Interspecific interactions between coexisting Siberian and Ezo salamander larvae examined by stable isotope analyses

Hokkaido Island is inhabited by two salamander species, Siberian salamander ( Salamandrella keyserlingii ) and Ezo salamander ( Hynobius retardatus ), which were previously considered incompatible to cohabit due to the predation and/or competition between them. Both species had never been seen repro...

Full description

Saved in:
Bibliographic Details
Published in:Limnology 2023-04, Vol.24 (2), p.111-119
Main Authors: Terui, Shigeharu, Furuta, Tsubasa, Kohmatsu, Yukihiro, Maruyama, Atsushi
Format: Article
Language:English
Subjects:
Aquaria
Aquarium fishes
Aquatic reptiles
Biomedical and Life Sciences
Distribution patterns
Ecological distribution
Ecology
Environment
Freshwater & Marine Ecology
Interspecific relationships
Isotope ratios
Isotopes
Larvae
Life Sciences
Microenvironments
Microhabitat
Microhabitats
Ponds
Population density
Predation
Predators
Prey
Reproduction (biology)
Research Paper
Salamandrella keyserlingii
Segregation
Species
Stable isotopes
Sympatric populations
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Hokkaido Island is inhabited by two salamander species, Siberian salamander ( Salamandrella keyserlingii ) and Ezo salamander ( Hynobius retardatus ), which were previously considered incompatible to cohabit due to the predation and/or competition between them. Both species had never been seen reproducing sympatrically until a recent discovery in a pond where the two species spawn concurrently. We investigated their potential interspecific interaction, by identifying the trophic niche of the coexisting populations in this pond using isotope analysis. We initially conducted aquarium experiments to determine the trophic discrimination factor (TDF) of main-body δ values, which are required to accurately interpret the isotope ratios in the field. The TDF of δ 15 N and δ 13 C were 1.6‰ and 0.1‰ for S. keyserlingii and 1.5‰ and 0.5‰ for H. retardatus , respectively. The δ 15 N and δ 13 C results from the pond in June suggested the possibility that H. retardatus larva may prey on S. keyserlingii larva, but this prey–predator interaction had subsided by July, if ever. Further, the interspecific variations in δ values suggested that the two species consumed different foods in July, when both species reached isotopic steady states. Thus, we conclude that the coexisting salamander larvae do not have continuous prey–predator or competitive interaction as expected from their exclusive distribution patterns. The unsustainable negative interspecificity may be avoided due to microhabitat segregation in the pond or by a decrease in the S. keyserlingii population density after predation.
ISSN:1439-8621
1439-863X
DOI:10.1007/s10201-022-00709-y