Chromodoris collingwoodi or Chromodoris sp. 19 ????
Chromodoris sp. 19 Undescribed|
Indo-Pacific Nudibranchs and Sea Slugs
Well isn't this an interesting conundrum? Every once in a while we find two seemingly different species playing around and even copulating. In each case several question are raised: 1) could the animals be different color variants of an extremely variable species, and 2) do the two lay fertile eggs after their encounter? As has been discussed many times on Mike's site here and on the Sea Slug Forum, viable young are never produced from these unions.
That leaves the issue of color variation. The two animals in Mike's top photo are obviously Chromodoris collingwoodi and a species known only from Bali, one we call Chromodoris sp. 19 in Indo-Pacific Nudibranchs, page 226.
C. collingwoodi is a spectacular creature, but one with a very consistent coloration. Although we only have a couple sightings of Chromodoris sp. 19, they too show little variation. Mike's photo here, looking nearly identical to Mabel Fang's on page 226. Also note the difference in gill structure between the two.
So, those being the facts, we are left wondering what is going on here. Is this a game of push and shove, or what? Or is this just a coincidence, resulting in a healthy nudge. Mike didn't wait around to see if the two in fact mated, but regardless, no little hybrids would have been produced. I vote for coincidence.
WEBMASTER'S NOTES: What exactly is going on here must certainly be on every reader's mind! I have always wanted to make the encounter of Chromodoris sp. 19 after seeing Mabel Fang's photo in the Indo book! But as luck would have it, despite numerous trips to Bali-we never made each other's acquaintance until my trip this Jan. Not only did I get to see it on the first dive, but saw it repeatedly on successive dives, often in the company of what was readily identifiable as Chromodoris collingwoodi. They seemed on pretty familiar terms to say the least! Bali seems to be the only location where I have ever seen images of Chromodoris sp. 19! If our readers have seen it elsewhere Dave and I would certainly like to hear about it! A couple of short videos have been prepared for your enjoyment in both Windows Media 720p format and MPEG4 720p format for Macs.