Eric, here is the best study I could find to prove my point...
http://scholar.lib.vt.edu/theses/available/etd-05212003-112151/unrestricted/FinalThesisETD.pdf Check out pages 6-11 but the whole study is quite interesting. Anyone who is an HSB lover and or striped bass lover, there is a lot of interesting info in the study!
Just like with large striped bass, say those fish in excess of 15 pounds or so, large HSB say those fish in excess of 8 pounds require cool well oxygenated water. It appears HSB are a hair bit more tolerant of warmer lower DO waters than are full blooded stripers, but not by all that much...
All you ever want to know or need to know about Striped Bass and Hybrids can be found in the American Fisheries Society publication "Culture and Propogation of Striped Bass and its Hybrids".
Pricy manual but necessary for serious discussions.
Points being raised about HSB mortality, DO and temperature tolerance has been discussed at great length previously by Condello, Overton, West and others.
I would recommend archival search for both academic and anecdotal informatioin regarding HSB.
