Puffer Fish or Blow Fish

Beware. On a recent kayak-fishing trip to the Sea of Cortez, Baja,
Mexico, near Bahia de Los Angeles, my wife's Russian mother died of
puffer fish poison. We all ate the meat of the fish (not knowing that
such poisonous fish existed there). My mother in law also made a soup
of the heads and livers, which apparently is a tradition in some parts
of Russia). We all drank some of the soup as well, but apparently (we
don't know for sure) only she actually ate a liver. She died a violent
death within 30 minutes of eating it. The rest of us were fine. We
were on a remote beach miles from anywhere so there was no chance to
get help in time. In any case, there is no known antidote.

The fish was brownish in color, similar to the local small sea-bass
that we usually caught there. One tell-tale sign of the fish we ate
was the odd, fused teeth, which appear almost human. Also, the fish
may puff up while being caught.