Galaxias de bajo brillo superficial: analogas a los sat\'elites de
  Andr\'omeda en Pegasus I?
  Here we show the preliminary results of a study where there seems to be a
bias effect in the size distributions of the detected low-surface brightness
(LSB) galaxies in different environments. In this sense, more distant
groups/clusters would lack small effective radius objects, while large systems
would not found in the Local Group and nearby environments. While there may be
an actual shortage of large LSB galaxies in low-density environments like the
Local Group, the non-detection of small (and faint) systems at large distances
is clearly a selection effect. As an example, LSB galaxies with similar sizes
to those of the satellites of Andromeda in the Local Group, will be certainly
missed in a visual identification at the distance of Pegasus I.
