<i>H. tokyoensis</i> sexual dimorphism?

J

jennifer

Guest
I obtained 6 CB juvenile H. tokyoensis about 6 months ago. I believe that all looked similar at the time I received them, but now one of them is much larger and lighter colored. The other 5 still look very similar.

Is it likely that the large one is female, and the others male? Or is it possible that there was a mix-up and the large one is H. dunni (which was part of the same import)? Or is it possible that they will all become lighter colored as they grow up, and this one is simply the "porker" of the bunch?

 
C

cameron

Guest
I don't know but I think it has to do with age. Some sals like P. ruber loose their bright color as they get older. Just a guess.
 

TJ

New member
Joined
Oct 26, 2002
Messages
4,471
Reaction score
0
Points
0
Location
Tokyo
Country
United States
Display Name
Tim Johnson
Jen, it seems to me that most of your juvenile H. tokyoensis are still showing their typical juvenile pattern and coloration, while the "porker" is either a bit older or has simply developed faster. Were the all the same size when you got them? Juveniles of most if not all hynobiid species of eastern and northern Honshu look pretty much the same to the casual observer, being speckled like that all over the dorsum (including H. tokyoensis, H. lichenatus, H. nigrescens). Then over time the speckles fade away from the top part of the dorsum but speckling of a sort remains on the lower part of the sides.

I'm not aware that coloration is any way of determining sex -- usually one goes by body size and shape, tail shape, and appearance of the cloaca (though I'm no good at this). As you can see by the following picture, there's quite some variation in H. tokyoensis coloration even among those gathered in the same pond during breeding season.


(this is an old photo that I'd posted before)

As for telling male hynobiids apart from females, it's always best to wait for the breeding season when differences are most apparent. Here's something to refer to (though not strictly as the species are different from H. tokyoensis):

http://www5d.biglobe.ne.jp/~hasumi/photo/vent_e.html

http://www5d.biglobe.ne.jp/~hasumi/photo/hh_aquatic_e.html

http://www5d.biglobe.ne.jp/~hasumi/photo/fem_e.html

http://www5d.biglobe.ne.jp/~hasumi/photo/hh_f_cloaca_e.html

(Message edited by TJ on April 21, 2007)
 

michael

2010 Research Grant Donor
Joined
Apr 12, 2003
Messages
3,270
Reaction score
74
Points
48
Location
Ephrata,Pa
Country
United States
Display Name
Michael Shrom
If I remember correctly the juvenile tokyoensis and dunni look similar but act different. I think the tokyoensis are the jumpy ones. I'm 95% sure you have all tokyoensis.
 
J

jennifer

Guest
Thank you for all the good info, Tim!
I remember that photo, but had never given any thought to the color variation among the animals. I think my porker may simply be headed toward being one of the lighter colored ones. At this point, he/she is very different looking from the others, but I think it's just a size difference. I haven't tried to examine cloacas, but I suspect it's too soon to tell a difference; those photo links are excellent.
 

TJ

New member
Joined
Oct 26, 2002
Messages
4,471
Reaction score
0
Points
0
Location
Tokyo
Country
United States
Display Name
Tim Johnson
Sure thing


And as Michael suggested, there are behavioral differences. Put a worm in front of its mouth and if it immediately grabs the worm and swallows it down like there's no tomorrow, it's probably an H. dunni. If it's skittish to begin with and reacts cautiously to being hand-fed, it's probably an H. tokoyoensis ... though I suppose H. tokyoensis become "tamer" over time (I've never kept adults, just raised some from egg sacs to the juvenile stage and given them away).

As for those links, yeah, they're nice. I wasn't aware before that the cloacal opening changes from a slit into a hole before egg sacs are laid. I wonder if this applies to all members of Hynobius...
 
General chit-chat
Help Users
  • No one is chatting at the moment.
  • AlexisJG:
    As long as they don’t seem stressed that’s good and I mean hey if their well fed maybe they’ll live long happy lives together.
    +2
    Unlike
  • HalfDrunkToast:
    oh ya they are happy xD every time i come in to my room my Koy betta is like HI HI HI and actively swimming around
    +1
    Unlike
  • Chat Bot:
    Calgarycoppers has left the room.
    +1
    Unlike
  • Nerodia1:
    Děkuji za přijetí. Hledám tohoto obojživelníka, Typhlonectes compressicauda, nevíte, kde ho získat, nejlépe někde v Evropě.
    +1
    Unlike
  • Chat Bot:
    Caudex has left the room.
    +1
    Unlike
  • Chat Bot:
    VEEK has left the room.
    +1
    Unlike
  • Lanalotl:
    My axie is acting woerd he was a rescue as stated in a different post he got better and now seems to be deteriorating again...again all tank conditions are OK and as should be. He seems to have some black dapple like pattern under his bottom lip? Is that normal? And his two back feet have a little wierd growth? Almost? Tiny tiny tiny lump. His capillaries in his feathers also appear darker and more visible. Any help would be appreciated
    +1
    Unlike
  • Lanalotl:
    Hes a leucistic axie
    +1
    Unlike
  • Chat Bot:
    AmphibiGirl has left the room.
    +1
    Unlike
  • Dibgame:
    Hey guys. First time on this forum and im not sure what formatting i should use but hey here i go.
    +1
    Unlike
  • Jadezoey:
    Hi! I'm being in a hard position where I have to re-home my axolotls. I'm moving out and I would like to find them a new home with someone who can take proper care of them
    +1
    Unlike
  • Jadezoey:
    I have an adult wild type and a juvenile leucistc
    +1
    Unlike
  • Unlike
  • BigAl:
    Oops my bad accidentally sent that
    +1
    Unlike
  • Binditheaxolotl:
    @HalfDrunkToastLol
    +1
    Unlike
  • AxieMomma87:
    is anyone online???
    +1
    Unlike
  • Chat Bot:
    Calgarycoppers has joined the room.
    +1
    Unlike
  • Unlike
  • Chat Bot:
    Calgarycoppers has left the room.
    +1
    Unlike
  • AxieMomma87:
    Are you still here
    +1
    Unlike
  • ZayneSantos:
    Is there anyone on who can give me advice?
    +1
    Unlike
  • Max2445:
    @ZayneSantos, What advice do you need
    +1
    Unlike
  • KrabzAga:
    based on this video what type of salamander might this larva be? I suspect either eastern newt or spotted salamander
    +1
    Unlike
  • KrabzAga:
    help appreciated
    +1
    Unlike
  • KrabzAga:
    they are from missouri
    +1
    Unlike
    KrabzAga: they are from missouri +1
    Top