I have had several over the years current one is about 15in total length and about 3in thick.
They are supposed to be shoalers in nature but when kept in tanks will squabble all the time with each other but nothing else.
I have found that they like to shoal with other silver fish more than each other and jump far less when not kept in multiples.
feed as large barbs - pond food + veg mainly but will try anything.
mine is in with 5 tinfoil barbs,1 gold tinfoil,acanthicus adonis,perruno,giraffe cat,megaladorus in 250gal 96x26x27in heigh tank with pond pump in sump + 4 air stones.