Every other dottyback on this coast is a loner that attacks its own kind on sight. This one is found in groups.
That is the whole point of it. Dottyback aggression is not a quirk, it is the business model: a small fish holds one hole and one patch of rock, and it holds them by being intolerable to everything of its own size. Two dottybacks in one crevice normally ends with one dottyback. Yet this species gathers over rubble in loose aggregations, sometimes dozens, feeding in the water above the bottom and dropping back into the rock together.
What lets it work is probably the food. A fish picking plankton out of the current is not defending a fixed resource the way one grazing a patch of substrate is, so the arithmetic of fighting stops paying, and tolerance is cheaper than war.
It is also one of the most striking fish of its size here: white with two clean black stripes running nose to tail and a forked tail with dark lobes. It runs from the 🌊 Red Sea down to Socotra (🇾🇪 Yemen) and stops there.
In the north it is scarce; it becomes much more common the further south you go.
The genus. Pseudochromis Rüppell 1835 - pseudo- (false). ETYFish
The species. Pseudochromis sankeyi Lubbock 1975 - Honours Richard D. Sankey. ETYFish
- two black stripes running the length of a white body
- forked tail with dark upper and lower lobes
- usually several together, which no other dottyback here does
- up to 8 cm
