Chapter 15: Gnathiferans and Smaller Lophotrochozoans

Phylum Gnathostomulida roots

ganthos (mouth) and stoma (opening)

small, delicate, worm-like animals found in fine sediments near coastlines; can tolerate deep water

phylum gnathostomulida

phylum gnathostomulida epidermal cells

monociliated

phylum gnathostomulida body cavity

acoelomate

in phylum gnathostomulida, jaws lead to

a simple, blind gut

phylum gnathostomulida reproduction

internal cross-fertilization

common name of phylum gnathostomulida

jaw worms

phylum micrognathozoa monotypic species

limnognathia maerski

three pairs of jaws

phylum gnathostomulida

phylum gnathostomulida reproductive organs

female only

phylum gnathostomulida movement

cilia and ciliary pad that secretes glue

phylum rotifera roots

rota (wheel) and fera (bearing)

phylum rotifera unique organ

corona (wheel) organ for movement and feeding

what phylum has high variation with some desiccating and surviving for years

rotifera

phylum rotifera external features

ciliated corona, nonciliated body
cuticle layer
narrow foot with 1-4 toes with pedal glands for adhesion

phylum rotifera movement

creeping, swimming, or both

phylum rotifera has what under the cuticle

syncytial epidermis

phylum rotifera body cavity

pseudocoel

phylum rotifera digestive system

complete with mastax and hard jaws (trophi)

phylum rotifera excretory system

protonephridial tubules with flame cells

phylum rotifera nervous system

bilobed brain, paired eyespots, sensory bristles, dorsal antennae

phylum rotifera reproduction

dioecious

what class in phylum rotifera has unknown males

bdelloidea

what class in phylum rotifera has seasonal males

monogonoata

phylum rotifera amictic eggs

diploid and develop parthenogenetically

phylum rotifera mictic eggs

fertilized to form amictic females

classes of phylum rotifera

seisonidea, bdelloidea, monogonoata

class seisonidea characteristics

vestigial corona
similar sexes

class bdelloidea characteristics

swimming/creeping
pathogenetic
males unknown

class monogonata characteristics

swimming/sessile
3 egg types

phylum acanthocephala roots

akantha (spine) and kephale (head)

cylindrical and has retractable proboscis with spines for attachment

phylum acanthocephala

cosmopolitan and all parasitic

acanthocephala

phylum acanthocephala lacunar system

increases surface area, diffusion for nutrient exchange

phylum acanthocephala nervous system

reduced

phylum acanthocephala digestive system

no digestive tract

phylum acanthocephala reproduction

dioecious

phylum acanthocephala life cycle

eggs from feces > insect > acanthor > acanthella > cystacanth > pig/rat > intestine

where are phylum cycliophora found

mouthparts of decapod crustaceans

phylum cycliophora feeding

eats bacteria/food particles dropped by host

phylum cycliophora body cavity

acoelomate

phylum cycliophora digestive system

u-shaped gut

phylum cycliophora reproduction

sexual and asexual with chordoid larvae that swim to hosts

phylum gastrotricha roots

gaster (stomach) and thrix (hair)

small, dorsoventrally flattened and aquatic

phylum gastrotricha

phylum gastrotricha movement

glide on substrates or in interstitial spaces

phylum gastrotricha longitudinal or circular muscles more developed?

longitudinal

phylum gastrotricha gas exchange by ____, meaning no ____ systems

diffusion, circulatory or respiratory

phylum gastrotricha digestive system

complete

phylum gastrotricha feeds on

detritus, bacteria, algae, protozoa

phylum gastrotricha excretory system

solenocytes instead of flame cells

hermaphroditic but function as parthenogenetic females
eggs survive harsh conditions and remain dormant for years

phylum gastrotricha

phylum entoprocta roots

entos (within) and proktos (anus)

mostly marine; some commensals on marine annelids

phylum entoprocta

resemble cnidarians with ciliated tentacles
microscopic, stalked, ciliary feeders

phylum entoprocta

phylum entoprocta calyx

cup shaped with tentacles

phylum entoprocta muscles

longitudinal only
tentacles roll inward but cannot retract

phylum entoprocta digestive system

u shaped

phylum entoprocta body cavity

pseudocoelom

phylum entoprocta nervous system

nerve ganglion beside stomach

phylum entoprocta lack what systems

circulatory or respiratory

phylum entoprocta reproduction

sexual and asexual

why is phyla lophophora controversial

mix of protostome and deuterostome traits

common features of lophophora

lophophore and u-shaped gut

phylum of lophophora

ectoprotca, brachiopoda, phoronida

ectoprocta roots

ektos (outside) and proktos (anus)

phylum entoprocta common name

bryozoa (moss animals)

sessile colony builders, individuals called zooids

phylum ectoprocta

phylum ectoprocta extend lophophores to

filter feed

exoskeleton in phylum ectoprocta

zoecium

zooid structure

polypide (feeding) and cystid (body wall)

phylum ectoprocta digestion

extracellular in stomach
intracellular in intestine

phylum ectoprocta reproduction

hermaphroditic, brooding, polyembryony, ancestrula

hermaphroditic

both male and female sex organs

brooding

brood eggs

polyembryony

multiple embryos from one

ancestrula

colonies form from a single zooid via asexual budding

phylum brachiopoda roots

brachion (arm) and pous/podos (foot)

phylum brachiopoda common name

lamp shells

phylum that resembles bivalve molluscs

brachiopoda

phylum brachiopoda valves

dorsal and ventral

phylum brachiopoda attachment

directly or by pedicel (a stalk)

phylum brachiopoda circulatory systerm

open with a contractile heart

phylum brachiopoda reproduction

dioecious, external fertilization
juveniles resemble adults > pedicel attaches > adult life

phylum phoronida roots

lo, white heifer

phylum phoronida common name

fan worms

small, wormlike animals found in shallow coastal waters

phylum phoronida

secretes a tube and lives there their whole life

phoronida

phylum phoronida digestive system

u shaped

contractile blood vessels but not a closed circulatory system, no heart

phylum phoronida

phylum phoronida reproduction

monoecious
free swimming ciliated larvae (actinotroch)

phylum phoronida development

larvae secretes tube > sessile adults