August 16, 2007
From: Kevin Lee
Bruce Wight's recent parasite post reminded me of some infestations I've witnessed on Navanax. I was was wondering if Navs, when afflicted with parasites, purposely "expose" themselves, [see middle photo] in the hope that a fish or crab might come by and clean off the offenders. I watched this Nav for five minutes and, all the while, it had its mantle flared out.
All three fotos were taken in La Jolla Canyon.
Locality: La Jolla, 65 feet, California, USA, Eastern Pacific. Upper: 03 Sep 2005. Middle: 27 July 2007. Lower: 15 Oct 2006. Sandy bottom. Length: 7 cm. Photographer: Kevin Lee.
firstname.lastname@example.orgKevin L., 2007 (Aug 16) Parasites and Navanax inermis . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20446
I have looked at these photos rather hard and I think there is quite a bit of damage to the posterior end of the animals in the upper two photos. There are definitely copepods crawling over the skin but I think they are probably normal commensals.
In the upper photo there are two animals, the one on the right looks intact, but the one at the back seems to have the mantle organs missing - the shell, the gill, etc just aren't there. In the middle photo the 'flaring' bit at the top of the photo, with the copepods on it, is the foot, so the animal is upside down. The whitish 'sausage'-shaped structure in the middle is almost certainly the mucus gland section of the reproductive system, but that should be obscured by the large gill. Both the gill and the dorsal part of the posterior shield containing the shell appear to be absent. I think any 'itchiness' caused by the copepods is the least of these animal's concerns. My guess is there is something in the Canyon with a liking for the back end of Navanax. If you see an animal like this again try a bit of gentle poking and prodding to see if it is all there.
Thanks for the lower photo. One thing that does seem to differentiate Navanax from other aglajids are the elaboration of the pads on either side of the mouth which house the sensory bristles. In Navanax they have become curved ridges which are so clearly visible in your photo.
Re: Parasites and Navanax inermis
From: Ernie Hartt, September 25, 2007
Re: Parasites and Navanax inermis
From: Kevin Lee, August 17, 2007
More on Navanax inermis
From: Kevin Lee, August 16, 2007
Re: Navanax inermis mucus cocoon
From: Ernest Hartt, August 15, 2007
Might this be Navanax inermis?
From: Ken Tucker, August 14, 2007
Swimming Navanax from central California
From: Ron Eby, August 6, 2007
Navanax inermis laying eggs
From: Bruce Wight, July 28, 2007
Navanax inermis mucus cocoon
From: Phil Garner, May 23, 2007
Trail following in Navanax inermis
From: Ernest Hartt, August 29, 2006
Navanax - Aplysia interactions
From: William G. Wright, April 7, 2006
Navanax eating Aplysia
From: Brad Bartczak, September 17, 2005
Is this Navanax?
From: Peter McGuinness, December 28, 2004
Re: Strange lunch for Navanax
From: Ernie Hartt, December 18, 2003
Strange lunch for Navanax
From: Bruce Wight, November 15, 2003
Navanax - yellow secretions
From: Tammy, October 13, 2003
Navanax inermis from Long Beach, California
From: Crystal, April 30, 2003
Re: Navanax larval culture
From: Bill Rudman, March 21, 2002
Larval development of Navanax
From: I.M. Loeza & A.M. Ortiz, March 19, 2002
More photos of Navanax inermis
From: Daniel Geiger, July 29, 2001
Some photos of Navanax inermis
From: Daniel Geiger, July 27, 2001
Predators of Navanax inermis
From: Shannon, March 10, 2001
Cannibalism in Navanax inermis
From: Ernie Hartt, February 19, 2001
From: Vincent A. Parsick III, January 27, 2001
From: Erwin Koehler, October 3, 1998