marine bio midterm

what is the form of binomial nomenclature?

genus species

what does a choanocyte do?

creates mechanical power to move water & collect food

what are the two major life stages of cnidarians?

polyp and medusa

what is strobilation?

when a scyphozoa polyp becomes different stacked sections which bud off as ephyrae

how do you denote a new species?

sp. nova = species nova

what is coenosarc?

living tissue that covers stony skeleton in coral (phylum cnidaria, class anthozoa)

what is simplifaction? and give examples

the reduction of biological complexity at different levels —> myxozoa use cnidocytes as anchor?

what are colloblasts and who has them?

ctenophores, a retractable multicellular glue gun

what are the three defining features of molluscs?

mantle/mantle cavity, radula, locomotory foot

what is a superficial similarity and give examples?

things that look similar but have distinct body plans —> snail limpet and monoplacophoran (coiled vs uncoiled), anthozoa coral and bryozoan moss animal (radial vs bilateral symmetry), ctenophore and cnidocyte (colloblasts vs cnidocytes)

explain the Raup model

model for describing snail shells: Translation (distance down axis), Whorl expansion rate (how big the rings are), and D (distance from central axis)

what are siphons and who has them?

bivalves —> mantle is modified to form incurrent & excurrent siphons that pump water through organism for gas exchange & filter feeding. indep. evolution with tunicata (sea squirts)w

what is special about oysters?

bivalves, very strong filter (like a pump) to help sea clean

what are the characteristics of cephalopods?

direct development, predators w/beak like jaws, swim via jet propulsion, head & sensory organs, foot is lobed & forms arms & tentacles

explain the trend in brachiopod/bivalve biodiversity

when brachiopods started to sharply decline (go extinct) the number of bivalves began to rise

what is special about flatworms?

they are able to regenerate

what is special about arrow worms?

they have a complex jaw and are second in abundance in ocean

what are the two most abundant animals in the ocean?

1 —> copepods, 2 —> arrow worms (chaetognatha)

what is instar and what group does it belong to?

instar are the developmental milestones/stages between each molt of the ecdysozoa superphylum

what is defining about arthropods?

segmented body: head, thorax, abdomen

what is convergent evolution and give examples?

independent evolution of similar features in unrelated species. ex segmentation in arthropoda and annelida, siphons in bivalves and tunicata, adaptation to marine life in walruses and dolphins

how many antennae do crustaceans have?

two pairs of antennae

how can you differentiate krill and shrimp?

krill have 3 segments (head, thorax, abdomen) while shrimp have two (cephalothorax, abdomen), krill have exposed gills and 2 antenna, shrimp has 2 pairs of antennae

how do you identify zoea larva?

their sharp pointy spine used for defense. they are baby crustaceans

what is gastrulation?

in embryonic development, when a cell that has undergone cleavage begins to fold in on itself to make layers

explain the difference between protostomia and deuterostomia

if the blastopore (crevice from gastrulation) become the mouth, it is protostomia and if it becomes the anus it is deuterostomia

who has pentaradia symmetry and what is it?

5 part radial symmetry, the echnioderms (sea stars)

what are the four distinct characteristics of phylum chordata?

notochord, dorsal nerve cord (located above the notochord), pharyngeal slits, and a post-anal tail

what are salp and why do they matter?

planktonic tunicate —> salp blooms

what is the loose phylogenetic tree of chordata?

amphioxiformes most basal, then tunicata & vertebrates more derivated

what is the defining feature & common name of a hemichordate?

acorn worm, the buccal diverticulum = a rudimentary notochord

animals of & distinguishing feature of: porifera

sponges, choanocytes, filter feeders, asymmetric

animals of & distinguishing feature of: cnidaria

jellyfish, sea anenomes, corals, cnidocytes (nematocysts), predators, radial symmetry

animals of & distinguishing feature of: ctenophora

comb jellies, colloblasts & ciliary combs, predators, radial

animals of & distinguishing feature of: platyhelminthes

flatworms, flat bodies, breath through osmosis, parasitic, bilateral symmetry

animals of & distinguishing feature of: nermertea

ribbon worms, strong muscular body that can change shape quickly, proboscis = retractable tongue with venom, predator, bilateral symmetry

animals of & distinguishing feature of: chaetognatha

arrow worms, strong jaw, second most abundant, predator, bilateral symmetry

animals of & distinguishing feature of: annelida

polychaetes, segmentation, predators, bilateral symmetry

animals of & distinguishing feature of: mollusca

bivalves, cephalopods, chitons, radula (except bivalves, have siphons), mantle/mantle cavity, foot, bilateral symmetry

animals of & distinguishing feature of: arthropoda

horseshoe crab, crustaceans, sea spider, exoskeleton (molting), jointed legs, predators, bilateral symmetry

