Living in Water (Chapter 4)

Density

Viscosity

Heat Capacity

Heat Conductivity

Oxygen Content

Velocity of Sound

Refractive Index

Primary lamellae

Deoxygenated blood comes from the gill arch and travels through here to the secondary

Operculum

Icreases pressure to pull water in to go over the gills

Obtain oxygen

What is the purpose of gills?

One way flow

How is the flow of water in the gills?

Gill Rakers

Point inwards in gills, form a filter, and guide food down into the digestive tract, block it from coming out of the gills. The finer these are, the smaller the gaps will be.

Secondary lamellae

Where the gas exchange of the gills takes place, blood passes through here and becomes oxygenated then flows back into the gill arch

Afferent and efferent lamellar

The arteries that move blood in the lamellae of the gills

Countercurrent

Which way does blood flow in the lamellae?

Countercurrent Exchanger

Allows for diffusion across the entire gill, prevents blood oxygen from equalizing with water oxygen

Buccal Pumping

Water enters the mouth; the mouth closes, volume decreases, pressure increases, and water is forced out over the gills. The operculum increases pressure and pulls water into the gills at the same time.

Ram Ventilation

Swimming through water with mouth open - brings water in to go over the gills

Facultative

Air breathers that can either breathe from water or from air, don’t have to have access to the surface

Obligate

Air breather that has to have access to the surface because it HAS to breathe air

Swim Bladders

Used for buoyancy, organ that keeps a bubble of gas in the body and keeps fish in the water column they want

Physostomous

Swim bladders that maintain connection to digestive tract, swallow oxygen and add it to bladder, or burp it up to control buoyancy

Physoclistous

Swim bladders with no connection to the digestive tract, have blood vessels that bring and take away gas from bladder

Gas gland

Part of gas bladder that releases lactic acid and decreases the pH, making hemoglobin let go of the oxygen, so now the oxygen is in the blood plasma

Ovale

Where gas exits the gas bladder in physoclistrous fish. Has sphincter muscles that open and close to release oxygen

Bohr Effect

In the presence of acid (low pH) you reduce the ability of hemoglobin to bind to oxygen

Root Effect

In the presence of acid (low pH), hemoglobin will release oxygen and have a lower saturation level

Rete mirabile

The network of blood vessels attached to the gas gland. Blood is recycled through and builds up oxygen in it until there is so much that it pushes into the gas bladder

Cartilagenous Fishes

Chondricthians without swim bladders, have large fatty livers for buoyancy, retain urea in bodies

Lateral Line System

Detects flow of water

Neuromast Cells

Sensory cells of the lateral line system

Kinocilia

Long hairs in lateral line system

Stereocilia

Short hairs in lateral line system

Killifish

Eat insects that drop on the surface of the water, use neuromast cells lining hteir head to detect them

Schooling Fish

Neuromast cells go along length of the body to detect fish around them

Electroreception

Aquatic organisms can perceive electricity in water

Ampullae of Lorenzini

Pores with electro-conductive gel and a nonconductive wall, so signal gets drawn through gel and into receptors

South American Electric Eel

Has 10,000 layers of electric cells (=600 volts) throughout the length of its body (except head). The longer it is, the bigger of a charge you can get

Electrocyte

Specialized electric muscle cell that’s been modified in an electric organism - sodium enters potassium channels and activates it, making it electric, and it goes away once the sodium decreases

Electric Discharge

Electrocytes are lined up next to each other in the organism and are positive inside/out when resting, but when active, they’re negative on the outside of the cells and positive inside so that the current can flow between them

Weakly Electric Fish

Fish that use electricity to move around, find prey, communicate, etc.

Strongly electric fish

FIsh that use electricity to hunt prey and defend themselves