How do I tell if I have a male or female bristlenose (Ancistrus spp.)?
Some cases are obvious: Males have big head tentacles and females don’t, but it’s not always so clear-cut. First of all, some females do get head tentacles – although not to the same extent as a male from the same species – which can make it hard to determine if the fish is a young male or older female. It can be useful to be able to determine if a young fish is male or female, before the head tentacles have grown, so here are a few pointers. If you have multiple reasons that all point in the same direction, you have more confidence that it is either male or female. (1) Head tentacles up into the face. Males will have head tentacles above the edge of the snout. (2) Forked head tentacles. Males of many species will have forked head tentacles, females don’t. (3) Ridge in the face. On males, the snout has a ridge going from the tip of the snout up towards the middle between the eyes. (4) Body shape. Another part of the puzzle is the shape of the body – females tend to be wider around the