animals of & distinguishing feature of: bryozoans

bryozoans = moss animal, colonial, in a box, lophophores for feeding, filter feeder, bilateral symmetry

animals of & distinguishing feature of: phoronida

phoronids, lophophores, can retract, filter feeding, worm like, bilateral symmetry

animals of & distinguishing feature of: brachiopoda

brachiopods (lingula are edible), lophopores, also shelled but different symmetry than bivalves, lots of fossils, bilateral symmetry

animals of & distinguishing feature of: echniodermata

sea star, brittle star, sea urchin, sea cucumber, sea lily, pentaradial symmetry, tube feet, water vascular system, predator, bilateral symmetry (when young)

animals of & distinguishing feature of: hemichordata

acorn worm, buccal diverticulum, like a half of a notochord, bilateral symmetry

animals of & distinguishing feature of: chordata

tunicata, vertabrates, amphioxus, notochord, dorsal nerve cord (above notochord), pharyngeal slits, post anus tail, bilateral symmetry

what is one trait hydrozoa medusa have that scyphozoa medusa do not have?

a vellum = shelf of tissue extending in from bell to manubrium.

what color of light penetrates seawater best?

blue light

what six ions compose most of seawater?

Na, Cl, Mg, Ca, K, SO4

what is hypoxia?

a low oxygen area (dead zone)

what is LUCA?

last common ancestor

what is an osculum?

exit of water channel in the middle of a sponge

why are sponges ecologically important?

they host microbial communities (are holobionists)

what are placozoa?

simplest structure animal, opportunistic grazers

what is a nematocyst?

organelle that delivers sting within cnidocyte

what is body structure of cnidarian?

endoderm & ectoderm surround canal structure, mesoglea = gelatinous matrix, manubrium sticks out with the mouth, umbrella = top, tentacles

what are four groups of cnidarians?

scyphozoa, cubozoa, hydrozoa, anthozoa

what is special about cubozoa?

they have complex eyes and a relatively well developed nervous system

explain zooids

modules of colony all interconnected

what is a siphonophorae

colonial organism composed of medusoid & polypoid zooids

what are the differences between hexacorallia and octocorallia?

hexacorallia (six) are never polymorphic, octocorallia (eight) are polymophic

what are myxozoa?

parasitic cnidarians

what is the life cycle of a mollusc?

egg+sperm —> trochophore larva —> veliger larva —> metamorphosis —> juvenile —> adult

what are polyplacophora?

chitons —> eight overlapping plates, attached to hard surfaces

what are aplacophora?

shell-less molluscs covered in spicules (sharp needles)

what are monophlacophora?

single-shelled molluscs (UNCOILED) that are very rare, not GASTROPODS

what are scaphopoda?

tusk-shaped shells that are open at both ends with captacula (anterior feeding tentacles)

what are gastropoda and their characteristics?

snail & slug, coiled, univalve shell, distinct head, torsion

why are slugs polyphetic?

slug refers to lots of groups b/c shell-less ness has arisen lots of times b/c of convergent evolution (ex. nudibrach, sacoglossa, aplysia)

when does a bivalves shell form and with what part?

the umbo starts to form in the veliger larva stage

how do bivalves bury into the sand?

foot can change shape —> sharp to penetrate then expand to anchor pull down, sharp ventral side of shell to cut into sand

what is Shiu Hau Wan?

threatened mudflat/sandflat with bivalves and horseshoe crabs

what are chromatophores?

cells that allow cephalopods to change colors

what do lophotrochozoa demonstrate?

highly conserved early development, spiral cleavage, conserved cell fate

what are the main sections of an annelid?

segmented body: parapodia are feet on each segment, prostomium is front, pygidium is rear, peristomium is right behind prostomium, telobalstic growth is when grows from in front of pygidium

what are three types of annelids?

free-living, burrowing, tube-dwelling

what are lophophores?

ring of celiated tentacles surroundign the mouth used for suspension feeding

what is special about the brachiopod shell?

it has a pedicle where a fleshy foot extends from. extends from ventral side since ventral shell is bigger

what is an operculum?

the lid that closes the cystid (exoskeleton box) of a bryozoan

what are the exoskeletons of ecdysozoa made out of?

chitin because it is thinner & lighter

what do the compound eyes of arthropoda do?

poor image resolution, wide view angle, very fast movement

what is coagulogen?

clotting agent found in horseshoe crab blood that is used to test new drugs for bacteria

why are barnacles bad?

they are a fouling organism that attaches to boats and slows them down

what are the differences between amphipods & isopods?

amphipods (different feet, laterally compressed) vs isopods (same feet, dorsoventrally compressed)

what is a blastopore?

gap where cell folds in during gastrulation