Hypselodoris sagaminensis from southern Queensland

Thanks Gary,

I was 'up to speed' on your finds of H. sagamiensis in southern Queensland, from your book, but I needed a photo or message to add it to the Forum. I wish I had time to search all the other excellent websites to pick up new distribution records but as you no doubt realise, I don't. When I said it was only known from the north west Pacific I was thinking in terms of what I was considering to be its 'natural' distribution.

The presence of H. sagamiensis in eastern Australia is interesting in itself, and it reminds me of H. maritima, which for a long time was known only from Japan and eastern Australia. As I mentioned recently [message #18625]  there was some thought that its presence in Australia was due to shipping, but we now have a number of records from places in between, suggesting it may be naturally found all through the western Pacific. At present H. sagamiensis seems to have a similar distribution in the north west Pacific and eastern Australia. It will be interesting to see if it begins to turn up in the tropical Pacific between these two regions.

Another equally interesting possibility is that H. sagamiensis is a colour form of H. maritima. Much of the basic pattern of the two species is the same, the main difference being that the longitudinal lines in H. maritima are replaced by spots in H. sagamiensis. However if we look at an earlier message from Erwin Koehler [#13910], it seems that H. maritima can have black spots instead of lines.

Thanks for sending the photos, they certainly reminded me of your find, and hopefully they have opened up an interesting line of investigation
Best wishes,
Bill Rudman