scholarly journals An Investigation into Tetrodotoxin (TTX) Levels Associated with the Red Dorsal Spots in Eastern Newt (Notophthalmus viridescens) Efts and Adults

2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
Mackenzie M. Spicer ◽  
Amber N. Stokes ◽  
Trevor L. Chapman ◽  
Edmund D. Brodie ◽  
Edmund D. Brodie ◽  
...  
Keyword(s):  
Notophthalmus Viridescens ◽  
Eastern Newt ◽  
Pleurodeles Waltl ◽  
Surrounding Skin

We investigated the concentration of tetrodotoxin (TTX) in sections of skin containing and lacking red dorsal spots in both Eastern newt (Notophthalmus viridescens) efts and adults. Several other species, such as Pleurodeles waltl and Echinotriton andersoni, have granular glands concentrated in brightly pigmented regions on the dorsum, and thus we hypothesized that the red dorsal spots of Eastern newts may also possess higher levels of TTX than the surrounding skin. We found no difference between the concentrations of TTX in the red spots as compared to neighboring skin lacking these spots in either efts or adults. However, efts with more red dorsal spots had elevated TTX levels relative to efts with fewer spots.

Rapid Change in Life-Cycle Polyphenism across a Subspecies Boundary of the Eastern Newt, Notophthalmus viridescens

2011 ◽  
Vol 45 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Mizuki K. Takahashi ◽  
Yukiko Y. Takahashi ◽  
Matthew J. Parris
Keyword(s):  
Life Cycle ◽  
Rapid Change ◽  
Notophthalmus Viridescens ◽  
Eastern Newt

Eastern Newt (Notophthalmus viridescens) larvae alter morphological but not chemical defenses in response to predator cues

2014 ◽  
Vol 92 (4) ◽  
pp. 279-283 ◽  
Author(s):  
Kelly H. Brossman ◽  
Bradley E. Carlson ◽  
Amber N. Stokes ◽  
Tracy Langkilde
Keyword(s):  
Phenotypic Plasticity ◽  
Larval Stage ◽  
Species Interactions ◽  
Tail Length ◽  
Morphological Plasticity ◽  
Chemical Defenses ◽  
Notophthalmus Viridescens ◽  
Predator Cues ◽  
Eastern Newt ◽  
Larval Toxicity

Prey traits are often modified in response to exposure to predators, a phenomenon known as predator-induced phenotypic plasticity. Morphological plasticity in response to predator cues is well documented in amphibians; however, predator-induced chemical defenses have received relatively little attention. The Eastern Newt (Notophthalmus viridescens (Rafinesque, 1820)), which possesses tetrodotoxin—a toxin for chemical defense, is most vulnerable to predation during its larval stage. We assessed whether exposing Eastern Newt larvae to predator scent cues (from dragonfly larvae) would elicit change in their morphological and chemical defenses. Newt larvae exposed to scent cues of predatory dragonfly larvae exhibited significantly greater tail depths, which should increase survival of attempted predation by allowing them to swim faster, but did not differ in mass, snout–vent length, or tail length. Toxin concentrations in newt larvae were not significantly affected by exposure to these predator cues. Larval toxicity may be derived maternally or environmentally and is inflexible, or induced toxicity may only be detectable later in development. Predator-induced phenotypic plasticity, especially of chemical defenses, warrants greater attention, as potentially important outcomes of species interactions remain unclear.

Changes in the gut microbial community of the eastern newt (Notophthalmus viridescens) across its three distinct life stages

2021 ◽  
Vol 97 (3) ◽  
Author(s):  
Samantha S Fontaine ◽  
Patrick M Mineo ◽  
Kevin D Kohl
Keyword(s):  
Microbial Community ◽  
Community Assembly ◽  
Developmental Stages ◽  
Life Stage ◽  
Complex Life Cycle ◽  
Notophthalmus Viridescens ◽  
Selective Forces ◽  
Eastern Newt ◽  
Two Stages ◽  
Gut Microbial Community

ABSTRACT Understanding the forces that shape vertebrate gut microbial community assembly and composition throughout development is a major focus of the microbiome field. Here, we utilize the complex life cycle of the eastern newt (Notophthalmus viridescens) as a natural wild model to compare the effects of host and environmental factors on gut microbiome development. We compared bacterial inventories of each of the newt's three physiologically distinct developmental stages to determine if each hosted a unique community, or if the two stages which share an aquatic habitat (larvae and adults) harbored more similar communities than those of the third stage, the terrestrial juvenile eft. Additionally, we assessed how the contribution of selective processes to gut microbial assembly changed through development. We found that structurally, each life stage harbored a distinct community, which may be attributable to host factors. Further, across development, we found that community assembly processes shifted from a predominance of neutral to selective forces. However, habitat may also be important in determining community membership and diversity due the uniqueness of eft communities based on these metrics. Our results are similar to those in other vertebrate taxa, suggesting that gut microbiota assembly processes may be conserved across diverse lineages.

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