Echinotriton vs. Tylototriton

Hi Wouter. Well, I'm unaware of the reason why some Japanese herpetologists don't accept Echinotriton, but I suspect it is due to relatively slight genetic differentiation, irrespective of morphological differences. I do know of other examples of salamanders in the same genus and even the same species being morphologically different but genetically similar, and vice-versa.

If you look at Japanese herpetological reports about andersoni since 1982, when it seems Echinotriton and Tylototriton were split), you'll see that most still place it in Tylototriton though some may add Echinotriton after that in brackets.

Ota, H. and Y. Obara (2004). Occurrence of the alligator newt, Tylototriton (Echinotriton) andersoni Boulenger, in the southern part of Okinawajima Island, Ryukyu Archipelago. Bull. Herpetol. Soc. Japan.

Hayashi, T., M. Matsui, T. Utsunomiya, S. Tanaka and H. Ota (1992). Allozyme variation in the newt Tylototriton andersoni from three islands of the Ryukyu archipelago. Herpetologica, 48.

Utsunomiya, T. and M. Matsui (2002). Male courtship behavior of Tylototriton (Echinotriton) andersoni Boulenger under laboratory conditions. Current Herpetology, 21(2).

Tanaka, Satoshi (1994). Preliminary observations on ecology of the subtropical newts Tylototriton andersoni and Cynops ensicauda in Sesokojima Island, the Ryukyu Islands. Okinawa J. Biol. Educ., Vol. 26.

Okinawa Prefecture Red Book (current)
http://www.pref.okinawa.jp/okinawa_kankyo/shizen_hogo/rdb/sp_data/i-01021.html

...among others

Ah, I just recalled something about this in a thread I started a couple of years ago, found at:

http://www.caudata.org/forum/messages/13/22650.html

The Goris & Maeda book (which I've subsequently found to have more than just a few mistakes in it!), has this to say:

"The genus Echinotriton was erected for this taxon (Nussbaum & Brodie, Herpetelogica, 38(2), 1982), but Japanese specialists argue that there is not enough genetic differentiation from Tylototriton to justify this."

There appears to be a discussion of this in the following report:

Hayashi, M. and M. Matsui, 1989. Preliminary�@study of phylogeny in the family Salamandridae: allozyme�@data. In: M. Matsui, T.�@Hikida, and�@R.C. Goris (eds.), Current�@Herpetology in East Asia, pp. 157-167. Herpetological Society of Japan, Kyoto.

Do you have this report?

I didn't want to hijack Ester's T. wienxianensus thread at:

http://www.caudata.org/forum/messages/13/64941.html?1148627907

...so I have started this new thread in response to the following exchange:

TIM: ...some Japanese scientists still don't accept Echinotriton as a genus distinct from Tylototriton.

WOUTER: The description of Echinotriton is completely valid to my opinion. It's nice to see that there is some taxonomical work done there in Asia concerning salamanders. The situation in Asia with all it's "species" and "forms" can't be compared with Europe or North America. Echinotriton seems like a good example to me, they really look different from Tylototriton sp.

(Message edited by TJ on May 26, 2006)

Hi Tim, nice thread... no I don't have that report. I'm a bit sceptical however about an allozyme research of the whole Salamandridae family. They would have to analyse many, many populations, mainly in Asia.

Chan et al 2001 (see below) is a great report, but it doesn't have any data about Tylototriton and Echinotriton. You can find that one on the internet.

Echinotriton with their unique headshape, unique middle ribs and small feet etc. are a real genus to me... Even their lifestyle is different for the most part from Tylototriton. I understand the Japanese too, however, because the Asperrimus complex is a bit of a taxonomical problem.
Do you think that the description of the genus without any help of Japanese scientists could have something to do with not accepting the genus?

Chan, L. M., K. R. Zamudio & D. B. Wake (2001) Relationships of the Salamandrid Genera Paramesotriton, Pachytriton, and Cynops Based on Mitochondrial DNA Sequences. Copeia 4: 997–1009

The answer lies in the phylogeny and genealogy of the species rather than the morphological differences/similarities. Animals that appear to be morphologically identical are sometimes found to be genetically different species. To my eyes there seems to be many similarities between the two genus, I can’t claim to have studied them in any detail though. There is clearly some sort of evolutionary relationship there but genetic evidence will determine how to shape that history and if they deserve their own genus. What do the Japanese scientists know that makes them sceptical? They should share their findings….

It's not only Japanese scientists and I don't think their genetic data is any secret. It might be in that report I mentioned above, which I'm trying to get

In China, Ermi Zhao and Qixiong Hu, in their 1988 book Studies on Chinese Salamanders, present their view that Echinotriton is just a subgenus of Tylototriton, (the genus Tylototriton being divided into subgenus Tylototriton and subgenus Echinitriton). They also view the "subgenus" Echinotriton to include asperrimus along with andersoni and chinhaiensis. They note that asperrimus has characteristics intermediate between Echinotriton and Tylototriton.

I've also got 'Studies on Chinese Salamanders' the view of Zhao is also completely morphological. T. asperrimus is to my opinion more Tylototriton-like, than Echinotriton-like.

Genetical research is as far as I know never thoroughly done within the Crocodile salamander genera. I've always thought that the Echinotriton species may have been isolated for thousands of years, maybe even through multiple ice ages.

And it's an ongoing discussion of course... If Mesotriton, Lissotriton and Ommatotriton are valid, why would't Echinotriton?

Wouter: well with Mesotriton, Lissotriton, Ommatotriton, and Triturus, the genetic evidence is clear.

There are plenty of example of genera where members display clear morphological differences and even life history differences but are still shown to be deeply nested within the genus with molecular data (Ambystoma opacum, Ambystoma annulatum/cingulatum, Desmognathus wrighti/aenues, etc.).

I haven't seen the genetic data on Echinotriton vs. Tylototriton yet, but I doubt the Japanese researchers are opposing the split without solid reasoning.

I should clarify my above remark about the genetic data not being any secret by noting that for andersoni, it's publicly available in the above-cited report Allozyme variation in the newt Tylototriton andersoni from three islands of the Ryukyu archipelago. I just haven't seen the data comparing andersoni with the Chinese species. Again, I've seen something that suggests to me it may be found, at least partially, in the report Preliminary�@study of phylogeny in the family Salamandridae: allozyme�@data.