Midterm: Biology of Marine Invertebrates

Biology

the study of life

zoology

the branch of biology that deals with animals and animal life

Prokaryote

single celled organism without a nucleus, mitochondria, or other membrane bound organelles

Metazoa

ingestive, heterotrophic, sexual, multicellular eukaryotes that form tissues

Ediacaran Period

worldwide invertebrate fauna; 635-541 MYA

Cambrian Explosion

541-520 MYA, rapid increase in biodiversity and abundance

Stromatolites

layers of microbial mats, bio-accretionary structures

Primary endosymbiosis

2.5-2 BYA, alphaproteobacteria symbiosis generates mitochondria, first eukaryotic multicellular

Great oxygenation

2.5-2 BYA, 1st mass extinction, oxygenation grants atmospheric protection

Paleozoic

270 MYA, ~90% of species go extinct, increased: temperature atmospheric CO2, decreased: pH, O2

Adaptive radiation

small bodied generalist survivors repopulating devasted environments

Monophyletic

groups/clades that include all descendants of a stem species

Paraphyletic

group that has the same evolutionary orgin, but does not include all the descending groups

polyphyletic

composite groupings of organisms without true biological rationale/ shared biological ancestors

Apomorphy

an evolutionary innovation present in a biological lineage but not with its ancestral group

Synapomorphy

shared apomorphy with 2 or more groups of organisms

Bacteria

No membrane enclosed organelles or nuclei; no cytoskeleton

Archaea

Anaerobic and aerobic, methane-producing organisms, no membrane enclosed organelles or nuclei, no cytoskeleton

Protista

no membrane enclosed organelles or nuclei; no cytoskeleton

Fungi

chitinous wall around vegetative fungal cells

Plantae

unicellular, multicellular; photosynthetic

Animalia

multicellular, heterotrophic, tissue layering eukaryotes

Specific heat

the amount of energy required to heat a substance

carbonate buffering

carbonate ions balance excess CO2 content by re-speciating into biocarbonate and carbonic acid

Niche

a set of all the conditions of a single species in a certain environment

Fundamental niche

complete range of environmental conditions where a species could survive, grow, and reproduce

realized niche

actual range of environments used by a species, part of the fundamental niche

Niche partitioning

similar species evolve to use different resources or inhabit different parts within the same environment

Continental shelf

0-1000 km from shore, < 200 m deep, high biological productivity

Continental edge

rapid change in bathymetry, transition zone between shelf and slope

Continental slope

region with slope of 4-6%, 200-3000 m deep

Abyssal plain

region with no light, > 3000 m deep, productivity by chemosynthesis.

Supratidal

area above mean high tide, flooded by storms

Intertidal

dynamic area between low and high tide

Subtidal

area below low tide line, never uncovered by the tide

Neritic

pelagic region over the continental shelf

Oceanic

pelagic region over the continental shelf and beyond

Photic

water column with enough sunlight for photosynthesis

Aphotic

water column with not enough sunlight for photosythesis

Disphotic

transition region between photic and aphotic zones

Bernoulli's principle

as the speed of a moving fluid (liquid or gas) increases, its internal pressure decreases

Reynolds number

a dimensionless term that describes the fluid flow patterns in different physical situations; the ratio of inertial to viscous forces acting on an object within a fluid

Epifaunal

organisms that live on top of sediment/substrate

Infaunal

organisms that live within sediment

Interstitial

living between sand grains

Meiofauna

organisms living between sand grains

Errant

active, motile organisms

Sessile

organism firmly attached to the substrate

Sedentary

unattached/ weakly attached organism

Holoplankton

organism that remain in plankton for their whole life

Meroplankton

organisms that are temporary members of the plankton community

Choanocyte

collar cell in sponge reminiscent of choanflagellate

Cilia

shorter more abundant cell structures for movement, feeding, digestion

Flagella

longer, fewer cell structure for movement, digestion, gas exchange, reproduction

Oxygen diffusivity

only 1 mm into tissues until fully utilized

Solutions to diffusion

fold cell surface, flatten, become thread-like, or become multicellular

Embryogenesis

the growth and development of an embryo

Vitellogenesis

yolk production

Zygote

fertilized egg

Blastomeres

cells resulting from initial division of zygote

Holoblastic

cleavage planes pass completely through cell; blastomeres are fully separated by thin membranes

Meroblastic

clevage planes do not pass completely through; blastomeres do not separate

Macromeres

larger cells at vegetal pole

Micromeres

smaller cells at animal pole

Radial cleavage

longitudinal and transverse divisions arrange blastomeres in rows

Spiral cleavage

successive diagonal division of cells

Blastula

embryonic stage of formation preceding embryonic germ

Blastocoel

space within the blastula/primary body cavity

Coeloblastula

hollow ball of cells, usually 1 cell layer thick

Steroblastula

solid ball of blastomeres

Discoblastula

cap of cells at the animal pole

Coelom

true body cavity

Protostome

mouth formed first during gastrulation

Deuterostome

anus formed first during gastrulation

Ectoderm

outer layer

Mesoderm

middle layer

Endoderm

inner layer

Osmoregulator

maintains ion/water balance independent of environment

Osmoconformer

ion/water balance varies with environment

Protogynous hermaphrodite

female transition to male

Protoandrous hermaphrodite

male transition to female

Propioceptor

senses orientation to environment

Geoceptor

detects the pull of gravity

Gonochoristic

having only testes or ovaries

Gastrula

embryonic stage where germ/tissue layers develop

Monophyletic

Groups/clades that include all descendants of a stem species

Metameres

repeated sections in annelid

Proglottids

repeated sections of tapeworms

Spicules

structural support/defense for sponges

Neoblast cells

regeneration cells in platyhelminthes

Crystalline style

unique digestive structure in bivalves and gastropods

Parapodia

appendage on the sides of many annelids

Proboscis

used to capture prey by nemertean

Retractor muscle

retracts proboscis

Mesenchyme

loosely organized mesodermal tissue

Peristaltic waves/ undulatory swimming

movement of larger worms

Stylets

nail shaped structures made of calcium phosphate

Cerebral ganglion

longitudinal nerve cords, encircles gut or proboscis (nemertean)

Pilidium larvae

free swimming planktotrophic larvae

Prostomium

1st anterior body segment