Marine Biology Test 1 — Complete Review

These flashcards cover essential vocabulary related to marine biology, emphasizing Cnidarians, coral reefs, deep sea organisms, and their ecological significance.

Cnidocyte

Specialized cell in Cnidarians that produces and fires nematocysts.

Nematocyst

A stinging or adhesive thread fired from a cnidocyte, used to capture prey.

Radial symmetry

Body arrangement around a central axis, allowing detection of prey from any direction.

Polyp

A cylindrical body form of Cnidarians that is benthic or attached, with the mouth facing upward.

Medusa

A bell-shaped, free-swimming jellyfish form of Cnidarians, with the mouth pointing down.

Gastrovascular cavity

A digestive cavity with a single opening functioning in both digestion and gas exchange.

Zooxanthellae

Photosynthetic dinoflagellates that live symbiotically in coral tissues, providing nutrients.

Hydrozoa

Class of Cnidarians that includes both polyp and medusa forms, often colonial.

Scyphozoa

Class of Cnidarians where the medusa is the dominant form, includes true jellyfish.

Cubozoa

Class of Cnidarians characterized by box-shaped bells and complex eyes; includes highly venomous species.

Anthozoa

Class of Cnidarians that exists only in polyp form, such as sea anemones and stony corals.

Hermatypic coral

Reef-building corals that have symbiotic zooxanthellae and deposit calcium carbonate.

Ahermatypic coral

Non-reef-building corals that lack zooxanthellae, can survive in deeper or colder waters.

Coral bleaching

Process where stressed corals expel zooxanthellae, becoming transparent and revealing their white skeleton.

Ocean acidification

The decrease in pH of the ocean due to increased CO2 absorption, affecting calcifying organisms.

Chemosynthesis

Process by which some organisms, like those at hydrothermal vents, convert chemical energy (H2S) into organic matter.

Bioluminescence

The production and emission of light by living organisms, used for luring prey, communication, and camouflage.

Vertical migration

The daily movement of organisms between surface waters at night and deeper waters during the day to avoid predators.

Hydrothermal vent

An opening in the ocean floor that emits superheated water, supporting unique ecosystems reliant on chemosynthesis.

Deep Sea

The part of the ocean below 1000 meters that is dark, cold, and characterized by high pressure and scarce food.