Re: Introduced Philine in California

March 8, 1999
From: Michelle Chow

Bill,
Sorry for my late reply.  Unfortunately Terry is on vacation for this month and would have been able to provide you with the pictures he has taken so far; however let me try to fill you in.

Terry now believes that we have four different introduced species of Philine: Philine aperta from South Africa, P. japonica from Japan, P. orientalis from Hong Kong or Malaysia, and P. auriformis from New Zealand.  From my understanding, he is basing this information on gizzard plates, penial morphology, and shell sculpturing (among other things).  Philine auriformis has three equal sized gizzard plates with two longitudinal grooves on each plate, whereas the other three species of Philine have two larger and equally sized gizzard plates with two small holes in the center of each plate, and one smaller plate. Philine auriformis, P. aperta, and P. orientalis have a smooth surface on the outside of their shells, whereas the outer surface of P. japonica's shell is punctate.  As far as the penial morphology goes, it would probably be best to get the details from Terry.  All I know for sure is that all four morphologies are different. 

As for myself, I have been keeping busy investigating the distribution and abundance of Philine in San Francisco and Bodega Bay. P. auriformis and P. orientalis were very abundant in Bodega Bay in late spring/summer and have been slowly dying out over the fall and winter. However just last weekend I found the first young of the year Philine orientalis weighing in at 0.3 gr.  It will be interesting to watch what happens in the next couple of months.  

I also have been investigating the impact of Philine auriformis and Philine orientalis on the density of small bivalves on the Bodega Bay mudflats.  I am currently collecting data on enclosure experiments that I performed last summer.

So that is the story so far although I am sure that Terry would have more to tell you.  Terry has really been looking at the morphological differences between the Philine species whereas I have focused on the ecological impacts these introduced species might have on our mudflat fauna.  However because there is still some lingering confusion on which species we may have in California, I am planning to use genetic techniques to complement the morphological comparisons.  I would like to compare what we have in California to known specimens of P. auriformis, P. orientalis, P. aperta, and P. japonica from their native regions.  Therefore I would like to ask you if this information could be posted on your web page.

Currently I have no/few contacts to researchers in Japan, Malaysia, New Zealand, and South Africa.  I am hoping that perhaps interested researchers in these areas might be able to send known examples of these species of Philine.  Anyone interested should feel free to contact me through email at mmchow@ucdavis.edu

If you have any other questions, please let me know.  I was happy to get an email from you and will continue to send along information as it comes along.  I hope in a few weeks to give you an update on the enclosure experiments after I have had time to look at the data.

Cheers
Michelle Chow  

mmchow@ucdavis.edu

Chow, M., 1999 (Mar 8) Re: Introduced Philine in California. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/653

Copyright © Australian Museum, 1998-2010