While I was in Bali I shot a pleasing sequence of triplefins mating. These are an interesting species because they show pronounced sexual dimorphism. The male has a long nose and when mating has really bright display colours (although when viewed from above they remain camouflaged). The female is pretty drab.
But I am not sure of the ID. Can anyone help? I have always called them Rhino Triplefins, but i don't remember where I got that name from. I couldn't find them in any of the books at the resort, nor in any of my books at home.
Anyway, because I think that this is an interesting sequence, I know I'll need the ID at some stage...
Alex
Tough one Alex, I talked to Jack Randall about this group not long ago and he said there are many undescribed species. Do you have a shot showing the configuration of the fins? Open fins would help the ID a lot, doesn't need to be mating. How big were they?
Luiz
Here are some more photos
Alex
They were small. Less than an inch.
I photographed them early in the morning as I had just done a deep dive to photograph Coleman's Shrimps. I used the 105mm VR and a 5T dioptre.
Hopefully some of the other shots show the fins better.
Alex
Yes, much better, I will forward them to Jack Randall and wait for his comments. But let me tell you, I smell undescribed species on this one...
Luiz
Thanks Luiz.
Maybe on the undescribed front - being a small fish that lays eggs living in the complex geography (divided by Pacific overflow currents) of SE Asia is a likely scenario for speciation.
But I am sure that they are very similar to something that has been described. And being Bali this may well be one of the described species from the group. I have photographed them many times, just not mating.
Alex
I like the name Rhino to go along with that nose !
There is a photo in Reef Fish ID that looks like the male, Rhinoceros triplefin, Helcogramma rhinoceros. Range is spot on.
Cheers,
Marli
Could this be the as yet undiscovered 'Mustard triplefin' ?
I like the name Rhino to go along with that nose !
There you go, Helcogramma rhinoceros, I agree. Jack didn't know what species it was either, but he said it was on the genus Helcogramma. Noe that I am in my office and have access to more books, here is what I found out about it:
"Males are easily recognized by the extended nose and change color to display to females with an electric blue line below the eye, shaded by black below".
These are great photos of a poorly known species, that's why I like this critter ID forum so much...
