big arse catfish.Three words for one suggestion,because if I remember Senegals are fairly sizeable,correct?I'm just saying that most catfish are friggin huge when they reach adulthood,like the pangasius catfish,more commonly known as the irredescent shark.It gets like a meter or somewhere in that area,or like maybe,I don't know,a Pacu.There IS a reason that Colosoma is in their scientific name.
Err, while large species are considered somewhat of a holy grail, why suggest them when he obviously won't be able to keep them? His tank is only 40 gallons, and even a 90 gallon upgrade wouldn't be that large. Most of the big fish mentioned on this thread so far would need a tank with at least a couple hundred gallons, in some cases like pacus and really big catfish, thousands would be more reasonable.
Senegal bichirs as well as most other bichirs will look like these guys.Violet gobies have a similar body shape, but much different care requirements. You'll want to make absolutely sure you know what species you have as even different species of bichir come in different sizes.
i agree, my sterbais and pygmys (in different tanks) are in groups of 6 and they are some of the best fun fish i have...
thinking about increasing the group sizes now.....(have plenty of space), i would love to have a group of 18 sterbais or pygmys!
I think you should consider the advice of an above poster- fish don't have to be huge or oddballs to have great personalities and heaps of fun.