Strawberrys are definitely aggressive. Not as bad as a similar sized bicolor or diadema, but not by much. Our strawberry definitely showed our slightly smaller diadema who's boss.
I don't know enough about orchids, but guessing they are similar to a 'peaceful' damsel?
Let me be clear one more time - in terms of ranking aggressiveness, strawberry dottybacks (
Pictichromis porphyrea) are generally considered by most "experts" to be less aggressive than many species in various genera (
Labricinus,
Ogilbyina,
Pholidochromis, even some
Pseudochromis like
P. aldabraensis and
P. fuscus), including their own (see
P. diadema and
P. paccagnellae). There are also many variables that play a role in territorial behavior we call "aggressiveness", such as sex, size, niche competition, food availability, congeners/ social grouping, size of the aquarium, order of introduction to aquarium, etc.
Any dottyback (even some of the most "peaceful species) can be aggressive towards passive fish like firefish given certain parameters. A larger strawberry behaving aggressively towards a smaller diadema is hardly surprising, although not knowing some of the other parameters involved (see order of introduction and size of the aquarium) means one is predisposing that strawberry dottybacks are more aggressive than diadema dottybacks, which is based on one anecdotal observation. I had an elongate dottyback (considered by most to be quite "peaceful for a dottyback) act aggressively towards a small damsel in a 10 gallon nano because it was "established" first in the tank, and when moved to a 40B after other fish were established, it did nothing but hide for several weeks - what were the differences in parameters that led to a change in that fish's behavior?
As I stated previously, strawberry dottybacks are typically considered less aggressive than many other dottyback species, but this does
not mean they cannot be aggressive under certain circumstances! The OP made a typical "rookie" mistake (order of introduction primarily), which troubles me as it is so easily researched and prevented. Explaining that all strawberry dottybacks are aggressive because you had one that was does nothing to improve the OP's understanding of what went wrong, just as explaining that my current one is non-aggressive is unhelpful - the reason for the behavior, and the probability of predicting what will happen under certain circumstances is more important to the OP's issue.
