bio unit 6

bivalvia

bivalvia

mollusca, clams, oysters, scallops, mussels, 2 separate shells of CaCO3, reproduce sexually, 2 larval stages; trochophore & veliger

umbo

hinge

veliger

second larval stage of bivalvia

cephalopoda

mollusca, nautlilus, cuttlefish, squid, octopuses, well developed head, long tentacles derived from foot, most do not have shells, large brains & camera eyes, predators, move through fins & propulsion, radula & beak, internal sexual reproduction

ammonites

shelled cephalopods that used to be dominant predators, vanished with dinosaurs

nautilus

only shelled group of cephalopods today

metamerism

segmented body plan, repeating unit of metameres

annelida (lophotrochozoan)

segmented worms, metamerism, coelem function as hydrostatic skeleton, sexual & asexual reproduction

chaete

hairs that extend from parapodia

parapodia

appendages that function in motility in annelids

polychaeta

annelid lineage that retained many chaete, mostly marine

clitellata

annelid lineage that lost or have reduce chaete, include 2 monophyletic groups; oligochoeta (earthworms), hirudinea (leeches)

oligochaeta

class of annelid, earthworms, deposit feeders

sexual reproduction of worm

align with another worm, produce sperm at the same time, secretes cocoon that collects sperm & egg, moves across body of worm into soil, new worm will grow

hirudinea

class of annelid, leeches, blood sucking parasites, ectoparasite

hirudin

anticoagulant agent secreted by leeches

clitellum

organ in worms that secretes cocoon for sexual reproduction

Phylum Platyhelminthes

Flatworms, 3 tissue layers, acoelomates, gastrovascular cavity, only one opening, reproduce sexually and asexually, hermaphrodites, can self fertilize

tubelarians

free-moving flatworms, move via cilia

definitive host

where sexual reproduction occurs

intermediate host

where asexual reproduction occurs

trematodes

live as parasite in or on animals, alternate sexual and asexual stages, can mimic same proteins as host to escape immune system, insides almost completely filled by reproductive organs, release molecules that manipulate host’s immune system to tolerate parasite

tapeworms

part of cestoda, parasites of vertebrates, lack digestive system, anterior end (scolex) has suckers to attach worm to intestinal tract of host

proglottids

sex organs, eggs that are released in the hosts feces from tapeworms

lophotrocozoan lineages

bivlalves, gastropods, chitons, cephalopods

foot

muscle at base of mollusks, used for movement

visceral mass

contains instestinal mass in mollusks

mantle

tissue layer covering visceral mass

lopophore

structure that rings mouth, functions in suspension feeding (found in lophotrocozoans)

2 things required to be lophotrocozoan

lopophore or trochophore except for rotifera

trochophore

larval stage of lophotrocozoans

rotifera

phyla of lophotrocozoans, has pseudocoelom, feeds with corona, asexual & sexual reproduction, no lopophore or trochophore, parthenogenesis

parthenogenesis

females produce females from unfertilized eggs (rotifera)

mollusca

phylum of lophotrochozoans, made up of foot, visceral mass, and mantle, all contain trochophore larvae

mantle cavity

water filled area formed by extension of mantle over visceral mass, contains gills, anus, excretory pores

radula

rasp like structure from mouth, used to scrape food, constantly generating new teeth at one end, scrapes food from rocks

chitons

mollusk with 8 CaCO3 plates that form protective shell, sexual reproduction, trochophore larvae

gastropoda

mollusk with large muscular foot on ventral side, some have shells and some dont, asexual through parthenogenesis and sexual, torsion

torsion

when visceral mass is rotated 180, causes anus & mantle to end up above head, process during embryonic development, U shaped digestive system

