Color (g,r and i band composite) images from the SDSS alongside 21-cm Hi line spectra of galaxies clearly detected at Arecibo. The size of each image is 2′× 2′ with the NIBLES source number indicated in the upper left corner, absolute z-band magnitude, M_z, in the top center and log(M_HI) in M_⊙ in the top right corner of each image. The vertical axis in the spectra is flux density in mJy, the horizontal axis is heliocentric radial velocity (cz) in km s^-1. The SDSS recession velocity is denoted by a vertical dashed magenta line, the mean Hi velocity by the blue triangle, and the W₅₀ line width by the horizontal blue arrow bar. Confused galaxies are denoted by their confusion code from Sect. 4 in the upper right portion of the spectrum. Velocity resolution is 18.7 km s^-1.