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Phylum Arthropoda. “JOINTED LEGS”. Euglossa Bazinga http://www.nydailynews.com/entertainment/tv-movies/bazinga-species-bee-named-big-bang-theory-character-catch-phrase-article-1.1232240. Characteristics of Arthropods.
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Phylum Arthropoda “JOINTED LEGS”
Euglossa Bazinga • http://www.nydailynews.com/entertainment/tv-movies/bazinga-species-bee-named-big-bang-theory-character-catch-phrase-article-1.1232240
Characteristics of Arthropods • Modified segmentation – body regions specialized for specific functions (tagmatization). • Chitinous exoskeleton used for support and protection • Paired, jointed appendages • Growth accompanied by molting (ecdysis)
Characteristics of Arthropods • Ventral nervous system • Reduced coelom • Open circulatory system where blood is released into tissue spaces (hemocoel) • Complete digestive tract • Metamorphosis often present
Exoskeleton of Chitin • Must molt to fit as animal grows larger • External, jointed skeleton which encloses arthropods • Provides support, protection, and prevents water loss • System of levers for muscle attachment and movement • Secreted by epidermal cells
Muscles and Movement: • complex muscular system – both smooth and striated strong muscle contractions – fast, • active movements - muscle strength to body weight ratio of flea greater than that of humans!
Respiratory features • efficient respiratory structures – gills, tracheal tubes, book lungs, spiracles
Internal Features (cont.) • open circulatory systems – has heart and arteries but vessels are open-ended; blood flows out among tissues: there are large open spaces loosely filled with tissues, sinuses, and blood
Internal features • complex digestive system and digestive glands to produce enzymes • Malphighian tubules – used to excrete wastes into intestine
Mandibles • mandibles – jaws that hold, chew, suck, or bite
Spider chelicerae • Act as fangs or pincers to hold food
Pedipalps • act as sensors or handle food
II. Merostomata – horseshoe crabs • “living fossils” – little change in 500 million yrs, much like extinct trilobites • large heavy exoskeletons, live on ocean floor
Crustacea • Crayfish external anatomy
Crustacea • Crayfish head
Crustacea • Crayfish Mouthparts
http://news.sciencemag.org/sciencenow/2012/06/mantis-shrimp-smash.htmlhttp://news.sciencemag.org/sciencenow/2012/06/mantis-shrimp-smash.html
Subphylum Myriapoda • Four classes, two major: • Diplopoda- 2 pairs of legs per segment, body round in cross section. Millipedes • Chilopoda-1 pair of legs per segment, body oval in cross section, poison claws. Centipedes
Pink Dragon Millipede Scolopendra gigantea Vietnamese Centipede House Centipede
Class Insecta • 30 Orders within Class Insecta! • Common features an adult Insect is characterized by: • Body divided into head, thorax, abdomen • Three pairs of legs • Wings
Complete Metamorphosis • larvapupaadult • in ants, beetles, flies, moths, butterflies • Larva – free-living & wormlike eats, grows, & molts • Pupa – most in cocoon while tissues & organs of larva broken down and replaced by adult tissues • Adult – emerges from pupa, ready to reproduce
Reduces competition between adults and immature stages • Ex: Larval crabs feed on plankton, adult crabs prowl sandy bottoms for live prey. • Ex: Caterpillar feeds on leafy vegetables, adult butterfly feeds on nectar from flowers.