1. head can be retracted

2. prevents sediment from getting into mantle cavity

3. olfactory organ is in front, can sample area before entering

4. repostion shell, better balance

torsion advantages

lophotrochozoa growth

extend body to grow

ecdysozoans

have to molt exoskeleton and then extend body to grow

lophotrochozoan groups

rotifera, platyhelminthes, annelida, mollusca

ecdysozoan groups

nematoda, tardigrada, onychophera, arthropoda

phylum nematode

ecdysozoan, nonsegmented pseudocoelomates, covered by cuticle, complete gut, no appendages, no circulatory system, can only bend bodies back and forth (only longitudinal muscles), reproduce sexually, sexes are diecious, internal fertilization with non flagellated sperm, some parasitic

tardigrades

microscopic animals, live in marine freshwater environment, see through little creatures with little legs, feed by sucking fluids or detritus

onychophores

small caterpillar like worms, prey on small invertebrates, also called velvet worms

tagmate

segmented bodies w/fused segements

arthropods morphological features

segmented bodies, complex jointed exoskeletons made of chitin, open circulatory system, hemocoel, paired joined appendages, some with compound eyes and pair antennae

hemocoel

body cavity that provides space for internal organs & circulation of fluids

arthropods appendage functions

sensing environments, locomotion, feeding, and gas exchange

sub phylum arthropods

cheliceriforms, myriapoda, hexapeda, crustacea

cheliceriforms

body of anterior and posterior regions, anterior region lacks antennae, eyes and six pairs of appendages, contain chelicera, variety of feeding behaviors (horseshoes crabs, spiders, scorpions, ticks, mites)

myriapoda

sexes are separate, internal fertilization, females lay eggs, simple bodies with a series of short segments

hexapoda

body divided inot head, thorax, and abdomen, antennae present, 3 pairs of legs, usually 2 pairs of wings, terrestrial (insects, springtails)

crustacea

body of two or three parts antennae present, chewing mouth parts, three or more pairs of legs, mostly marine and freshwater, cephalothorax, some have carapace (crabs, lobsters, crayfishes, shrimps)

chelicerae

special feeding appendage or chelicerata

biramous

branched appendages, feeding & locomotion

insect characteristics

3 tagmata, one pair of antennae, compound eyes, oceli, 4 sets of mouthparts, 3 pairs of jointed walking legs, 1 or 2 pairs of wings

1. evolve mechanism for exchange gases

2. avoid drying out

protostome adaptations to land

lung in terrestrial snails

evolved from gills of aquatic snails

tracheal system

waxy layer to minimize water loss from body surface, openings to respiratory passages that can be closed

1. evolution of metamorphosis

2. egg that does not dry out on land

reproductive innovations when animals moved to land

viviparous

embryos retained in female body, live birth

oviparous

species that lay eggs, develop independently of mother

ovovivoparous

egg formed in body, embryos nourished by yolk, not direct transfer of nutrients from mother

larvae, juvenile, adult

3 life stages

larvae

look radically different from adults, live in different habitats, eat different foods, sexually immature

juvenile

look and behave like (mini) adults, sexually immature

adults

reproductive stage in life cycle

metamorphosis

change from an immature body type to an adult body type

hemimetabolous metamorphosis

juvenile forms is nymph, look like a mini adult

holometabolous metamorphosis

complete metamorphosis, juvenile individual is called larvae, look diff than adult

pupa

stage where larva is remodeled into an adult

deuterostome phyla

echinodermata, hemichordata, xenoturbellid, chordata

echinoderm

series of branching fluid filled tubes, water vascular system, spiny skin, all marine, larvae bilaterally symmetric, adults radially symmetric (pentameric), part of bilaterians, endoskeleton

5 major lineages of echinoderm

crinoidea, asteroidea, ophiuroidea, echinoidea, holothuroid

water vascular system

, series of branching fluid filed tubes, chambers for hydrostatic skeleton, useful in moving and feeding, tube feet & podia

tube feet

elongated & fluid filled structures used in movement

podia

section of tube feet that can be extended so they can move, also used for feeding, can insert stomach to excrete digestive enzyme so that they can eat, also used in suspension feeding

asteroidea characteristics

5 or more long arms radiating from center, center is mouth/stomach/anus, predators & scavengers, use tube feet, separate sexes, predominant sexual reproduction but can do asexaul reproduction, reproductive organs located in one or more arms

ophiuroidea

brittle stars & basket stars, have 5 long arms radiating from center, used for suspension feeding, brittle stars use arms to whip around (swim) basket starts have bunches of tentacles

echinoidea

sea urchins, globe shaped w spines, crawl on substrates, sand dollars & biscuits are deposit feeders, secondarily bilaterally symmetric, sexual reproduction dominates

holothuroidea

sea cucumbers, sausage shaped, suspension feed, modified tube feet (tentacles) arranged in whorl around mouth, can expel internal organs through mouth to escape predators (evisceration)