When I started the blog several years ago, one of my goals was to make it as comprehensive as possible. By comprehensive, I meant I would try to include information about all cichlids, not just what I keep or have a lot of experience with. To meet that goal, I knew I would have to get information from other sources. Hence, the interviews. By interviewing hobbyists, breeders, business people, and other experts, I can share with you information from a variety of people who have the experience I lack. This leads me to angelfish. Though they are quite popular in the hobby, I’ve never kept them. So I contacted an expert.
Steve Rybicki has been breeding and selling fish for several decades. In 1987, he and a friend started a tropical fish business called Angels Plus. In 1996, Angels Plus became the first online retailer dedicated to angelfish and for 32 years it is has been a full-time hatchery that specializes in show-quality fish, housing over 400 tanks.
Thankfully, Steve was quickly onboard for the interview. Let’s get going.
Frequent water changes are widely hailed as a key variable in the well being of aquarium fish, especially cichlids. However, for at least one species of angelfish, fewer water changes may actually be beneficial, especially if your angelfish population is somewhat dense.
According to an article published in the January 2018 issue of Applied Animal Behavior Science, frequent or large water changes in aquariums housing Pterophyllum scalare may actually increase con-specific aggression in this species. The authors posit that water changes modify cortisol and other chemical levels that these angelfish use to establish social status. Frequent and/or large water changes dilute these chemicals, which effectively disturbs the baselines that set the statuses thus requiring that the angelfish re-establish them.
Less water renewal reduces effects on social aggression of the cichlid Pterophyllum scalare. Gauy, Ana Carolina dos Santos et al. Applied Animal Behaviour Science (2018). Volume 198, pp. 121 – 126. https://doi.org/10.1016/j.applanim.2017.10.003.