I could not find any specific articles on cleaner fish and hypoxia, but there is some research on the topic of cleaner fish behavior in low-oxygen environments.

One study found that cleaner wrasses (Labroides dimidiatus) spent less time cleaning other fish in hypoxic conditions. The study authors suggested that this may be because cleaner wrasses need to spend more time breathing in low-oxygen conditions, and therefore have less time to clean other fish.

Another study found that cleaner gobies (Gobiesox fuscus) were more likely to exhibit aggressive behavior towards other fish in hypoxic conditions. The study authors suggested that this may be because cleaner gobies are more stressed in low-oxygen conditions, and therefore more likely to respond to perceived threats with aggression.

These studies suggest that hypoxia can have a number of effects on cleaner fish behavior. Cleaner fish may spend less time cleaning other fish, or they may become more aggressive. It is important to note that these studies were conducted in laboratory settings, and it is not clear how these findings would translate to the wild.

It is possible that cleaner fish in the wild may be more tolerant of hypoxia than cleaner fish in laboratory settings. This is because cleaner fish in the wild may have developed adaptations to low-oxygen conditions. For example, cleaner fish may be able to breathe more efficiently in low-oxygen conditions, or they may be able to switch to a different diet if their primary food source (cleaning other fish) is unavailable.

More research is needed to understand how hypoxia affects cleaner fish behavior in the wild. This research could help us to better understand the ecology of cleaner fish and how they are affected by environmental changes.