BIOL 3454 1st Edition Lecture 25lecture 11/12I. subclass Cirripedia a. barnacles plus 3 smaller orders of burrowing or parasitic formsb. sessile as adults c. carapace surrounds body and secretes shell of calcareous platesd. head reduced no abdomen thoracic legs long many jointed cirri with harilike setaee. cirri extended between plates for filter feeding f. most hermaohroditic have internal fertilization g. free living cyprid larvae that attach by their first antennae then metamorphose into adult formh. longest penis in relation to body size of any animal II. class Malacostracaa. 20,000 species largest class great diversity b. Order isopoda – the roly polys and ectc. Order amphipoda – like isopods but compressed laterallyd. Oder euphausiacea – the krille. Order decapoda – tasty guys lobsters, crabs, shrimp f. Very important economically for food, scavenging and forming the base of many food websIII. Order isopoda a. Have invaded terrestrial habitats all the way to very deep water b. Dorsoventrally flattened c. No carapaced. Have sessile compound eyese. Maxillipeds are the first pair of thoracic limbs and others are exopods f. Development usually direct a few parasitic forms have complex life cycles IV. Order Amphipodaa. Resemble isopods but compressed laterallyb. Gills in typical malacostracan thoracic position c. Thoracic and abdominal limbs differ in function (1 pair for swimming and the other for jumping)d. Direct development e. No metamorphosis V. Order Euphausiaceaa. ~90 species known as the krillb. 3-6cm longc. Carapace fused with all thoracic segments does not entirely enclose their gillsd. No maxillipeds but have thoracic limbs with expopods e. Many bioluminescent bc of an organ called a photophore These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.f. Very important to marine food wedsVI. Order Decapodaa. ~18,000 species b. 3 pairs of maxillipeds c. 5 pairs of walking legsd. Some walking legs modified to form chalae (claws)e. Largest arthropod is Japanese spider crab (4m)f. Homer Simpson’s crab is PinchyVII. Hexapods a. Most dominant group i. Insects are the most important group to humans ii. Extremely important in food websiii. Vectors of disease iv. Are human health risks themselves v. Agricultural pests vi. Locust outbreaks can cover 20% of the land area of the earth and contain billions of individuals vii. Multitude of invasive insects changed N. American forestsviii. Exist in all terrestrial habitats ix. More species than all other groups of all lifeforms combinedb. Subphylum Hexapodai. Named for the presence of 6 legs all uniramous ii. 3 tagmata – head, thorax and abdomen iii. 2 classes 1. Entognatha – orders protura, dipluran and collembolan2. Insect – everyone elseiv. Class Insecta 1. Roots Latin: insectus (cut into)2. 1.1 million described species and many more not described 3. Ectognathus mouthparts 4. Usually 2 pairs of wings 5. Exoskeleton formed from a complex system of plates called sclerites connected by flexible hinge joints6. Much more homogenous in tagmatization than crustaceans 7. External form and function a. Usually have a pair of large compound eyes b. Pair of antennae (function as tactile, olfactory and auditory)c. 3 ocellid. Mouthparts usually a labrum, pair of mandibles, a pair of maxillae, a labium and a hypopharynxe. Thorax with 3 segments (prothorax, mesothorax and metathorax) each have a pair of legs and wings on the last 2 segments f. Wings are cuticular extensions of the epidermis g. Legs highly modifiable h. Abdomen has 9-11 segmentsi. Sometimes with posterior cerci from 11th segment, genitalia emerge from 8th and or 9th segment j. All mouthparts antennae legs cerci and ovipositors are all modified appendages 8. Walking in insects a. Each individual static state usually involves a triangle of the first and last leg of one side and middle leg of the opposite side b. Very stable 3 of the 6 on the ground at any time c. Water striders extreme example that use expanded legs to sit onsurface tension 9. Flying in insects a. Only invertebrates that can fly fully functional wings 400myab. Immense variation in wing design flies only have 1 pair beetles make 1st pair into hard outer covering, butterflies cover in scales and hairs in caddisfliesc. Direct flight muscles – attached to wing itself d. Indirect flight muscles – not attached to wing, cause movement by altering shape of thorax10. Neural control of flight muscles a. Synchronous – single nerve impulse stimulates a muscle contraction and 1 wing stroke, much slower wing beat (dragon flies and butterflies)b. Asynchronous – complex action that requires energy storage in part of the thoracic cuticle, muscle contractions not in phase with nerve stimulation, much fast wing beat (flies, beetles and ect)11. Insect nutrition a. Forgut – mouth with salivary glands esophagus crop fro storage and gizzard for grinding b. Midgut – stomach and gastric cecac. Hindgut – intestine rectum and anusd. No absorption in foregut e. Most absorption in midgut f. Hindgut for resorption of water and ions12. Feeding modesa. Most insects phytophagous (feed on plant tissues and their juices)b. Many beetles and many larvae are saprophagous (feed on dead animals)c. Some are predaceous (feed on live animals)d. Many are parasitic – exhibit hyperparasitism (are parasites and parasitiezed), parasitoids always kill their host eventually13. Form follow function for feeding a. Insects have tremendously diverse feeding strategies so their mouthparts are almost infinitely modifiableb. Sucking mouthparts – usually form a tube, in a mosquito all mouthparts are elongated together in a needlelike stylet called afascicle but in butterflies it’s a proboscis c. Sponging of lapping mouthparts – flies have little spinges that absorb soft food some pierce and then lap fluid upd. Chewing mothparts – many herbivorous insects toothed plates grind or tear