Re: Thecacera pennigera from Woods Hole

December 5, 2006
From: Alan Shepard

Concerning message #11532:

Bill -
After not finding Thecacera pennigera at Woods Hole, Massachusetts, USA in either 2004 or 2005 after its initial appearance in 2003 it has reappeared in great numbers in 2006. A friend knowing of my interest in the species notified me of its return a few weeks ago and I got the chance to dive the area last week.

Locality: Woods Hole, 8 metres, Massachusetts, USA, Atlantic Ocean, November 30, 2006, soft bottom strewn with boulders. Length: 20mm. Photographer: Alan Shepard.

A good percentage of any hard substrate was covered with the bryozoan Bugula which in turn were covered in Thecacera pennigera and egg masses. I assume that somehow the species had maintained a foothold in the area but not in great numbers in either 2004 or 2005 and that conditions were just right for the population explosion in 2006.

Best wishes,
Alan Shepard
Tolland, CT

alan.chepard@snet.net

Shepard, A., 2006 (Dec 5) Re: Thecacera pennigera from Woods Hole. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18899

Dear Alan,
Thanks for keeping us up to date. It's interesting that all Atlantic records seem to be of this colour form with small orange spots and smaller dark blue specks. It also would be interesting to determine whether species like Thecacera, which appear irregularly like this, often in large numbers - apparently from nowhere, maintain a small foothold all the time, as you suggest, waiting for the food to appear in abundance, or whether they totally disappear after a 'boom'. Perhaps they reappear again as a larval swarm, travelling on a suitable current, and finding suitable food supplies, settle out of the plankton for another appearance. 'Population  explosion' implies that there was a resident low level population present. Perhaps what you are witnessing is the visit of a 'travelling circus'  which stops in your town when conditions are right and then moves on.
Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Dec 5). Comment on Re: Thecacera pennigera from Woods Hole by Alan Shepard. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18899

Factsheet

Thecacera pennigera

Related messages

  1. Re: Thecacera pennigera - a new Mediterranean exotic
    From: Constantine Mifsud, April 7, 2008
  2. Re: Thecacera pennigera - a new Mediterranean exotic
    From: Gary McDonald, April 1, 2008
  3. Re: Thecacera pennigera - a new Mediterranean exotic?
    From: Dani Barchana, March 27, 2008
  4. Re: Thecacera pennigera - a new Mediterranean exotic
    From: Juan Lucas Cervera, March 27, 2008
  5. Thecacera pennigera - a new Mediterranean exotic?
    From: Dani Barchana, March 26, 2008
  6. Thecacera pennigera from eastern Australia
    From: Leanne & David Atkinson, November 30, 2006
  7. Thecacera pennigera from South Australia
    From: Dennis Hutson, June 20, 2005
  8. Thecacera pennigera from Senegal
    From: Marina Poddubetskaia, June 20, 2005
  9. Additional record of Thecacera pennigera from Florida
    From: Jeff Goddard, May 5, 2005
  10. Thecacera pennigera laying eggs - Woods Hole
    From: Alan Shepard, December 4, 2003
  11. Thecacera pennigera from Woods Hole
    From: Alan Shepard, November 28, 2003
  12. Re: Thecacera pennigera from Woods Hole
    From: Colin Redfern, November 26, 2003
  13. Re: Thecacera pennigera from Woods Hole
    From: Alan Shepard, November 25, 2003
  14. Thecacera pennigera from Woods Hole, Massachusetts
    From: Alan Shepard, November 21, 2003
  15. Thecacera pennigera from Korea
    From: Dong Bum Koh, June 24, 2002
  16. Thecacera pennigera? from Japan
    From: Jun Imamoto, September 13, 2001
  17. Re: Colour variation in Thecacera pennigera?
    From: Loumar Wittebroodt, October 2, 1999
  18. Eggs of Thecacera pennigera
    From: René Lipmann, September 5, 1999
  19. Thecacera pennigera from the Netherlands
    From: René Lipmann, August 31, 1999
  20. Thecacera pennigera from the Netherlands
    From: Peter H. van Bragt, August 8, 1999
  21. Thecacera pennigera from New Zealand
    From: Ross & Diane Armstrong, July 24, 1999
  22. Re: Thecacera pennigera?
    From: David W. Behrens, April 8, 1998
  23. Re: Thecacera pennigera?
    From: Bernard Picton, March 26, 1998
  24. Thecacera pennigera?
    From: David & Leanne Atkinson, December 19, 1997

Show factsheet and all related messages