those are healthy nice altums, and i would assume those are atabapo altums. all altums have long fins. either orinoco or atabapo or venturi or rio negro altums it doesnt matter. the OP altums are fairly young still. it should have nice long fins unless shipping and stressed and diseased happened causing their fins to rot away giving that short fin look. and bigger altums are more sensitive to ship especially straight from south america. i sold some altums to a friend. one year later. my altums look way nicer than his. his have short fins while mine are longer than his. all from same batch as mine as well. cant really tell which river altums come from based on their long or short fins. all altums have long fins. i believe the soft water maintains that long fin. thats why every wild caught altums from the wild have ridiculous long nice fins. but if youre water isnt good their fins dont get so long. i have noticed most of the nice altums in captivity i see from videos with long fins are from europe or asia. i believe their water is a lot softer with lower ph and they use a lot of rain water in their tank. which are perfect for south american fish. but true atabapo's or not. most altums look very similar. it all depends on the water and care in my opinion.
look up jj ong altums. i believe his are true orinoco if i recall correctly over at finarama. and he has some of the biggest and best looking altums i have ever seen on youtube and i have pretty much seen all altums vids on youtube. only person that can compete with his altums are this youtube guy that has some venturi altums. they are always massive. but they look different than jj ong's altum.
jj ong altums, check out his vid when he first got the altums. very long fins.
venturi altums these are massive aswell. but u can tell these look diff than jj ong orinoco.
