How can they be sure that it was thermic shock? Was there an autopsy? Where are the Autopsy results?
Lol how could you ascertain that a fish died from thermic shock by doing an autopsy?? Unless you are a trained veternarian, there would be no way to tell from an autopsy. It's not like cysts form or organs explode due to a change in temperature, it's all part of the nervous system which a normal person can't examine and make a true conclusion.
however, it could rule out other possibilities giving more validity to the statement that it was the thermic shock that did indeed kill the fish.
it is also possible for people other than vets to perform an autopsy on a fish. the following is an exert from a course guideline written by Dr. Erik L. Johnson, Veterinarian and Fish Health Specialist
How do you open the fish?
1) Lay the fish on its left side, with the head pointing to your right. Its belly should be facing you.
2) The first cut exposes the gills. Cut from the ventral midline of the fish between the gill covers [opercula], up to the eye and back to the top of the gill cover. The operculum is removed and the gills are plainly visible.
3) Examine and record gill condition. The gills should be smooth and beet red.
4) The second cut begins to open the abdomen. Cut from the anal pore (vent) forward on the midline to the boney junction between the pectoral fins.
5) Be as careful as you can not to cut too deeply or you may stir or disturb the internal organs, which could make the proper diagnosis difficult.
6) Cut upward from slightly in front of the pectoral fins but behind the head to the highest point you can before you hit the thick, dorsal musculature. Angle the scissors to the left when this resistance is met, and cut back across the body towards the tail, staying as "high up" on the side of the fish as you can to reveal the widest possible window on the organs. Bring this cut to its conclusion at the vent again. A substantial oval-shaped filet of fish is removed and the internal organs come into view.
What can you learn when the fish is opened?
ORGAN or TISSUE Gross (Obvious) Condition Interpretation
Eggs Abundant, distending the fish, no reserve fat in the abdomen with the eggs Egg impaction
Eggs Eggs are brown or tan and have coalesced into a solid, almost rubbery form. Egg impaction > Attempted egg re-absorbtion
Fat Absent Advanced inanition (starvation) or wasting
Fat Abundant almost to the exclusion of other internal organs Feeding a cheaply formulated food, excess energy and amino acids are being burned off and ingested energy is converted to adipose tissue.
Tumors Presence of any tumor is pathological and these can be fixed in Formalin and sent to a pathology lab for evaluation if the fish was fresh killed before the autopsy. We have necropsied and recovered tumors of the:KidneyOvaryTestesStomachBody wall Intestine
Intestines, body wall liver, kidney and air bladder. Blood splotches Bacterial infection which has progressed to a systemic or septic nature. Clotting disorders secondary to nutritional deficiencies.
Intestines Full of pus Bacterial infection, sometimes secondary to severe cold shock or feeding food in extremely cold water.
Intestines Ova or eggs of parasitic nematodes in the intestines Remaining fish can be dewormed with Levamisole with ease.
Liver Yellow Fatty Liver: Feeding a cheaply formulated food, excess energy and amino acids are being burned off and ingested energy is converted to adipose tissue.
Liver Pale with blood splotches Fatty liver with secondary opportunistic infection.
Gall bladder Large and green This suggests the fish was not eating in the days to weeks prior to necropsy. The gall bladders will typically empty out when the fish is eating well.
Kidney Swollen and gelatinous Renal cancer.
Kidney Swollen and bloody Bacterial infection has accessed the blood stream and has attacked the kidney.
Air sac White with bloody spattering inside or on the surface. The air sac is *extremely* sensitive to bacterial attack. Simply putting a needle in the air sac will cause overwhelming redness throughout the organ. Sometimes, overt hemorrhage of the air sac is all that you may see of a bacterial infection in the fish that has died.
this is only one example of how easy it is to learn to do things for ourselves. im sure there are other things that could be added to the above chart, but these are the things we learn through further researching.