Terror-Cotta have officially confirmed the release date for the anime adaptation of Gyo is the 03rd of September and along with the release date they have sent a UK trailer - one which reveals far less than the original Japanese one and works far better. Here are the details and the trailer:

GYO: TOKYO FISH ATTACK

Giant, killer fish attack Tokyo!

Release Date: 03rd September 2012

Synopsis

The story centres around Kaori who is visiting Okinawa and its beautiful beaches with friends when she find herself caught in the middle of a land invasion by bizarre and aggressive fish which scuttle on land with sharp metal legs. Things are about to get much worse for Kaori as she finds that the deadly fish are spreading from the island.

Terror-cotta state that "Morbid manga master Junji Ito's putrid and surreal story of mutant zombie fish that sprout legs and attack Japan is the most insane anime to come out of Japan since Urotsukidōji:  Legend of the Overfiend; Directed by Takayuki Hirao and released on DVD following its success at the Terror Cotta Horror movie marathon part of Terracotta Festival in association with Film Four Frightfest."

Technical Specifications
Special features:
Interview with Manga master Junji Ito
 
Horror, 2012
Certificate 15
Country: Japan
Language: Japanese with English subtitles.
Running time: 71 min