Fish Physiology

Oxygen

A chemical element essential for producing energy to support metabolic needs.

Metabolism

The sum of all biochemical processes occurring within an organism.

Countercurrent Gas Exchange

A system where blood and water flow in opposite directions to maximize oxygen exchange.

Facultative air-breathing

The ability to supplement gill respiration with air breathing when necessary.

Obligate air breathing

An air breathing requirement; fish must have access to air or risk drowning.

Ectotherms

Organisms that rely on external sources to regulate their body temperature.

Homeostasis

The regulation of an internal environment to maintain stable conditions.

Osmoregulation

The control of internal water and ion concentrations in organisms.

Physostomous condition

Gas bladder connected to the gut, allowing for gas exchange.

Physoclistous condition

A gas bladder that is sealed, with no direct connection to the gut.

Nitrogenous waste

Waste products containing nitrogen, such as urea, excreted by aquatic organisms.

Ionoregulatory cells

Cells in gills that regulate the uptake of ions such as sodium and chloride.

Buoyancy regulation

The ability of fish to maintain control over their position in water based on gas bladder adjustments.

Ampullae of Lorenzini

Electroreceptor organs in certain fishes that detect low frequency electric fields.

Gills

Efficient respiratory organs in aquatic animals that extract oxygen from water.

Osmoconformers

Organisms whose internal osmotic concentration matches that of their environment.

Heterocercal tail

An asymmetrical tail structure in some fishes providing lift and thrust.

Homocercal tail

A symmetrical tail structure allowing for efficient horizontal swimming motion.

RAM ventilation

A method of breathing in fish by swimming with the mouth open to move water over the gills.

Energy budget

Calculation of how consumed energy is allocated for activities, growth, and reproduction.

Chemoreception

The ability to detect chemical stimuli in the environment, used for finding food or communication.

Cutaneous respiration

Gas exchange through the skin, primarily seen in smaller fish.

Olfaction

The sense of smell, used by fish to detect various chemical cues in the water.

Electroreception

The ability of some fish to detect electric fields in their environment.

Fusiform body

A streamlined body shape that reduces drag and enhances swimming efficiency.

Swimming muscles

Muscles that provide propulsion and maneuverability in fish locomotion.

Anadromous species

Fish that migrate from saltwater to freshwater to spawn.

Endocrine system

The system that releases hormones to regulate bodily functions, including metabolism and osmoregulation.

Skeletal adaptations

Changes in bone structure in fish that affect swimming efficiency and buoyancy.

Pectoral fins

Fins located on the sides of fish, used for maneuverability and stabilization.

Caudal fin

The tail fin of a fish, critical for propulsion and steering during swimming.

Hydrostatic pressure

Pressure exerted by fluids that can affect locomotion in aquatic organisms.

Elastic energy

Energy stored in stretched or compressed materials, used in swimming dynamics.

Lateral line system

A sensory system in fish that detects water movements and vibrations.

Gustation

Taste sensation; fish use gustation primarily for recognizing food.

Dorsal fin

The fin located on the top of fish, important for stability during swimming.

Hyperosmotic

Organisms that are saltier than their surrounding environment, which affects their water balance.

Niche diversification

The process through which species evolve to exploit different resources in an ecosystem.

Electrolocation

The ability of certain fish to locate objects based on the electric fields they produce.

Energetic costs

The energy expenditure necessary for survival, growth, and reproduction.

Secondary lamellae

Thin membranes in fish gills that increase the surface area available for oxygen uptake.

Tropical fishes

A diverse group of fishes adapted to warm waters and various ecological niches.

Swimming efficiency

The ability of fish to use energy effectively while moving through water.

Aquatic air breathers

Fish that can exchange gases with both gills and lungs/air-breathing organs.

Streamlined body shape

A body design that minimizes resistance, aiding in efficient movement through water.

Euryhaline fishes

Fishes capable of living in a wide range of salinities.

Ion transport

Movement of ions across cell membranes, essential for osmoregulation.

Gas bladder

An internal gas-filled organ that helps fish maintain buoyancy.

Mechanical pressure

Force exerted per unit area, important for the functionality of body systems in fish.

Hormonal regulation

The control of physiological processes by hormones in the endocrine system.

Catfish adaptations

Modifications that allow catfish to thrive in various aquatic environments.

Homeostatic mechanisms

Biological processes that maintain stability in the internal environment of organisms.

Nutritional ecology

The study of how dietary intake affects the ecology and evolution of organisms.

Respiratory surfaces

Areas in aquatic animals where gas exchange occurs.

Swim bladder evolution

The biological changes in gas bladders that enhance buoyancy and breathing in fishes.

Amphibious breathing

The capability of some fishes to breathe both in water and air.

Nervous system accessories

Sensory structures that aid the nervous system in receiving and processing environmental stimuli.

Oxygen solubility

The amount of oxygen that can dissolve in water, influenced by temperature and salinity.

Thermal adaptation

Physiological changes in response to varying temperature conditions.

Fish locomotion

The various methods and adaptations that enable fish to move efficiently through water.

Nitrogen waste storage

The ability of some fish to convert and store nitrogenous waste in less harmful forms.

Feeding adaptations

Changes in morphology and physiology that enhance feeding efficiency in fishes.

Locomotory efficiency

The ability of fish to swim effectively using the least amount of energy.

Chemical stimuli

Chemical signals in the environment that fish detect for various biological purposes.

Aquatic respiration techniques

Different methods employed by aquatic organisms to extract oxygen from water.

Physical adaptations

Morphological changes that aid in survival and reproduction in specific environments.

Neuroendocrine dysregulation

Disturbances in hormone regulation affecting neurological functions.

Environmental factors

Conditions in the surroundings that impact physiological processes in organisms.

Mobility in aquatic environments

The capacity of aquatic organisms to move efficiently in their habitats.

Pressure gradients

Differential pressures that can influence fluid dynamics within an organism.

Upper-jaw mobility

Increased movement of the upper jaw contributing to diverse feeding strategies.

Evolutionary adaptations

Changes in species over time to improve survival and reproduction in given environments.

Hydraulic skeletons

Structures that utilize fluid pressure for support and movement in soft-bodied organisms.

Shrinking habitats

Decreasing environments available for species, particularly due to human impact.

Benthic adaptations

Morphological characteristics of fish that allow them to live on the bottom of water bodies.

Lungfish adaptations

Specialized features that allow lungfishes to survive in low-oxygen environments.

Hydrodynamics

The study of fluids in motion, particularly important for swimming efficiency in fish.

Physiological maintenance

The processes that organisms undergo to sustain their internal conditions.

Nitrogen cycling

The processes involved in the transformation and movement of nitrogen in ecosystems.

Physiological responses

Reactions of organisms to environmental changes affecting their homeostatic balance.