Anything that causes injury to your fish and invertebrates will cause physical stress. This once again can lead to either immediate death or diseases.
Like other injured animal, when fish is injured they bleed when their tissues are damaged. When the fish is in some way bitten, dropped or physically abused, their veins and arteries carrying blood throughout their body will be damaged.
Bleeding can be external or internal. It depends on the nature and the extent of the damage.
I have mentioned that fish has a protective mucous layer on their skin.
If a fish is hurt physically, it will compromise the mucous layer and can lead to infection.
It can also cause immediate death from blood loss.
Remember that an injured fish is not a healthy fish. It may stop feeding. Their immune system may also become compromised. All these can lead to a more serious ailment.
Handling stress obviously will cause physical damage. But there are still a couple more conditions to watch out for like:
- Other social behaviors