“Anemic” spirals within the SDSS database by looking for galaxies with a high [[$C_{in}$]{}]{}value (indicating a face–on spiral galaxy; see Shimasaku et al. 2001) but with no detected emission lines in their SDSS spectra. In total, they found 73 such galaxies, which comprises of only 0.28$\pm$0.03% of all spiral galaxies with the same [[$C_{in}$]{}]{}parameter values, but with detected emission lines. I show some examples of these “Passive Spirals” in Figure \[pass\].

The most interesting discovery of Goto et al. is the distribution of local densities for these “Passive Spirals”, which peaks at $\simeq
1 h^2_{75}{\rm Mpc^{-2}}$. Therefore, these galaxies appear to be preferential located close to the critical density discussed above for the SFR–Density and [[$T$–R]{}]{}relations, [*i.e.*]{}, in the in–fall regions of C4 clusters. This is consistent with the observed decrease in the late spiral galaxies (Sc’s) witnessed in Figure \[critical\].

In summary, the quality and quantity of the SDSS data allows us to study the environmental dependences of galaxy properties in greater detail than before. There does appear to be at least one critical density (at $\simeq 1 h^2_{75}{\rm Mpc^{-2}}$) affecting the properties of galaxies and this could be due to the slow strangulation of star–formation in these spiral 