Hi,
Sorry but IMO that doesn't look at all like an L183 to me. I agree that the dorsal ray count must also be correct but without the white seam in tact I doubt very much that what you have there is an L183 at all. Also judging from the picture my breeding adults are considerably bigger maybe by half as much again. This is what an adult should like:
like.
http://ts1.mm.bing.net/th?&id=HN.607992096002214359&w=300&h=300&c=0&pid=1.9&rs=0&p=0
I've been keeping and breeding this species for some time now and mine are so much darker than the one shown with an inky black base colouration and tiny white spots even in the adults (although nowhere near as with the juveniles) and a pure white seam about 3mm wide on both the tail and the dorsal fin.
It has to be said that the fish in the picture is in poor condition and the fins in particular are in a very damaged state so maybe if it was in better shape it would look more like a true 'Starlight'. There is a tiny bit of white to the tail but this could just as easily be fin rot damage.
I also don't cocurr with the behavioral comments posted and think they are unjustified and misleading. If there are enough 'territoies' provided you shouldn't have any problems I certainly don't. Yes they are a bit messy but no more so than any other plecs of similar size and yes they do like wood but not as much as Panaque's and not enough to consider it as a problem. What they do like is algae and I never experience problems with black beard algae when I have L183's in the tank. They also like meaty foods and will completly devouir any dead fish often before you even have time to notice they are missing so in this respect they are great tank cleaners. The're peacefull and undemanding and very prolific IF you can get them breeding, just like any other ansistrus.
Regards Chris.