Possible Aplysia vaccaria from Santa Catalina Island

July 31, 2006
From: Amber Purohit


This weekend I had the great joy of stumbling across a giant sea hare while diving. I had never seen one this large. I estimate his length to be 60 - 70 cm. He was extremely active and curious. He lumbered around munching on kelp (see 1 of the 3 images) and even came right up to my camera to take a closer look at me. I stayed with him for about 30 minutes because I found him so fascinating. At first I thought he was Aplysia californica, but reading on your website I learned the only difference between A. californica and A. vaccaria is that A. californica produces purple ink when agitated. I know I startled him at least twice, and there was no ink release. This coupled with his extremely large size led me to believe it was indeed Aplysia vaccaria, but I welcome any insight you might have. What a wonderful joy though to spend just half an hour watching this uncoordinated and curious creature! I apologize for the particulate matter in the pictures, but he was particularly active, which led to lots of sediment in the photos.

Locality: Santa Catalina Island, 50 feet, California, USA, Pacific Ocean, 23 July 2006, Kelp Forest. Length: 60 - 70 cm. Photographer: Amber Purohit.

Amber Purohit

seaslugchick@verizon.net

Purohit, A.L., 2006 (Jul 31) Possible Aplysia vaccaria from Santa Catalina Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17246

Dear Amber,

There is not a lot known about this species,  but Behrens & Hermosillo (2005) report that it grows up to 99 cm in length, feeds primarily on the brown alga Egregia in kelp beds, and does not produce purple ink. They describe its colour as 'uniform dark brown to black ... sometimes with fine grey or white markings'.

I suspect you are correct in identifying your animal as A. vaccaria rather than A. californica, but would be grateful for feedback from local experts. Sea hares are sometimes difficult to identify from photos. If I can get a confirmation, I will at last have a photo of this species for the Fact Sheet

Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Jul 31). Comment on Possible Aplysia vaccaria from Santa Catalina Island by Amber Purohit. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17246

Factsheet

Aplysia vaccaria

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