Marine Biology and Invertebrate Zoology Vocabulary

A comprehensive vocabulary review of evolutionary concepts, marine ecological zones, developmental biology, and invertebrate morphology based on lecture notes.

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

Organisms with no membrane-enclosed organelles or nuclei, and no cytoskeleton.

Archaea

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

Protista

Organisms characterized in notes as having no membrane-enclosed organelles or nuclei; no cytoskeleton.

Fungi

Organisms with a chitinous wall around vegetative fungal cells.

Plantae

Unicellular or multicellular photosynthetic organisms.

Animalia

Multicellular, heterotrophic, tissue-layering eukaryotes.

Specific Heat

The amount of energy required to heat a substance.

Carbonate Buffering

Process where carbonate ions balance excess $CO_2$ content by re-speciating into bicarbonate 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

$0-1000\,\text{km}$ from shore, $< 200\,\text{m}$ deep, characterized by high biological productivity.

Continental edge

Rapid change in bathymetry; transition zone between shelf and slope.

Continental slope

Region with a slope of $4-6\%$, located $200-3000\,\text{m}$ deep.

Abyssal plain

Region with no light, $> 3000\,\text{m}$ deep, with productivity driven by chemosynthesis.

Supratidal

Area above mean high tide, flooded by storms.

Intertidal

Dynamic area between low and high tide.

Subtitle

Area below low tide line, never uncovered.

Neritic

Pelagic region over continental shelf.

Oceanic

Pelagic region over continental shelf and beyond.

Photic

Water column with enough sunlight for photosynthesis.

Aphotic

Water column with not enough sunlight for photosynthesis.

Disphotic

Transition region between photic and aphotic zones.

Reynolds number

A dimensionless term that describes 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 on sediment/substrate.

Biology

The study of life.

Zoology

The branch of biology that deals with animals and animal life.

Invertebrates

$97\%$ of the animals on the planet; animals without a vertebral column.

Prokaryote

Single-celled organism without a nucleus, mitochondria, or other membrane-bound organelles.

Metazoa

Ingestive, heterotrophic, sexual, multicellular eukaryotes that form tissues.

Ediacaran Period

$635-541\,\text{MYA}$; characterized by worldwide invertebrate fauna.

Cambrian Explosion

$541-520\,\text{MYA}$; rapid increase in biodiversity and abundance.

Stromatolites

Layers of microbial mats; bio-accretionary structures.

Primary endosymbiosis

$2.5-2\,\text{BYA}$; alphaproteobacteria symbiosis generates mitochondria, creating the first eukaryotic multicellular organisms.

Great Oxygenation

$2.5-2\,\text{BYA}$; 1st mass extinction where oxygenation grants atmospheric protection.

Paleozoic

$270\,\text{MYA}$; $\sim 90\%$ of species go extinct; marked by increased temperature and atmospheric $CO_2$, and decreased pH and $O_2$.

Adaptive radiation

Small-bodied 'generalist' survivors repopulating devastated environments.

Monophyletic

Groups / clades that include all descendants of a stem species.

Paraphyletic

Group that has the same evolutionary origin, but does not include all the descending groups.

Polyphyletic

Composite groupings of organisms without true biological rationale or shared biological ancestor.

Bernoulli's principle

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

Infaunal

Organisms that live within sediment.

Interstitial

Living between sand grains.

Meiofauna

Organisms living between sand grains.

Errant

Active, motile organism.

Sessile

Organism firmly attached to the substrate.

Sedentary

Unattached or weakly attached organism.

Holoplankton

Organisms that remain in plankton for their whole life.

Meroplankton

Organisms that are temporary members of the plankton community.

Choanocyte

Collar cell in sponges reminiscent of choanoflagellates.

Cilia

Shorter, more abundant cell structure for movement, feeding, and digestion.

Flagella

Longer, fewer cell structure for movement, digestion, gas exchange, and reproduction.

Oxygen diffusivity

Travels only $1\,\text{mm}$ 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 the initial division of a zygote.

Holoblastic

Cleavage planes pass completely through the cell.

Meroblastic

Cleavage planes do not pass completely through.

Macromeres

Larger cells at the vegetal pole.

Micromeres

Smaller cells at the 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 the environment.

Osmoconformer

Ion/water balance varies with the 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.

Metameres

Repeated sections in annelids.

Proglottids

Repeated sections of tapeworms.

Spicules

Structural support/defense for sponges.

Neoblast cells

Regeneration cells in platyhelminthes.

Crystalline style

Unique digestive structure found in bivalves and gastropods.

Parapodia

Appendage on the sides of many annelids.

Proboscis

Used to capture prey by nemerteans.

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

Free-swimming planktotrophic larvae.

Prostomium

1st anterior body segment.