February 10, 2004
From: Debby Lange
Dear Dr Rudman,
I have found Hydatina albocincta in Merimbula Lake [New South Wales, Australia] a few times as an adult. On the 25th Jan, 2004, we found 2 along with 15 Hydatina physis. I have attached 2 photos of each of the above with eggs. Is Hydatina albocincta documented as being found here? Also, the Hydatina physis
that we found with eggs was a darker colour than the ones we found without eggs. Is this usual? (the photos show the true colours.)
[and the Sapphire Coast Marine Society]
firstname.lastname@example.orgLange, D., 2004 (Feb 10) Hydatina zonata in Merimbula, NSW. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12151
Thanks for these photos. As you'll see in a separate message [#12170] I consider Hydatina albocincta to be a synonym of the older Hydatina zonata. The shell is quite variable in colour pattern. Your photos are useful because they help illustrate how variable both H. zonata and H. physis are in colour of the animal has well, both species ranging from a pale almost colourless translucent white to a deep red. I wouldn't know if colour change is related to egg production but large animals of both species show quite a lot of colour variation so its unlikely. But it's something you could look at with the more plentiful H. physis.
Hydatina zonata is essentially a tropical species, but when conditions are favourable larvae can sometimes settle anywhere down the New South Wales coast. Wherever it is found, it does not seem to be as common as H. physis.
Hydatina zonata from Korea
From: Dong Bum Koh, December 12, 2005
How many species of Hydatina are there?
From: Bill Rudman, February 10, 2004
Re: Hydatina zonata from Japan
From: Nishina Masayoshi, August 13, 2001
Hydatina zonata from Japan
From: Nishina Masayoshi , August 10, 2001