You can tell if your pleco is male or female by noting differences in the following traits:
- Size – Female plecos are generally larger than male plecos.
- Body shape – Female plecos have a more rounded abdomen, especially when breeding. Meanwhile, male plecos look skinnier and more elongated.
- Bristles – Male plecos usually have longer and more pronounced bristles at the front of their pectoral fins and the edges of their heads and mouths. Female plecos might have short bristles on the edges of their mouths or no bristles at all.
- Behavior – Male plecos are usually more aggressive and territorial, while the females are more docile and friendly.