Trapania sp.

Photo courtesy of Ali Hermosillo
Puerto Vallarta, Mexico
May, 2007

Trapania sp., undescribed

I took this picture last week during one of the best nudibranch dives I have had in Puerto Vallarta. I found 25 different species in one site. Among them was this Trapania , which I thought was Trapania goslineri until Dave saw my photo and told me that was one weird looking T. goslineri and that it was more likely an undescribed species of Trapania (Trapania sp. in Camacho et al., 2005) which Terry found at the Galapagos islands a while back. This was later on confirmed by Terry. Turns out seing this critter in Puerto Vallarta is quite an interesting new piece of information.

The genus Trapania is characterized by extra rhinophoral and branchial apendages, gill arranged in a semicircle and perfoliate rhinophores. The radula has two lateral teeth with no rachidian (central tooth).

There are four species of Trapania that have a white body and are known for the eastern Pacific. Trapania goslineri has large black spots and yellow tips in tail, extra rhinophoral and branchial appendages, gill plum and oral tentacles. Trapania velox has longitudinal black lines and yellow tips in the same appendages. Trapania inbiotica has redder spots, with red spots on rhinophores and yellow tips on the rest of the appendages. Trapania sp. has also red spots, but no yellow tips in either rhinophores or gill, which are white. Did I make it confusing enough for you??


Camacho García, Y.; Ortea, J. 2000-07/09. A new species of Trapania (Nudibranchia: Goniodorididae) from the Pacific coast of Central America. Revista de Biologia Tropical 48 (2-3): 317-322. [Trapania inbiotica n.sp.]

Field guide to the sea slugs of the tropical Eastern Pacific [in English and Spanish] / by Yolanda Camacho-Garcia, Terrence M. Gosliner & Angel Valdes. San Francisco : California Academy of Sciences, 2005.

Ali Hermosillo
Puerto Vallarta, Mexico
June, 2007

Puerto Vallarta, Mexico
March 2005

Ali Hermosillo and Dave Behrens

Author: Pacific Coast Nudibranchs
Co-Author Coral Reef Animals of the Indo Pacific
Proprietor of Sea Challengers Natural History Books

Send Dave mail at

© The Slug Site, Michael D. Miller 2007. All Rights Reserved.