Stellar Populations and the Star Formation Histories of LSB Galaxies:
  II. HII Regions
  The luminosities, colors and H\alpha\ emission for 429 HII regions in 54 LSB
galaxies are presented. While the number of HII regions per galaxy is lower in
LSB galaxies compared to star-forming irregulars and spirals, there is no
indication that the size or luminosity function of HII regions differs from
other galaxy types. The lower number of HII regions per galaxy is consistent
with their lower total star formation rates. The fraction of total
$L_{H\alpha}$ contributed by HII regions varies from 10 to 90% in LSB galaxies
(the rest of the H$\alpha$ emission being associated with a diffuse component)
with no correlation with galaxy stellar or gas mass. Bright HII regions have
bluer colors, similar to the trend in spirals; their number and luminosities
are consistent with the hypothesis that they are produced by the same HII
luminosity function as spirals. Comparison with stellar population models
indicates that the brightest HII regions in LSB galaxies range in cluster mass
from a few $10^3 M_{\sun}$ (e.g., $\rho$ Oph) to globular cluster sized systems
(e.g., 30 Dor) and that their ages are consistent with clusters from 2 to 15
Myrs old. The faintest HII regions are comparable to those in the LMC powered
by a single O or B star. Thus, star formation in LSB galaxies covers the full
range of stellar cluster mass.
