BIOL 3454 1nd Edition Lecture 17 I II III IV V VI Communication a Lots of studies on squid and octopus b Visual signals extremely important c Body motions and color changes through chromatophores d Ink from and ink gland for defense Reproduction a Sexes separate b One arm of adult males modified in to a hectocotylus plucks the spermatophore sperm packet and insert into female mantel cavity Cephalopod taxonomy Nautiloidea a One pair of gills b Only one surviving genus with 5 species Cephalopod taxonomy Ammonoidea a All extinct in the certaceous b Extinct before the asteroid impact c Chambered shwlls with more developed septa than nautiloids Cephalopod taxonomy Coeloidea a Everything extant besides Nautiloidea b Vampire squid and vampire octopus don t know which Class Bilvalvia Pelcopoda a Hatchet footed animals nick named b Mussels clams scallops oysters shipworms c Sedentary filter feeders d Marine and freshwater e Very important to humans for food consumption f Bivalve shell form and function i 2 shells held together by inge ligament ii Umbo oldest part of the shell growth emanates from it iii Pearl form when foreign objects lodges between mantle and shell g Body mantel and locomotion i Visceral mass suspended from dorsal midline ctenidia hand on each side of foot ii Some clams have a mantel modified into long siphons iii Most push foot between valves muscles contract for movement extra blood increases size to be an anchor into substrate iv Scallops and file shells swim by pushing water out of the mantle edge forcefully h Gills and feeding i Gas exchange occurs in both mantle and gills ii Some have modified these gills through lengthening of filaments can interlock to form lamellae iii Most bivalves filter feeders respiration brings both food and gas exchange 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 iv One group shipworms or termites of the sea bore into and eat wood very damaging i Internal structures i Floor of most folded into ciliary tracts ii Particles sorted nonfood excreted food directed to digestive gland or engulfed by amebocyte iii Style sac has a crystalline style and whirls by ciliary action keeps digestive processes moving iv 3 chambered hearts v 2 u shaped kidneys vi 3 pairs of ganglia separate from each other vii Sense organs poorly developed some have decent eyes j Reproduction i Sexes separate ii Gametes usually discharge into water iii Glochidium specialized veliger larvae iv Some females hold glochidia in a specialized pouch called conglutinate specific shape for each species k Class Scaphopoda i Tusk shells or tooth shells one piece tubular shell conical at both ends ii Benthic from shallow to 6000m deep iii No gills iv Have long feeding tentacles with ciliated knobs called captacula v Radula carries food to gizzard vi No eyes sensory tentacles or osphradia vii Sexes separate trochophore larvae VII Test ancestral molluscs look like What direction did molluscs go shell no shell brains fast VIII Chapter 17 IX Annelids and Allies a Coelomate prostoomes b Coelom through schizocoely c Spiral mosaic cleavage d 3 phyla annelida Achiura and Sipuncula X Phylum Annelida a Latin root annelus little ring b Earthworms leeches polychaete worms c Divided into segments called metameres d Division into segments called metamerism e Rings called annuli f Some have chitinous bristles called setae g World wide almost all habitats h Characteristics i Unique head parapodia ancestral ii Bilateral symmetry triploblastic iii Epithelium secretes moist cuticle iv Digestive system complete and not segmented v Asexual reproduction by fission and fragmentation vi Typically a pair of kidney like organs per segment for waste removal vii Closed circulatory system i Basic body plan i Usually 2 two part head a prostomuom and a peristomium ii Terminal portion called a pygidium iii New segments just in front of the pygidium older at the front iv Each segment usually with its own circulatory respiratory nervous and excretory structures v Exceptr for leeches coelom filled with fluid to make a hydrostatic skeleton XI Class Polychaeta a Greek poly many chaite long hair b Most marine c Up to 3m long d Live under rocks in crevices shells in sediment a few planktonic e Significant component of marine food chains f Form and function i Differentiated head with food sense organs paired parapodia on most segments ii Many setae iii Usually divided into sedentary and mobile forms iv Postomoum sometimes retractile holds eyes tentacles sensory palps v Peristomium surrounds mouth has setae palps and chitinous jaws in predatory forms vi Forefut midgut and hindgut vii Mobile species scavengers or predators sedentary species usually filter feeders viii Parapodia and gills for gas exchange some small species just use diffusion across body wall ix 3 types of kidneys depending on speacies protonephridia metanephridia or a mix x Nephrostome opens into coelom xi Double ventral nerve cord xii Possess eye statocysts nuchal organs xiii Everything from simple eyespot to eyes with good visual acuity and complicated structures lens and cornea xiv Nuchal pits chemoreceptivce xv Usually no permanent sex organs uslaly separate sexes xvi Gonads temporary swlling gametes shed into coelom xvii Fertilization external larvae called trochophore