Blastocoelomates Phylum Rotifers wheel to bear Gastrotricha stomach hair Acanthocephala thorny head Gnathostomulid a mouth jaw Loricifera corset bear Cycliophora Nemertea snout cavity Diagram SubPhylum Classes Digonata monogonata distinguished by LC 1 Digonata order Seisonida marine males and females order Bdellodea males unknown 2 Monogonata alternate between part of reproduction and parthengentic seasonal none none none None none None Unique Chatacteristics mastax full body spines and cilia Behavorial modification of IH all acanthocepholans do this jaw plates that can scrape food in 6 plates lorica that can extrude spine scalides live on mouthparts of decapods ex Crabs proboscis rhycholcoel special cavity not from Vermiform worm shaped interstitial live in sand deep intestinal habitat in ocean 300m 6 plate lorica has spines Muscular bands retractor muscles retread head neck into lorica mouth dorsoventrally flat cephalized 1 000 species protostome live on mouthparts acelomates mesenchymal oval trunk posterior adhesive disk suspension feeders u shaped ciliated gut males attach to females diffsuion 1 pair protonophridia parasitic 1 100 species live in intestines 20cm recurved hooks on proboseis No mesoderm in gut just in the outer layer of Live in intestines of vertebrates always parasitic have no intestines Vertebrate arthropod intermediate host life cycle systems reduced Proboscis can be excluded receptable retractor muscle hang on intestine with Characterisitcs Trichos hair 1mm ingerstitial elongate dorsoventrally flat Acoelomate adhesive tubes Hermaphroditic Freshwater and solidary not colonial mostly complete gut Corona highly modified used to get food Eutelic set number of somatic cells males reduced absent 1mm 2 000 protoneophridia posterior glands adhesive toes mastax cuticle jaws in pharynx Spines sculpturing sometimes thick Antenny dorsal and latera preform sensory function Pedal glands on toes secrete sticky stuff Corona has variety of forms fig 12 3 Head trunk foot Head has a ciliated organ in circle 1mm Body Plan Regions Body Cavity Symmetry blastocoelomate bilateral Blastocoelomate bilateral blastocoelomate bilateral canthocephalan cephala head trunk 20cm head neck trunk tail 2mm 1mm head and toes with adhesive glands trunk functionally Acoelomate Bilateral Head neck thorax tetractable body in lorica Bilaterally symmetrical blastocoelomat oval trunk posterior adhesive disk in which it attaches to host functionally acoelomate bilateral functionally acoelomate bilateral External Anatomy plates and spines ventral cilia vermiform Cuticular lorica covering most of the body on outside Layered cuticle many layers fiberous plates and spines longitudinal oblique circular muscles More by ventral ciliary gliding looping adhesive tubules Muscles in sheets circular and longitudinal muscles Lacunar system Lemnesci participate in working or extrusion of probasis Ligament sacs extend into animals and support reproductive organs Tegument blastoelom support Sup epidermal muscle mostly longitudinal Mesenchyme helps support e Mouth on oral cone can be inverted spines Head and neck 7 9 rows 1st row Clavoscalids pointed forward Rest of rows Spinoscalids pointed anyway Cilia gilde mucous 2 toes adhesive Body Wall Support Locomotion Feeding Digesition cuticle soft and epidermis epidermal constant nuclei Below that groups of circular and longitudinal muscles occur in bands Within that the blastocoel itself Hydrostatic skeleton Cuticle gelatenou can change pressure and shape tegument syncytial epidermis cilia corona to swim generates current Anchor toes and extend body and extend toes creep Some are sessile and have an adhesive disk digestive tract ciliated Ciliary suspension corona and mastax Corona flushes stuff to pharynx crushed in mastax Other kinds trophi extend out and grab food Some have spines contract and trap prey coronal spines cilia 2 toes with adhesive glands muscles oblique long Muscular pharynx ciliary current Feed on organic material always parasitic lives on intestine of host vertebrate Mouth ventral muscular pharynx scrape food in Complete intestine GI suspension feeders cilia around buccal funnel u shaped ciliated gut no muscle around gut sometimes cilia takes over that role cephalic sense organ on head mouth is anterior epidermis is ciliated dermis muscles circular and longitudinal mesenchyme muscles and hydrostatic skeleton smaller ones move via cilia larger ones rely on muscles active predators some scavenge proboscis everts wraps around prey stylets at end inject proboscis found in rhychocoel muscles eve3rt Circulatory System diffusion protnophridia diffusion protnophridia Some protonphridia Diffusion Lununar system diffusion protnophridia diffusion protnophridia Gas Exchange Excretion diffusion Diffusion diffusion diffusion diffusion diffusion protnophridia diffusion Incomplete gastrointestinal tracts not much anus Nervous System Reproduction and Development Good size cerebral ganglia connected to top pharynx nerve cord Bristles on face area that may be tactile receptors Hermaphroditic or parthenogenetic Direct development Few large eggs Cerebral ganglion bodies for nerve cells grouped together dorsal 2 major longitudinal nerves Clemosensory pits oceli allow to respond to light Touch sensitive bristles oscellious Parthenogenesis most common ability to reproduce without fertilization Mostly dioecious but males small absent reduced Alternation of generation through time depending on Cerebral ganglion with proboscis receptacle have tacktile receptors Sensory pits cilia Protandric males then females or stimultaneous hermaphroties both sexes at same time Circumphary ngeal gland large Large ventral nerve cord ganglionated Spines may be sensory but totally known Internal Fertilization Hermaphroditic Dioecious 1 pair of protonophridia in gonads Higgins larva sheds cuticle 1 pair of protonophridia Males attach to females Separate sexes diecious Females ovarian balls of immature eggs only young females uterine bell meet with sperm outside layer of egg Maturation process digest extracellular closed system single pair of longitudinal vessels epidermal over the surface osmoregulatio n flame bulb nephridia as lateral blood cephalized sensory structures anterior cilia cerebral ganglion long nerve cord 4 lobes circling proboscis statocists regeneration can undergo many transverse fission diecious gonads specialized and extrude gametes environmental factors summer time shed layer