L600 sex?

[legion94]

I bought 2 l600 as pair from Manaus, have them for 4 days. One of fhem is 31cm, the second 27cm. Imo smaller is male. Need to sex bigger. Firstly pics od bigger:

 

[Tristan & Cichlid]

Female Pleco’s look bigger and have a rounder body shape. Females are also less agressive then males. The male looks more sleek and streamlined compared to the female. Hope this helps!

 

[Fallen_Leaves16]

Female Pleco’s look bigger and have a rounder body shape. Females are also less agressive then males. The male looks more sleek and streamlined compared to the female. Hope this helps!

Body shape isn't very reliable a factor, as older, well-fed males may look just as round, if not rounder, than females, especially compared to females that aren't conditioned well or have recently laid eggs. Additionally, adult males are more often larger than a female. Aggression and territoriality varies widely based on species and environment, as well as many other factors; and cannot be considered a reliable means of sexing, in my opinion. I've seen many Hypancistrus and Ancistrus females beat up younger males.


I don't have nearly enough experience with big Pseudacanthus to form a reasonable judgement on sex; though I would lean towards male, simply due to the larger head and the fact that imports of large, sexually-mature plecos tend to be heavily skewed towards male due to ease of collection. The lack of heavier odontode growth may likely be a result of the stress of collection and transit in captivity. Could very easily be wrong, though.
Then again, this thread is about a month old and I don't see much point in reviving it, seeing as the OP may not be too likely to make another appearance.