Goff Zoology: Chapter 24 + 30: Fishes + Osmosis

Chondrosteans

Ray-finned fish charaterized by a cartilaginous skeleton and a lack of scales on most of their body

Teleost

Bony fish that includes all ray-finned fish. Has a movable upper jaw that allows them to protrude their mouths

Nonteleost neopterygians

Ray fish that is not part of the teleost group of fish. Have different skeletal structures or digestive systems

Oviparous

Eggs are laid externally (ex. Salmon)

Ovoviviparous

Eggs are kept in the body and hatch inside, but are not attached to the mother

Viviparous

Attached to the mother, embryos nourished by the placenta

Myxini

Hagfishes

Petromyzontida

Lampreys

Chondrichthyes

Cartilaginous fishes

Actinopterygii

Ray-finned bony fishes

Sarcopterygii

Lobe-finned bony fishes

Sharks

Chondrichthyes

Rays

Chondrichthyes

Chimaeras

Chondrichthyes

Lungfish

Sarcopterygii

Coelacanths

Sarcopterygii

Tetrapods

Sarcopterygii

Hypoosmotic

A marine fish that has body fluids with a lower concentration of salts than the surrounding sea water

Hyperosmotic

A freshwater fish that has higher salt concentration in its body fluids than the surrounding water

Osmotic Conformity

When body fluid concentration rises or falls with changes in the concentrations of seawater  

Osmotic Regulation

Maintaining a stable balance of water and salts within range of cellular function

Stenohaline

Animals that are restricted to living in a narrow salinity range. Oceanic invertebrates have very limited abilities to withstand osmotic change, and will die if they placed in water with dilute saltwater because they cannot handle dilution

Euryhaline

Animals that can survive a wide range of salinity changes

Hyperosmotic (hypertonic)

Maintaining body fluids more concentrated than the surrounding water

Hypoosmotic (hypotonic)

Maintaining body fluids less concentrated than the surrounding waters

Osmoconformers

Animals that are incapable of regulating osmotic pressure of their body fluid

Protonephridium

A type of nephridium found in organisms like flatworms and rotifers. Considered a closed system

Nephridium (metanephridium)

Invertebrate excretory organ that evolved to maintain appropriate osmotic balance. An open system

Vasopressin

the antidiuretic hormone, promotes water conservation by the kidney

Poikilothermy

Body temperature that fluctuates with environmental temperature

Homeothermy

Constant body temperature, regulated by the organism not the outside temperature

Ectothermy

Body temperature is determined by the outside environment

Endothermy

Body heat is maintained internally