Yes I meant hardier - I´m not a native english speaker so it goes wrong now and then - We can say that I write English with a slight Swedish accident"hardier" not "harder" correct
If I have had more than 1 - it has work for 1 - 2 years - if they have been only one more than 3 years - this last have lived for 4 years. They was two at first but they are rather Intraspecies aggressive and I think that the one that survive was bulling the other. I introduce 2 tanaka to this aquarium but - at that time - there was not enough of space in a 80 G tank for tfour Wetmorella. In my old tank - 120 G it also also always ended up with 1 after a year or two. It is around 12 years since the first Wetmorella hit my apartment.
You can´t compare clown gobies activity with Wetmorella - you can see the clown gobies as snails and the wetmorella as a gazelle. In 20 sec i can see my yellow banded in the right corner - left corner and back in right again. My clown gobies have during the same time moved from one coral to the next (nearest) coral (maybe 2 cm).
Even though it is a small fish, they have large territories. They are beautiful and small fishes - but sorry to say - they are not any fish that will thrive in a nano.
However - it's your choice - I would not put any Wetmorella in an aquarium shorter than 1 m.
Sincerely Lasse