Small sharks?

what examples of sharks look like the red tails yet stay small?

 

The only other one I can think of is a rainbow shark but they can still potentially get 6-8"

 

I wrote this in another thread and it got moved. mrsP mentioned that there are other sharks that look similar yet stay much smaller so I was just wondering! I have a 35 gallon

 

I wrote this in another thread and it got moved. mrsP mentioned that there are other sharks that look similar yet stay much smaller so I was just wondering! I have a 35 gallon

Following with interest to know if there is a smaller shark to keep.

 

Fish sizes are from All pond solutions pages.
Galaxy rasboras grow to 2-2.5cm and are beautiful schooling fish.
Rainbow sharks and albino sharks grow up to 12,5cm.
Siamese algae eater is similar body shape and grows to 15cm.
Spotted headstander 8cm.
Redtail banded rainbow fish up to 15cm.
Spotted blue eye 3,5cm.
And naturally my favorite, betta. There are huge amount of different bettas available, for example betta smaragdina. I think I need one of them myself.... but I need a new tank for it first.