Sorry to see your departed NTT, know how you feel, I lost a 10" NTT. Grew him out with six other thin bars, he was thinner than the others and I started hand feeding (with tongs) raw shrimp daily. After around one week of bulking him up I sat down to my morning coffee and witnessed him spaz out, hit the top glass of the tank, sink to the bottom, swim across to the other end and die.
Freaked me out, looking back I suspect the daily raw shrimp was the cause because of a chemical, the name escapes me, but it started with a T, and I've read since that too much raw shrimp is toxic to datnoids because of this certain chemical.
"Tripolyphosphate" Sodium Tripolyphosphate, STPP, found in cleaning products, paints, ceramics, and used as a food preservative.
Some time ago I read that tripolyphosphate, found in very small amounts in raw shrimp/market prawn could be toxic to datnoids, and the article recommended not feeding to tigers too frequently.
How accurate this write up was I can't say, but it would explain my 10" NTT's sudden death.
On the other hand over the years I raised many dats IT, ST NGT, on raw shrimp with no problems. Could be that NTT are more delicate and susceptible to tripolyphosphate.




