Subtidal Environments and Marine Adaptations

Vocabulary flashcards generated from lecture notes on subtidal environments and marine adaptations, covering organism classifications, body forms, feeding styles, and coloration.

Subtidal Environment

The area located below the low tide level.

Benthos

Organisms that live on or in the seafloor.

benthic

Pertaining to the seafloor.

Nekton

Organisms that are swimmers and can swim against a current.

Demersal

Organisms that can swim but prefer to lay on the bottom (example: flounder).

substrate

The surface upon which an organism grows (e.g., the bottom, a dock piling, rock).

pelagic

Pertaining to the waters of the ocean, as opposed to the bottom.

niche

The lifestyle or role an organism plays in an ecosystem.

competitive exclusion

The concept that more than one species cannot occupy exactly the same niche; one always outcompetes the other.

segmentation

Divided into similar sections (like an earthworm).

cilia

Hair-like projections used for locomotion.

photophore

A light-producing cell; used in bioluminescence.

Inferior & Subterminal Mouth Placement

Indicates an organism is a bottom feeder.

Terminal Mouth Placement

Indicates an organism eats prey located directly in front of it.

Superior Mouth Placement

Indicates an organism eats prey located above it.

Streamlined Body Shape

An adaptation for fast movement (example: tuna).

Flat Bellied / Horizontal Disk Body Shape

An adaptation for lying on the bottom (example: flounder).

Eel-like Body Shape

An adaptation for living in narrow spaces.

Caudal Fin (Tail)

Provides swimming ability; in sharks, it provides lift because they lack a swim bladder.

Radial Symmetry

An organism displays many lines of symmetry (examples: sea anemone, jellyfish).

Bilateral Symmetry

An organism displays one line of symmetry (examples: lobsters, clams, crabs).

Pentamerous Symmetry (Pentaradial)

An organism is divided into five identical sections (examples: starfish, sea urchins).

Countershading

A body coloration adaptation where an organism has a light belly (blends with surface when viewed from below) and a dark top (blends with bottom waters when viewed from above).

Mottled Body Color

A body coloration adaptation that helps an organism blend into rocks or the bottom.

Poster (Warning) Coloration

Bright patches on an organism's body to advertise its presence, often signaling toxicity or danger.

Bioluminescence

The production of light by living organisms, often using photophores (light organs), utilized for mating, attracting prey, scaring predators, or countershading.

Linnaean Classification

A hierarchical system for classifying organisms: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

Porifera

A phylum including sponges; characterized by tiny pores for water intake, filter feeding, and lack of symmetry.

Arthropods

A phylum characterized by segmented bodies and jointed appendages.

Mollusca

A phylum including octopuses, clams, and squids; characterized by soft, un-segmented bodies, typically with an internal or external shell or a mantle.

Annelida

A phylum including segmented worms (example: Glycera blood worm).

Echinodermata

A phylum including starfish and sea urchins, often characterized by pentamerous symmetry.

Cnidaria

A phylum including sea anemones and jellyfish, typically displaying radial symmetry.

Hydrodynamic

reduces drag

Denticales

The specific type of scales that form a shark's rough skin