Sex-biased Predation on Newts of the Genus Taricha by a Novel Predator and its Relationship with Tetrodotoxin Toxicity

作者：Stokes Amber N^*; Cook David G; Hanifin Charles T; Brodie Edmund D III; Brodie Edmund D Jr

来源：American Midland Naturalist, 2011, 165(2): 389-399.

DOI：10.1674/0003-0031-165.2.389

Newts of the genus Taricha have long been studied in regards to their skin toxin, tetrodotoxin (TTX). It has been shown that the TTX levels across populations of Taricha are highly variable, and this has been mostly attributed to the interaction between Taricha and their only documented predators, garter snakes of the genus Thamnophis. Here we show that predators other than Thamnophis prey extensively on some newt populations. Ledson Marsh in Annadel State Park in Santa Rosa, CA is a breeding ground for both the California newt (Taricha torosa) and the rough-skinned newt (Taricha granulosa). Predation on these newts was tracked from 1998-2009 and was most often in the form of evisceration and significantly male-biased. As TTX seems to have been developed as an antipredator defense in Taricha, we used Fluorometric High Phase Liquid Chromatography (HPLC) analysis to quantify TTX levels in the skin of ten male and ten female newts of each species to determine the influence that TTX levels may have on sex-biased predation in this population. We found Taricha females were not significantly more toxic than males. Also, we found that T. torosa were significantly more toxic than T. granulosa, which is in contrast with other newt toxicity studies.

• 出版日期2011-4