People have actually verified it from what I have read about bringing fish out of hawaii.
Here is what TSA wrote to a person on another site. As I said it is up to the particular TSA agent, but it is allowable.
"As an FYI, I wanted to bring some fish back from Hawaii to CA. I e-mailed TSA, and this is the response I received is below. Bear in mind, the airlines themselves don't check what you have in your carry-on, only TSA does during the screening.
Thank you for your e-mail regarding the Transportation Security Administration's (TSA) policy for carrying live fish onboard a commercial airline.
Travelers passing through security checkpoints may carry liquids, gels, and aerosols if these are in containers 3.4 ounces or smaller. All of these must be placed in one, quart-size, clear plastic, resealable bag and must fit comfortably in the bag (3-1-1 rule).
There is an exception to the 3-1-1 rule for live fish. If the fish is alive and swimming in the liquid, then the liquid is not an explosive. In addition, the container holding live fish may be larger than 3.4 ounces. The fish must be swimming in water that is contained in a clear, plastic container that is spill proof. This will allow the Transportation Security Officer to visually inspect the fish at the screening checkpoint.
However, regardless of whether an item is on the prohibited or permitted items list, the Transportation Security Officers have discretion to prohibit an individual from carrying an item through the screening checkpoint or onboard an aircraft. Therefore, Transportation Security Administration (TSA) security screening personnel make the final decision on whether to permit items like live fish into the secured area of the airport.
Also, TSA recommends travelers contact their airlines to inquire about any additional guidelines the airlines may have regarding traveling with live fish. For the most current information on TSA security screening procedures, visit our website at www.tsa.gov.
We hope this information is helpful.
TSA Contact Center "