and retrieve foodBees have two basic dances for communication – waggle dance and round dance