Reptile & Amphibian Forums

I have two Oregon newts, the female about 4-5 years old, and the male about 5-6. They mate all the time, but I've never seen any eggs. I know a *little* bit about breeding conditions and habits, but I just wanted to check a few things with you guys:

1. I have heard (online somewhere, I don't remember where) that Oregons can mate all they want, but will not actually reproduce until they're sexually mature. Is that true, and if so, are mine old enough?

2. How many eggs will a typical Oregon female produce? I have heard it's anywhere from 200-1000, and I have heard that this species onl produces 12-20 at a time. Which is it?

3. Romeo, the male, is a good deal larger than Lita, a tad darker, a tad rougher in the skin, with nearly black eyes (where hers are very pale and yellowy). I've often wondered if he's just a big, dark Oregon, or if one or the other is actually a California Newt. If I actually have one of each, can they interbreed successfully?

Just thought I'd share this: these two mate every friday night from 8pm-2am. Seriously, you can set your clocks by this pair! I have no idea why they don't mate at other times (unless they do while I'm at work and I just don't know about it), or why they're so regular. My husband's friend Daniel comes over every friday night, and the two times he hasn't shown up, the newts haven't mated - the going theory is that Daniel puts them in the mood! ;D

Hello,

If they are in fact a male and female pair entering amplexus often, then there could be a few things going on here.

1) They may not be sexually mature, but are going through the motions. It is true that in the wild most Taricha granulosa, and Taricha torosa for that matter, juveniles (non-sexually mature individuals) will return to their ponds with the sexually mature adults each breeding season, but will not actually reproduce. The migration of Taricha species is interesting because it is thought that they leave behind chemical scents each season so they can find their way back to the same pond (usually they one they emerged from). It is possible that they are not sexually mature yet, but are going through the motions. Taricha speices can reach sexual maturity anywhere from 3-8 years of age. In the wild, it is usually around 5-6 years, but anywhere from 2-5 years with captive bred species.

2) They may be reproducing, but consuming the eggs before you find them. This is very common in some other species, especially Pleurodeles waltl (Spanish Ribbed Newt).

3) The female may not be responsive to the male. Males amplex females at will, regardless if they are gravid or not. They have even been known to amplex other species (I've seen a photo of this before).

4) You may not have a male-female pair. Males turn light colored, with very smooth skin during the breeding season. Females stay rather granulous, which is a very noticable contrast compared to the males.

There are a few other possibilities, but I think these are the most likely. Because you mention that "Romeo" has rough skin, this leads me to wonder if Romeo is a female, or if maybe they're not really amplexing.

Yes, Rough-Skinned Newts (Oregon Newts) can hybridize with California Newts. These two species are difficult to tell apart, but Rough Skinned's are more common than California Newts. Color alone does not differentiate them. The only sure way to tell is bye comparing the vomerine teeth shape, or the coloration below the eyes. I have written an article on the California Newt that can also pertain to the Rough Skinned Newt as far as breeding and sexual dimorphism is concerned. Here is a link to that article, and a few more references:

http://www.livingunderworld.org/caudata/database/salamandridae/taricha/torosa/

http://www.livingunderworld.org/gallery/photos/caudata/salamandridae/taricha/granulosa/

http://www.livingunderworld.org/gallery/photos/caudata/salamandridae/taricha/torosa/

http://elib.cs.berkeley.edu/cgi-bin/amphib_query?table=amphib&special=one_record&where-genus=Taricha&where-species=granulosa

I hope this helps, and please feel free to email if you have any questions.

Jessica

Thank you, Jessica, that helped me a lot, and I learned more about my favorite little guys

On mating behavior/characteristics:
Romeo does indeed get more smooth during the times he amplexes Lita, his tail does seem to flatten out quite a bit, and his cloacal region becomes REALLY swollen, as well. I haven't noticed that his skin turns lighter, but I'll be sure to pay attention this weekend, if they keep thier schedule. Lita goes through no changes at all that I've noticed.

On species identification:
Romeo's eyes do protrude more than Lita's, and his lower-eyelid area is indeed a lighter brown than the rest of his face - Lita's whole face is the same color. I've never witnessed either of them in the defensive posture you talked about, so I'm not sure how they act when they do that. The teeth thing confuses me - I knew they had teeth, but I've never seen them (I had thought they were too small to see). This Y-shape vs. V-shape thing: does this refer to the shape of an individual tooth, or the pattern the row of teeth makes in thier mouth (like humans having a U-shaped pattern)?

Again, thanks! I love learning more about my animules

The most obvious possibility, that I forgot to mention before, is the female might not be gravid. Is her abdomen unusally swollen? If not, then she's probably not carring any eggs.

The skin lightening may be very subtle in your particular individual; there are always exceptions to every rule. A few sure ways to tell if it's a male is by the smooth skin, swollen cloaca, and the amplexus position (the male grasps the female from above). The females typically don't show any significant change in physical appearance, except maybe a slightly laterally compressed tail.

It is possible that you do have one Taricha granulosa male and a Taricha torosa female. I don't think this would hinder breeding behavior much because they readily hybridize in the wild. However, I don't know this for sure because I have never actually observed the two species mating with eachother.

Another vague possibility is that because T. torosa are usually completely terrestrial during the summer, and T. granulosa are sometimes found in the water during the summer, the mating season may just be off for the two species. This may be a little far fetched if the female is T. torosa, and she is in the water willingly. But, as long as the temperatures remain cool enough, T. torosa, and T. granulosa, will remain in the water.

I should have said the pattern of the vomerince teeth, not the individual tooth shape. Although this is the most accurate distinctive characteristic, the lower lid color is almost always accurate.

I think the only way to really know for sure what's going on is to observe their behavior when they begin coming out of amplexus. This may be difficult though, since you said they start at night, and amplexus could last for hours. But if you could, you would be able to see if the male actually deposits a spermatophore, and if the female picks it up.

About the eggs, they do produce 100 eggs per season, but in small numbers over a few months time, not all at once.

I have also experienced "clockwork amplexus" with T. torosa and T. granulosa, and heard of others with the same story. Just another interesting aspect of these creatures of habit.

Jessica