Differences in the sensitivity among cryptic lineages of the Gammarus fossarum complex

doi:10.1016/j.scitotenv.2012.09.003

Science of The Total Environment

Volume 439, 15 November 2012, Pages 158-164

https://doi.org/10.1016/j.scitotenv.2012.09.003 Get rights and content

Abstract

Lineages that are at least superficially morphologically identical but genetically distinct are usually misclassified as a single nominal species and, hence, belong to a cryptic species complex, as for example observed for Gammarus fossarum. Since genetic differentiation between cryptic lineages of the G. fossarum complex is comparable to an interspecific level, deviations in physiological and behavioral characteristics are conceivable. The present study investigates for the first time deviations in the sensitivity between two cryptic G. fossarum lineages — namely lineage A and lineage B. Two size classes of both cryptic lineages were exposed in six independent experiments to different concentrations of the fungicide tebuconazole or the insecticide thiacloprid (each n = 20) for seven days. Feeding rate on leaf discs was used as a measure of sensitivity. By combining the outcome of all bioassays in a meta-analysis, cryptic lineage A showed – with an approximate 50% more pronounced decline in feeding – a significantly higher overall sensitivity compared to lineage B (n = 17). This was also obvious, when each chemical stressor was considered individually; however, data were not significant for thiacloprid. Although other reasons, like land-use of habitats around sampling sites and physiological characteristics of organisms, could not be excluded as driving factors, the results indicate that affiliation to a cryptic lineage is a potential explanatory variable for the observed deviations in sensitivity. As the present study considered only one population for each cryptic lineage, a final conclusion cannot yet be drawn. Hence, it is recommended to investigate behavioral and physiological deviations between cryptic lineages of the G. fossarum complex in further studies.

Highlights

► Genetic distance between cryptic lineages is comparable to an interspecific level. ► Differences in sensitivity between the two cryptic lineages exist. ► Affiliation to a cryptic lineage may explain differences in sensitivity.

Introduction

The taxonomic challenge of cryptic species complexes has been well known for approximately 300 years (Bickford et al., 2007). Cryptic lineages are morphologically not clearly distinct, but show considerable genetic differentiation and hence are misclassified as a single nominal species (Bickford et al., 2007). This genetic differentiation accumulated over time due to reproductive isolation among populations (Müller, 2000). Identification of cryptic lineages is further hindered as they may occur sympatrically.

Gammarus fossarum KOCH (Crustacea; Amphipoda; Gammaridae), a key species for the ecosystem function of leaf litter breakdown in circumneutral streams (Dangles et al., 2004), has split into at least three cryptic lineages, namely A, B and C (Müller, 2000), during or before the ice ages of the Pleistocene (about 2.4 mya) (Webb and Bartlein, 1992). The genetic differences between the three cryptic G. fossarum lineages are therefore comparable to an interspecific level (e.g. G. fossarum vs. Gammarus pulex) (Müller, 1998). Sensitivity towards chemical stress can vary considerably between species, for example shown for G. fossarum and G. pulex which exhibited 96h-LC50s of 1374 μg/L (Zubrod et al., 2010) and 1471–1745 μg/L (Adam et al., 2009), respectively, when exposed towards the fungicide tebuconazole. Therefore, deviations among cryptic lineages regarding physiological and behavioral characteristics are conceivable as well (cp. Bickford et al., 2007).

Hence, the present study investigates for the first time potential deviations in the sensitivity between two cryptic G. fossarum lineages – namely A and B – towards chemical stressors. Pure stands of both cryptic lineages were identified using two molecular markers: sequences of the 16S ribosomal RNA gene (16S rDNA) as well as the cytochrome oxidase subunit 1 (COXI) gene. Subsequently, the sensitivity of the cryptic G. fossarum lineages A and B was assessed towards pesticides with different modes of action, i.e. the fungicide tebuconazole (= 14-α-demethylase inhibitor) and the insecticide thiacloprid (= interaction with nicotine acetylcholine receptor). Moreover, two size classes were used for the bioassays since juveniles and adults of G. fossarum may exhibit different sensitivities towards pesticides (Adam et al., 2010). Feeding rate, a sensitive, robust and ecologically relevant endpoint (Maltby et al., 2002), was determined after seven days of exposure to different concentrations of each of the stressors in a total of six independent experiments. Furthermore, gammarids' initial lipid content as a factor potentially influencing their sensitivity towards chemical stress (Prato and Blandolino, 2009) was assessed. Finally, the results of all bioassays were combined using a meta-analysis to provide an overview of potentially unidentified differences in sensitivity between the two cryptic lineages of G. fossarum.

