Some questions about P.glutinosus

I´ve been trying to find as much info as possible about this specie but it´s surprisingly scarce.
I´ve noticed big adult animals have bright white dots on the sides, but dull and faded dots on the back (My biggest animal follows that "rule"), while juveniles have bright dots all over their bodies.
Is the faded dorsal spotting just a sign of age, or is it related with sexual maturity? Of course this two are related, but what i mean is if as soon as sexual maturity is achieved, the dorsal spots will fade.
I also have a question about nasolabial grooves. All my animals, even the smallest one seem to have very tiny but noticiable grooves. I thought this were exclusive of males, but i´m guessing both sexes have them, being the males who have larger grooves during mating season, is that right? Are the nasolabial grooves also related with sexual maturity?

My final question is about feeding habits. Being terrestrial salamanders that live in humid forests, i was expecting them to fancy slugs, but none of my animals care about them, they don´t even notice them. They take eartworms, wax worms and crickets without problems but they won´t touch anything else.

Oh, one final thing....i´ve read they are territorial(not agressive, but they do have territories). Mine don´t seem to. They share hiding places and they move from one shelter to another. Except one of them tht rarely comes out and is almost always underground. Is this normal or am i doing something wrong?

Hi Rodrigo, The easiest way to sex these salamanders is look at the chin, the male will have a round pad the female won't. The pad is always there but its more prominent in breeding season.The white spot issue is an age thing.

Thank you Ian.
I´ve had a hard time trying to see any differences between their chins, not only because they move a lot and are difficult to grab steady, but also because i have nothing to compare with. I´ll try my best to take pics and see if you can give me your opinion.
So, it means an animal with bright dorsal spots might be sexually mature(a young adult)?

Spot patterns are not a reliable indicator of sexual maturity. Though there may be trends with age, color pattern has not been documented in any significant way.

If you know age or can measure size that would be a better means. This is from Beamer and Lannoo's account for the species from Amphibiaweb:

L. Age/Size at Reproductive Maturity. The smallest mature female from Frederick County, Maryland, was 62 mm SVL; the smallest mature male was 60 mm. The smallest mature female from Bedford County, Pennsylvania, was 61 mm SVL and the smallest mature male was 54 mm SVL. Maturity in these populations is probably not reached until 4 yr old (but see also Semlitsch, 1980b). Females from these locations have a biennial breeding cycle (Highton, 1962b).
The smallest mature female from southern Illinois was 50 mm SVL and the smallest mature male was 47 mm SVL. Maturity in these populations may be reached at 3 yr old (Highton, 1962b). The smallest mature female from Giles County, Virginia, was 57 mm SVL and the smallest mature male was 45 mm SVL. Maturity in these populations is probably reached at the age of 3 or 4 (Pope and Pope, 1949; Highton, 1962b).
The smallest male with a well-developed mental gland in Ohio was 48 mm SVL (Pfingsten, 1989d).


Hope that helps some.
-Tim

One other suggestion, it is much easier to view the chin if you place the salamander in a clear deli container or glass bowl. This is how I sex most of the plethodontids I care for.
-Tim

Thank you very much Taherman. I took them out of the terrarium this early afternoon(not easy....) and did exactly that...i put them on a transparent container and took a look. I have a juvenile, still way too small, one that could be a female but i think it´s still just not mature and what i believe is a mature male. I´ll try to messure the male and the possibly young female.
The coloration thing was just a guess i had made based on my animals size and coloration and a few pics, it was mostly curiosity. Thanx for clearing that up.

About the one i think is a male...it´s got just a clearer patch on the chin, is not prominent and it´s quite subtle. Is that what the mental gland is supossed to look like out of breeding season?
Thank you for your time.

Yes, it will just look like a lightly pigmented circular area, during the breeding season it will appear slightly raised compared to surrounding skin and more prominent.

Good luck with your pair!
-Tim

http://www.freewebs.com/slimysalamanders/northernslimys.htm

Here is pictures telling the difference.

Thank you Cameron, my problem is that they are either too young or out of breeding season, so i needed to see what a mental gland out of season looks like, but it was very helpfull nevertheless. In your photos i couldn´t see even the slightless sign of nasolabial grooves on the female, i thought both had them, males having the bigger more obvious ones.

Females do not have them.

To clarify, all plethodontids of both sexes have nasolabial grooves, however they are more apparent in some some species, and often in males. They can be very difficult to see with the naked eye sometimes. Females do lack mental glands.

-Tim

Most of the salamanders I've encountered (actually a lot of herps in general) tend to have more vibrant coloration when they are younger, I'm not sure it has anything to do w/sexual maturity though.

As for their diet, I wouldn't worry too much, although you tend to see slugs in many of the same places you'll find salamanders, you'll also find a great deal of earthworms and beetles too (among other insects), so it may just be that they prefer one over the other.

I'm not sure about the territorial thing, but I know I've found slimy's under rocks around the the base of the same tree (about a foot apart), they weren't very large one's so maybe their range increases with age, or they are more territorial when they are close to mating season.

Hope this helped, and if anyone can correct any of my points it'd be greatly appreciated, I'm by no means an expert.