Rhamphichthys sp. ID?

[vind7]

Hey everyone,
I stumbled upon a Rhamphichthys sp. offered in a German online shop for aquarium fish.
I have always had a thing for knifefish and I am considering to order one however, some Rhamphichthys can get up to 100 cm long (R. rostratus) which is far too big for my tank, while others don't grow bigger than 20-40 cm (R. depranium).
Anyone here who houses Rhamphichthys? How long do they normally get in aquarium?
I included the picture which is used in the shop, sadly its incredibly small but maybe anyone here would be able to identify what kind of Rhamphichthys it is or maybe rule some out.

 

[Boomer1224]

don't know anything about this knife but it is really gorgeous

 

[vind7]

It definitely is! I am so tempted to order one but I can't house a 3 ft fish
Really hoping someone can get my hopes up and tell me it's not a rostratus

 

[blackbullhead]

Well, you're in luck...sort of. These are Rhamphichthys marmoratus, but I'd still expect them to get quite large. I can't say I've ever seen one that was 3 ft, but they certainly get up to 2 ft. or so. Very cool looking fish.

 

[vind7]

Well, you're in luck...sort of. These are Rhamphichthys marmoratus, but I'd still expect them to get quite large. I can't say I've ever seen one that was 3 ft, but they certainly get up to 2 ft. or so. Very cool looking fish.

How sure are you about that? I have looked them up and their max. size was said to be a little above 2 ft. but then again I doubt they will grow that large in captivity or do they?
Getting one of these is so tempting but I don't if I'd make the right choice ordering one.

 

[blackbullhead]

This seems to be the most commonly imported species, but I've never heard of anyone keeping one for an extended period of time. I've seen a number of dead specimens at a Peruvian fish market that were around 2 ft, so that's my only real source of info, here.

 

[Hendre]

Beautiful

 

[blackbullhead]

It seems these are a bit bigger than I remembered. I dug through my files and found this photo of a dead R. marmoratus measuring out to what looks like just over 27 inches. We have a handful of them at this size, so I'd say its reasonable to conclude that this is more or less the average adult size for this species.