It's quite amazing that a Pleco can end up looking like Hypancistrus zebra. It's no less amazing that there's another form of Hypancistrus in Rio Xingu, Brazil trying to benefit from looking the same way! L173 was (and still is by many) actually thought to be a form of H.zebra with wavy lines, but it's not. It's indeed a different species, and it's extremely rare. It's not allowed for export from Brazil, so captive breeding programs are necessary if we are to enjoy it's existance in the hobby. It's a hardy and easy to care for species when settled.
Name: Hypancistrus sp.L173
Trade names: False Zebra Pleco, L173
Origin: Rio Xingu, Brazil
Maximum size: 12 cm / 5''
Compared to the similar H.zebra, L173 is a bigger fish. It has a higher back, longer caudal fin and usually less straight black lines – at least when adult. But most importantly, L173 has brown eyes, H.zebra has silver or blue eyes. However, the variability of L173 is interesting in it's own right. It seems like the zebra pattern is not very well defined in their genes, so offspring may not always look as much like H.zebra as their parents do. Personally I'm tempted to believe that L173 is the same species as L399/400, which again may be just a form of L66. Clearly the rapids of Xingu make room for local adaptations and variations in appearance, although the variation is unusually remarkable within the wormlined Hypancistrus. There seems to be some possible mimicry of L174 and H.zebra going on. The true L173 is a very sought after fish, and the majority of the public don't understand the variability hiding beneath their skin. This leads to unfortunate and heated debates and accusations.
As with other Hypancistrus from Rio Xingu, L173 needs an aquarium set up consisting of lots of hiding places in the form of rocks, wood and of course specially made caves that suit their measurements. In these the males will eventually guard their offspring. They prefer water that is fairly warm (27-30 C), soft and slightly acidic. Most of all it should be well oxygenated and clean, so a good filtration system and frequent water changes are essential. Among themselves they are fairly peaceful, although males may quarrel for caves and females can sometimes be badly injured or even killed during the breeding-trapping in the male's cave. Males develop longer odontodes on their pectoral fins and on their cheeks, and have broader heads. Hypancistrus are mostly carnivorous, so a selection of crustaceans, insect larvae and fish meat should be offered along with high quality dried foods that also contain some vegetable matter.