Marine Biology Chapter 8-11, 15 Vocab

Dioecious

Describes a species in which individuals are either male or female, each producing only one type of gamete.

Hermaphroditic

Describes an organism that has both male and female reproductive organs and can produce both types of gametes.

Hypoosmotic

Having a lower concentration of solutes compared to the surrounding environment, leading to water moving out of the organism.

Hyperosmotic

Having a higher concentration of solutes compared to the surrounding environment, causing water to move into the organism.

Isosmotic

Having the same concentration of solutes as the surrounding environment, resulting in no net movement of water.

Osmoconformer

An organism that maintains an internal environment that is isosmotic to its surroundings, matching its body's solute concentration to that of the external environment.

Osmoregulator

An organism that actively regulates its internal solute concentration, maintaining it regardless of external environmental conditions.

Gills

Respiratory organs found in aquatic animals, which extract oxygen from water and expel carbon dioxide.

Notochord

A flexible, rod-shaped structure found in embryonic stages of all chordates, providing support and later replaced by the vertebral column in vertebrates.

Limiting factor

A condition or resource that restricts the growth, distribution, or abundance of an organism or population, such as food, water, or temperature.

Synapomorphy

A shared, derived trait or characteristic that is unique to a particular evolutionary group, providing evidence of common ancestry.

Countershading

A form of camouflage in which an animal's coloration is darker on its upper side and lighter on its underside.

Thermoregulation

The process by which an organism regulates its body temperature, keeping it within a certain range despite external temperature fluctuations.

Counter-current heat exchanger

A physiological adaptation where warm and cold blood flow in opposite directions in close proximity, allowing heat to be transferred between them.

Pinniped

A group of marine mammals that includes seals, sea lions, and walruses, characterized by their fin-like limbs.

Sexual dimorphism

Differences in size, appearance, or behavior between males and females of the same species.

Sirenian

An order of fully aquatic, herbivorous mammals that includes manatees and dugongs.

Cetacean

An order of marine mammals that includes whales, dolphins, and porpoises.

Baleen

A filter-feeding system found in the mouths of certain whales, consisting of flexible, hair-like structures.

Mysticete

A suborder of cetaceans, known as baleen whales, that filter-feed using baleen plates.

Odontocete

A suborder of cetaceans, known as toothed whales, that includes dolphins and porpoises.

Apneustic breathing

A pattern of breathing where an animal takes deep breaths followed by long periods of holding its breath.

Vasoconstriction

The narrowing of blood vessels, which reduces blood flow to certain body parts.

Bradycardia

A decrease in heart rate, often occurring in marine mammals during deep dives.

Echolocation

A sensory system used by certain animals to locate objects by emitting sounds and interpreting the returning echoes.

Melon

A fatty organ in the heads of toothed whales that focuses and directs sound waves during echolocation.

Pod

A social group of cetaceans that travel and live together.

Blubber

A thick layer of fat beneath the skin of marine mammals that provides insulation and energy storage.

Poikilotherm

An organism whose body temperature varies with the temperature of its surrounding environment.

Homeotherm

An organism that maintains a stable internal body temperature regardless of external environmental changes.

Ectotherm

An organism that relies on external environmental heat sources to regulate its body temperature.

Endotherm

An organism that generates heat internally to maintain its body temperature.

Estuary

A coastal water body where freshwater from rivers mixes with saltwater from the ocean.

Coastal Plain Estuary

An estuary formed when rising sea levels flood river valleys.

Bar-Built Estuary

An estuary created by the accumulation of sandbars or barrier islands.

Fjord

A deep, glacially carved estuary with steep sides and a U-shaped cross-section.

Tectonic Estuary

An estuary formed when tectonic activity causes land to subside and fill with seawater.

Well-Mixed Estuary

An estuary with uniform salinity throughout its depth due to strong mixing.

Stratified Estuary

An estuary where freshwater and saltwater form distinct layers due to minimal mixing.

Brackish

Water that has a mix of freshwater and saltwater.

Stenohaline

Organisms that can tolerate only a narrow range of salinities.

Euryhaline

Organisms that can tolerate a wide range of salinities.

Partial Osmotic Conformer

An organism that partially adjusts its internal osmotic pressure to match its environment.

