We assessed fitness of transgenic Tanichthys albonubes to food supply level using 7-days healthy larvae from crossing heterozygous transgenic T.albonubes expressing the red fluorescent protein to non-transgenic T.albonubes. The larvae were randomly divided into three groups: satiation group (high food supply level), semi-starvation group (medium food supply level) and starvation group (low food supply level) under (25.0 ± 2.0) ℃. The results showed that: (1) the mortality rate of 72-days of larvae in satiation group was not significantly different from those in semi-starvation group (P>0.05), but larvae in starvation group was significant difference from both satiation group and semi-starvation group (P<0.01). It indicates that food supply level affect the mortality rate of T.albonubes. (2) The red fluorescent protein was initially expression at 30-days larvae with visual inspection. The PCR method was used to make sure that there was no recessive expression in the three treatments at 72-days larval. At this point the number of transgenic and non-transgenic T.albonubes was close to the 1 ∶ 1 ratio, and consistent with classical Mendelian inheritance model, which indicates that transgenic and non-transgenic T.albonubes are equally effected by food supply level. (3) The body length at 28-, 42-, 57- and 72-days larvae was satiation group>semi-starvation group>starvation group at significant or very significant level (P<0.05 or P<0.01). The larvae body length of 72-days larvae has no significantly between transgenic and non-transgenic ones within the same food supply level group. In summary, the food supply level had similar influence on survival and growth of T.albonubes for both transgenic and non-transgenic. We speculate that transgenic T.albonubes have no competition advantage in the low food availability.