Old alien movie (late 80's early 90's)

[exia00]

I watched this movie when I was a kid cant really remember it.

A group of people was in a spaceship and there was an alien with them.  The alien had some kind of tentacles that sucks water from the people and left them dry like mummy.

The alien had something to do with a crystal, they shot the crystal to beat the alien down by the end of the movie.

Another scene was when a few survivors were inside a room when suddenly the oxygen level was dropping.  The alien somehow learned how to use the computer and changed the settings in the spaceship.
Also there was a time when another spaceship came in contact with them, but the survivors couldn't contact the other ship so it left them (I think the Alien sent a message to the other ship saying everything was OK, but I'm not so sure.)

There was also a short scene where the people could see on a screen life signals of the people and the alien, so they knew exactly where the alien was on the ship.

Anybody has any ideas? Thx

[akiratubo]

Some of that sounds like Star Crystal.

http://www.badmovies.org/movies/starcrystal/

[exia00]

yeah...that's the one..
i'm watching it right now on youtube

thx so much