Sediment

Particles of soil, sand, and organic material that settle to the bottom of a water body.

Channel

The main passageway through which water flows in a river, estuary, or similar system.

Salt Marsh

Coastal wetlands flooded and drained by saltwater, dominated by salt-tolerant plants.

Mudflat

Coastal wetlands with fine sediments, exposed during low tide.

Detritus

Dead organic material that serves as a food source for many organisms.

Oxygen-depleting Pollutant

Substances that lead to reduced oxygen levels in water.

Toxic Pollutant

Chemicals harmful to living organisms, such as heavy metals or pesticides.

Dead Zone

An area in a water body with very low oxygen levels.

Chitin

A polysaccharide that forms the exoskeletons of arthropods.

Chiton

A marine mollusk with a shell made of eight overlapping plates.

Salt Wedge

A distinct layer of saltwater underneath freshwater in a stratified estuary.

Osmoregulation

The process by which organisms regulate their internal salt and water balance.

Isosmotic

A condition where the internal osmotic pressure of an organism is equal to that of its environment.

Hyperosmotic

An organism with a higher internal osmotic pressure than its surrounding environment.

Hypoosmotic

An organism with a lower internal osmotic pressure than its surrounding environment.

Nutrients

Essential substances that provide energy or building blocks for living organisms.

Infauna

Animals that live buried within the sediments of a seabed or riverbed.

Epifauna

Animals that live on the surface of the seabed or attached to submerged objects.

Suspension Feeding

A feeding strategy where organisms filter particles from the water.

Grazing

A feeding strategy where organisms consume plants, algae, or microorganisms from surfaces.

Broadcast Spawning

A reproductive strategy where eggs and sperm are released into the water for external fertilization.

Larval Dispersal

The movement and spread of larval stages of organisms through water currents.

Intertidal Zones

Areas of the shore exposed to air at low tide and submerged at high tide.

Rocky Shores

Coastal areas with solid rock substrates, home to diverse organisms.

Sandy Shores

Coastal areas dominated by sand, with dynamic and shifting habitats.

Upper Intertidal

The highest zone of the intertidal area, rarely submerged.

Desiccation

The loss of moisture from an organism or substrate.

Competition

The struggle among organisms for limited resources.

Middle Intertidal

The zone regularly submerged and exposed, subject to high competition.

Disturbance

Events that disrupt ecosystems or habitats.

Lower Intertidal

The zone that is rarely exposed and mostly submerged.

Subtidal

The area below the low tide mark that remains submerged.

Vertical Zonation

The distribution of organisms in distinct horizontal bands across the intertidal zone.

Bioaccumulation

The process by which a substance builds up in an organism over time.

Biomagnification

The increase in concentration of a substance as it moves up the food chain.

Keystone Species

A species that has a large impact on its ecosystem relative to its abundance.

Trophic Cascade

A series of changes triggered by the addition or removal of a top predator.

Simultaneous Hermaphrodite

An organism that possesses both male and female reproductive organs at the same time.

Sequential Hermaphrodite

An organism that changes sex during its lifetime.

Corallite

The calcium carbonate skeletal cup secreted by a coral polyp.

Cenosarc Tissue

The thin tissue that connects coral polyps within a coral colony.

Polyp

The sessile, cylindrical stage of a cnidarian's life cycle.

Medusae

The free-swimming, umbrella-shaped stage of a cnidarian's life cycle.

Zooxanthellae

Symbiotic algae that live within corals, providing nutrients.

Mutualism

A symbiotic relationship where both species benefit from the interaction.

Shelf Reef

A coral reef that forms along the continental shelf.

Oceanic Reef

A coral reef located in open ocean waters.

Atoll

A ring-shaped coral reef that surrounds a lagoon.

Fringe Reef

A coral reef that forms close to the shoreline.

Barrier Reef

A coral reef separated from the shoreline by a lagoon.

Fragmentation (Asexual Reproduction)

A form of reproduction where parts of a coral colony break off and grow into new colonies.

Planula Larvae

The free-swimming, ciliated larvae of corals.

Coral Bleaching

The loss of zooxanthellae from coral tissues due to stress, leading to a white appearance.

Pavement

The hard, flat surfaces of the seabed associated with coral reef areas.

Reef

A submerged structure formed by the accumulation of coral skeletons.