You are here:

Biology/Antifreeze effects in icefish and humans


QUESTION: So in a book, i read that a species of Arctic fish, creatively called the Icefish can survive in very cold water, cold to the point where it would freeze most other fish. It can survive because it doesn't have red blood cells and has antifreeze (it harnesses O2 directly from the water). So my questions are:

1) Is not having red blood cells a prerequisite to having anti freeze; in other words, is anti freeze by nature harmful to blood cells?

2)If its not harmful, is there a biofriendly antifreeze that could be used in humans?

3) How does the icefish directly absorb oxygen? Would that also mean that if the icefish bled out, it could still survive without any blood in warm waters where needing antifreeze wouldnt be necessary?

PS if you dont know, please inquire about. a tall order, i know, but ive asked around and no one seems to know

ANSWER: Hi Hasnain
 These are truly remarkable. They can survive without Hemoglobin because they have a different circulatory system. Their heart is enlarged an so are are the blood vessels. They also have no scales and absorb oxygen through the skin
1. Do not confuse the fish antifreeze with antifreeze we use.  The "antifreeze" they have is a modified organic chemical that evolved from a protein called Trysinogin.  WE do not know about the effect of this compound on red cells because the compound had
s replaced the red cells
2. It is unlikely that it could be useful to humans
3. Oxygen is taken in through gills and the skin They could not survive without liquid carrying oxygen to the tissues

Google Channichthyidae to find out more

---------- FOLLOW-UP ----------

QUESTION: How does antifreeze work exactly? Is the liquid in the veins of the fish itself unfreezable? A bit unclear about the protein, please do tell. Explanation in small words would be preferred.

How does a protein evolve into anything other than a protein btw?

Assuming the skin is already permeable to oxygen, whats the purpose of gills? Is oxygen diffusion less efficient than absorption through gills, and is just a back up, maybe (this assumption comes from the fact that icefish need bigger veins and a bigger heart)

What is the liquid inside the veins? is the liquid itself antifreeze+ oxygen transfer, or are there cells or something that transfer the oxygen?

When its said that icefish can absorb O2, what exactly does it mean? Could you describe the process (again when you explain keep the vocab simple where possible)

What does it take for red blood cells to survive? Could they survive in a cup of tap water, or any kind of water?

Thanks. Sorry for the long question, but dont get comfortable, theres a lot more coming.

PS. please space out the answer when you type it (skip a line between answers please) Thank You

Allow me to go first to the antifreeze question. WE have to go back to elementary physics The most common for of energy is heat. There is no form of energy called cold. All warm bodies are always losing heat. A cup of hot water is losing heat and will do so until the temperature is the same as the environment around it. Temperature of water is measure of the molecular movement of water molecules. As the heat flows away the molecules grow closer together and the water becomes more dense this continues until  maximum density occurs and the water undergoes a physical change and becomes a solid (ice). This occurs when the water molecules bond together. Actually water has a strange quality in the the maximum density occurs at 4 degrees C. Then the density deceases and the icy being less dense floats
 As hat is carried away the attractive e force between water molecules increases. When an antifreeze is added to the water the extra molecules slow down the attraction decreasing the freezing point.
The situation within the body of a fish is governed by the same laws of physics because it is the water in the blood that we are concerned about Any thing added to water can lower the freezing point. Trypsinogin is a protein found in all fishes. During the evolutionary process it is changed chemically to lower freezing point.

I cannot get into this process with you without getting involved with the biochemistry.

The absorption of oxygen is minimal to the total amount needed by the fish The gills supply most O2 need

Liquid in the veins is mostly water. The proteins act as an antifreeze The Oxygen it transported by ted circulatory system and enters he cell by simple diffusion.

You asked about O2 absorption.  This is a different topic altogether and needs a lengthy discussion. I am giving you an assignment. Look up diffusion and tell me what you what you already know. I cannot do all of the work here

Red blood are not really cells sine they have no nucleus and in the body they have a short live span. They cannot survive out of the blood. Why? This also involve s diffusion

If you have a lot more question you will have to do some of the work.  I am a teacher and I do not do all of the work for the student.

Look up diffusion



All Answers

Answers by Expert:

Ask Experts


Walter Hintz


Science teacher for over 50 years. MSc. in biology. I can answer questions in general biology, zoology, botany, anatomy and physiology and biochemistry.


I have a MSc in biology and have been a science teacher for over 50 years. At present I am a faculty member at a college and a science consultant at seven catholic schools.

The Ohio journal of Science
Momentum-The Journal of the Catholic Education Association

©2017 All rights reserved.