Loricariidae is a family name which is mostly plecos. The otocinclus catfish is placed into this family for the downward sucker mouth, but mainly due to the overlapping scales. The chinese algae eater and gold algae eater have a regular scale pattern unlike the oto cat and plecos, also if you notice the mouths of the CAE and GAE are more on the end of the snout and not on the bottom of the snout like plecos. These differences along with others puts the CAE and GAE in the family Gyrinocheilidae.