ID please. Imported as Otocinclus arnoldi

[bekateen]

Imported as "Otocinclus arnoldi." I got really excited because I was expecting

Otocinclus flexilis

, which is the valid name for this fish.

The CLOG says O. flexilis is a mimic of

Corydoras paleatus

. Although I'm not eager to buy C. paleatus, I love the idea of having a cory mimic in a tank with corys, and I was looking forward to putting the O. flexilis in with my

Corydoras diphyes

, which superficially resembles C. paleatus. Plus, O. flexilis is a cool water species like C. diphyes, and according to the CLOG, O. flexilis is not so dependent on algae to survive (I'm not good at keeping common otos because my tanks don't have enough algae for them).

But the fish that arrived don't look right. Two large dark spots at tail base and a vertically striped tail very distinctive, doesn't match common oto spp. Maybe

Otocinclus huaorani

?

Other ideas??

Thanks, Eric

[bekateen]

Actually, I have a different question now:

After looking at the Catalog of Fishes, I see they consider O. arnoldi a valid species, and its original description says it's similar to

Otocinclus affinis

and

Otocinclus vittatus

.

The fish that my LFS received does look similar to these other two spp., so perhaps the fish we received are O. arnoldi and we need to fix our CLOG to list O. arnoldi as a recognized species?

Cheers, Eric

[Jools]

O. arnoldi has be re-validated, however, it is a species that shouldn't be ID'ed on a photo. It also appears to be a peppered species that sometimes has a lateral stripe and occurs out with common collection sites. I think this is described in the undernoted paper but I can't find a copy.

Lehmann A.P., F. Mayer and R.E. Reis, 2010. Re-validation of Otocinclus arnoldi Regan and reappraisal of Otocinclus phylogeny (Siluriformes: Loricariidae). Neotrop. Ichthyol. 8(1):57-68. (Ref. 86395).

Jools

[bekateen]

Thanks Jools. Are you looking for this Lehmann paper:
Pablo Lehmann A., Fernanda Mayer, & Roberto E. Reis. 2010. Re-validation of Otocinclus arnoldi Regan and reappraisal of Otocinclus phylogeny (Siluriformes: Loricariidae). Neotropical Ichthyology, 8(1), 57-68.

http://dx.doi.org/10.1590/S1679-62252010000100008

Cheers, Eric

[bekateen]

None of the fish we received have the yellow/orange/tan body base color that flexilis has, and none of the fish we received has any body blotches. But they do at least superficially resemble the O. arnoldi shown in Figure 3.c above.

[Acanthicus]

Morning everybody,

the fishes from the original post look like O. macrospilus, the most common Otocinclus sp. in the trade.
In O. huaroni the lateral stripe doesn't get slimmer towards the caudal peduncle and the caudal spot is smaller than in O. macrospilus: http://www.l-welse.com/reviewpost/showp ... 37/cat/all

If you keep C. diphyes already, try to get O. mimulus, which would be the "correct" species to form the mimikry-pair.

[bekateen]

Thanks Daniel.

Interesting you picked

Otocinclus macrospilus

as the fish in the OP, because we also received a bag of "O. cf. macrospilus." And yes I thought they were similar, but not exactly the same. We also got

Otocinclus affinis

and Otocinclus negros (which is

Otothyropsis piribebuy

), and

Otocinclus cocama

.

As for a mimic for my diphyes, I'll keep my eyes open for

Otocinclus mimulus

. Although to be honest, I avoid most Otos because I can't keep them alive well - their food requirements are described as too similar to common Otos (which I've kept 3 times before, and all died within a couple of months). The C. paleatus mimic O. flexilis appeals to me more both on appearance and on the description of its atypical feeding habits, which are more in line with other fish I keep. So maybe I'm still better off with O. flexilis and I'll pick up some C. paleatus for company. No matter for now, as neither oto is available at the moment.

Thanks, Eric