Copyright 1994 The Chronicle Publishing Co. The San Francisco Chronicle MAY 15, 1994, SUNDAY, SUNDAY EDITION SECTION: SUNDAY DATEBOOK; Pg. 40; LIVELY ARTS LENGTH: 768 words HEADLINE: Jellyfish All Washed Up BYLINE: MICHAEL SNYDER, Chronicle Staff Critic BODY: After only two albums, Jellyfish -- the blithe San Francisco pop-rock band -- has split apart. Apparently, that ol' demon ''creative differences'' has ended the musical collaboration of singer-percussionist Andy Sturmer and singer-keyboardist Roger Manni ng, the two childhood pals who gave Jellyfish its backbone. The two main 'Fish are already back in the swim with separate projects, co-managers Chris Coyle and Victor Ratto said. He hasn't received completed demos yet, but, according to Coyle, there will be two bands where there once was one. Despite a high-profile recording contract with Virgin Records that resulted in wonderfully baroque, harmony-laced releases such as the single ''The King Is Half-Undressed,'' Jellyfish never managed to attain the upper reaches of the American charts. Euro pean and Asian audiences were more receptive. ''Australia and Japan were breaking wide open for us,'' Coyle moaned, ''and the band was developing a devoted following in the states. We were doing turn-away business on the club and small-theater circuit.'' The group generally was lauded by the critics, although there was the occasional caveat about the musicians' obsession with late '60s and early '70s fashion and the hits of the Beatles, the Beach Boys and Queen. On the strength of the first Jellyfish alb um, Sturmer and Manning were asked to write some songs for Beatles drummer Ringo Starr, who recorded one of the compositions for his last solo album and had the duo provide backup vocals. Ironically, the Jellyfish song ''He's My Best Friend'' just showed up on the sound track of the frothy, gender-bending sex comedy ''Threesome.'' Sometimes, even best friends disagree. GRAPHIC: PHOTO,Jellyfish calls it quits after two albums