BIOL 3454 1st Edition Lecture 23 Lecture 11 7 I II III IV V Spider reproduction a Courtship ritual before mating b Male usually spins a small web deposits sperm then picks it up in pedipalps c He then inserts pedipalps into females genital opening d Female lays eggs in silken net may carry it or attach it to something young usually remain in cocoon for a few weeks then disperse Dangerous spiders of the US a Black widows 5 species i Neurotoxic painful venom b Brown recluses 13 species i Hemotoxic digestive venom Order Scorpiones scorpions a 1400 species b Probably most ancient of the arachnids c Predatory mostly on insects and spiders sieze with pedipalps and shred with chelicerae d Short cephalothorax with chelicera pedipalps walking legs one pair of big median eyes 2 5 pairs of small lateral eyes e Postabdomen or metasoma of 5 segments with a stinger on the end of the tail f Comblike pectines that serve as tactile organs g Reproduction i Male does a complex mating dance while holding females chelae as he steps back and forth ii Sometimes stings her on edge of cephalothorax foreplay iii Male deposits spermatophore on substrate then female picks it up iv Brood and nourish young in females reproductive tract v Babies crawl onto mothers back until first molt then they disperse Order Solpugida sun or camel spider a In TX b Non venomous c Shred prey with large chelicerae d Up to 15cm across e Usually in desert habitats f Very high metabolism Order Opiliones harvestmen a Daddy longlegs b 5000 species c Abdomen and cephalothorax rounded and broadly joined no pedicel d Abdomen with external segmentation e 4 pairs of legs that end in claws can be lost and regenerate 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 VI VII VIII f Carnivorous but mostly scavengers g Non venomous Order Acari ticks and mites a 40 000 species b Most medically important arachnids c Largest about an inch long d Most habitats on earth e Many species parasitic for at least part of their life cycle f Anatomy i Complete fusion of cephalothorax and abdomen ii No division or sefmentation iii Mouthparts on anterior projection called capitulum iv Chelicera for gripping and tearing food v Base of pedipalps forms hypostome vi Rostrum or tectum extends dorsally over mouth vii Usually 4 pairs of legs viii Most transfer sperm directly some use spermatorphores ix Larvae with 6 legs one or more are 8 legged nymphal stages Subphylym Myriapoda a Means many footed b 2 tagmata head and trunk paired appendages on each trunk segment c Use trachea to carry respiratory gasses to and from all body cells another independent evolutionary event from arachnids and insects d Excretion through malpihgian tubules another evolutionary event from chelicerata Class Chilopoda the centipedes a Roots Greek cheilos margin or tip pous or podos foot b Extremely carnivorous c Up to 30cm long d A few dangerously venomous to humans e A few to 177 segments each segment with the exception of the one behind head and last 2 have 1 pair of jointed legs f Appendages of first segment make venomous claws g One pair of antennae mandibles and 1 or 2 pairs of maxillae h Pair of eyes on top of head are just froups of ocelli i Digestive system straight tube j Respiratory through a pair of spiracles in each segment k Sexes separate with unpaired gonads and paired ducts l Some lay eggs while others give birth to young no metamorphosis m Centipedes are totally consumed with predation
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