To me this looks like a L129 based on what I read in the Cat-eLog and the forums, but the differences are rather subtle between these and a few others in my understanding. Note that this fish is about 2" TL.
First, a few pictures:
I know it's not a perfect angle on the underside, but am I right that it looks pretty gaunt? My common Ancistrus always had its stomach fully convex and when the Ancistrus was on the glass, it's stomach would be touching the glass as well. I don't have experience with Hypancistrus sp. so I'm not sure how much is this fish being young and poorly-fed versus a difference in how the species looks.
I'd also love to know if this is a male or female, though maybe it's too young and hungry to say for sure. I bought it thinking it was probably female and still think it is just because it seems to have the broad body that I associate with females. I could not spot any odontodes on the pectoral fin which I think males develop.
Lastly, I wonder if it was right to buy just one. The common Ancistrus that I had in this tank previously was always gregarious and got along with everyone. I saw this L129 as basically a prettier version of the common Ancistrus with a more varied diet. Reading around the forums here, I've read a few scattered comments suggesting perhaps L129 do not get as large as the common Ancistrus and also that their behavior is more confident in the presence of conspecifics.
With that said, I'm not sure if my current stocking levels would make adding 1 or 2 more appropriate. Here's the details on the tank:
Standard 29 US gallon tank, 30" long by 18" tall. Much of the surface area of the bottom is covered by driftwood branches intentionally arranged to create hiding places and grazing areas. There are also aquatic plants, most notably an Echinodorus sp. (an Amazon sword) that will ultimately take up much of one side of the tank's planting area. Filter is an Aquaclear 70, no carbon and a lot of extra biomedia. There is also a Hydor Koralia Nano circulation pump I added to help deal with cyanobacteria. I have a sponge filter as well but I treat it more as insurance in case the power filter breaks and as something for fish to graze on. There are two tubular pleco caves from plecocaves.com, each with about 1.5" opening and 6" long. Substrate is Estes black sand.
Temperature is 76F, pH settles in at about 6.5, 5-6 dGH, 2-3 dKH. Nitrates are rarely zero, but never above 20ppm. I test for nitrates regularly with a Seachem liquid kit because I dose plant fertilizers when the nitrates get very low. I do weekly 50% water changes. The water parameters described above are how they are when doing water changes with my tap water, so I don't use RO or any of that. The tank has been up and running for almost 3 years now though the cast of characters and the decor has changed somewhat.
- 2 Laetacara curviceps (probably L. dorsigera, actually)
- 12 rummynose tetras (Hemigrammus bleheri)
- 12 Corydoras habrosus
- 8 otos (presumably a mixture of O. vittatus and O. affinis)
- 2 female Centromochlus perugiae
- A few nerite snails
For now, I've been focused on trying to make sure the L129 eats, but I haven't been able to say for 100% certain whether it has. It seemed uninterested in the zucchini I put it in for the otos. Has shown interest in some other foods (New Life Spectrum flake/pellets, spirulina flakes, bloodworms), at least in the sense that it starts moving around when the food goes in. I've put some of this stuff in after dark so I can't know for sure who ate it. I also put a little piece of krill in the pleco cave while the L129 was in it, so it may have eaten it but it was too dark for me to see. It moves along the glass and driftwood, but it's hard to say whether it's getting food from those places.