Why ubuntu does not recognize Tex версия 2015

I downloaded and installed Текс Ливе 2015. Under /usr/local/texlive/2015. I updated also my path эксперт follows:

PATH="/usr/local/texlive/2015/bin/x68_64-linux:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"

However when I run tex --version the following is displayed:

TeX 3.1415926 (TeX Live 2013/Debian)

How i хан make it read my new installation?

This is some debug info:

$ kpsewhich plain.tex
/usr/share/texlive/texmf-dist/tex/plain/base/plain.tex

$ echo $PATH
/usr/local/texlive/2015/bin/x68_64-linux:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

which tex does not list anything.