We study the baryon content of low mass galaxies selected from the Sloan Digital Sky Survey ( SDSS DR8 ) , focusing on galaxies in isolated environments where the complicating physics of galaxy-galaxy interactions are minimized .
We measure neutral hydrogen ( HI ) gas masses and line-widths for 148 isolated galaxies with stellar mass between 10 ^ { 7 } and 10 ^ { 9.5 } M _ { \odot } .
We compare isolated low mass galaxies to more massive galaxies and galaxies in denser environments by remeasuring HI emission lines from the Arecibo Legacy Fast ALFA ( ALFALFA ) survey 40 % data release .
All isolated low mass galaxies either have large atomic gas fractions or large atomic gas fractions can not be ruled out via their upper limits .
We measure a median atomic gas fraction of f _ { gas } = 0.81 \pm 0.13 for our isolated low mass sample with no systems below 0.30 .
At all stellar masses , the correlations between galaxy radius , baryonic mass and velocity width are not significantly affected by environment .
Finally , we estimate a median baryon to total dynamical mass fraction of f _ { baryon,disk } = 0.15 \pm 0.17 .
We also estimate two different median baryon to halo mass fractions using the results of semi-analytic models ( f _ { baryon,halo } = 0.04 \pm 0.06 ) and abundance matching ( f _ { baryon,halo } = 0.04 \pm 0.02 ) .
Baryon fractions estimated directly using HI observations appear independent of environment and maximum circular velocity , while baryon fractions estimated using abundance matching show a significant depletion of baryons at low maximum circular velocities .