Section snippets

Sampling sites

Individuals of G. fossarum, intended to be used for genetic classification of cryptic lineages, were sampled randomly by kick sampling from an approximately 200-m stretch at three different sites. Two populations that have previously been specified to one of the cryptic lineages of G. fossarum were selected based on Müller (2000). The stream Weißklinge near Neuler (48°55′ N; 10°3′ E) and a stream near Sankt Johann (49°13′ N; 8°2′ E) are, according to Müller (2000), inhabited by pure stands of

Genetic classification

Out of 50 16S rDNA sequences from individuals of three populations, three different haplotypes were obtained, corresponding to the haplotypes B8, B9 and A15 published by Müller (2000). In the population sampled at Hainbach haplotypes B8 and B9 appeared, while in the populations from Sankt Johann and Weißklinge haplotypes B9 and A15, respectively, were detected. The ten COXI sequences were assigned to three different haplotypes as well, at which a different haplotype could be detected in each of

Conclusion

The conducted meta-analysis shows differences in the sensitivity of two cryptic G. fossarum lineages with a statistically significant higher sensitivity for lineage A (Fig. 1). Nevertheless, as the present study exclusively investigated differences in sensitivity towards two chemical stressors for populations from only one sampling site for each cryptic lineage, the present data needs to be interpreted with caution since the underlying mechanisms are presently unknown. Hence, further studies

Acknowledgments

The authors thank the Fix-Stiftung, Landau, for financial support of research infrastructure. Moreover, A. Engl, D. Englert, K. Storm, B. Thronicke and J. Zubrod are acknowledged for laboratory assistance. We are also grateful for chemical analysis by T. Bürgi and C. Stang. Furthermore, we thank S. Bub and M. Börder for their support during GIS-analyses. We acknowledge the valuable comments of F. Seitz, J. Zubrod and three anonymous reviewers on an earlier draft of the article. At last,

References (50)

O. Adam et al.
Mixture toxicity assessment of wood preservative pesticides in the freshwater amphipod Gammarus pulex (L.)
Ecotoxicol Environ Saf
(2009)
O. Adam et al.
High sensitivity of Gammarus sp. juveniles to deltamethrin: outcomes for risk assessment
Ecotoxicol Environ Saf
(2010)
C. Barata et al.
Biochemical factors contributing to response variation among resistant and sensitive clones of Daphnia magna Straus exposed to ethyl parathion
Ecotoxicol Environ Saf
(2001)
N. Berenzen et al.
A comparison of predicted and measured levels of runoff-related pesticide concentrations in small lowland streams on a landscape level
Chemosphere
(2005)
D. Bickford et al.
Cryptic species as a window on diversity and conservation
Trends Ecol Evol
(2007)
U. Borgmann et al.
Toxicity and bioaccumulation of thallium in Hyalella azteca, with comparison to other metals and prediction of environmental impact
Environ Pollut
(1998)
M. Bundschuh et al.
Ecotoxicologial evaluation of wastewater ozonation based on detritus-detritivore interactions
Chemosphere
(2011)
M. Bundschuh et al.
Fungal composition on leaves explains pollutant-mediated indirect effects on amphipod feeding
Aquat Toxicol
(2011)
D. Englert et al.
Thiacloprid affects trophic interaction between gammarids and mayflies
Environ Pollut
(2012)
J.H.E. Koop et al.
Towards environmental assessment of river ecosystems by analyzing energy reserves of aquatic invertebrates
Limnologica
(2008)

J.F.C. Malbouisson et al.

Use of feeding rate and re-pairing of precopulatory Gammarus pulex to assess toxicity of gamma-hexachlorocyclohexane (lindane)

Chemosphere

(1995)

C.P. McCahon et al.

Increased sensitivity to cadmium of the freshwater amphipod Gammarus pulex (L.) during the reproductive period

Aquat Toxicol

(1988)

J. Müller

Mitochondrial DNA, variation and the evolutionary history of cryptic Gammarus fossarum types

Mol Phylogenet Evol

(2000)

E. Prato et al.

Factors influencing the sensitivity of Gammarus aequicauda population from Mar Piccolo in Taranto (Southern Italy)

Ecotoxicol Environ Saf

(2009)

M. Rabiet et al.

Assessing pesticide concentrations and fluxes in the stream of a small vineyard catchment — effect of sampling frequency

Environ Pollut

(2010)

J.P. Zubrod et al.

Effects of subchronic fungicide exposure on the energy processing of Gammarus fossarum (Crustacea; Amphipoda)

Ecotoxicol Environ Saf

(2010)

D.G. Altman et al.

Statistics with confidence: confidence intervals and statistical guidelines

M. Borenstein et al.

Introduction to meta-analysis (statistics in practice)

(2009)

C. Chambon et al.

Sterol pathway in yeast. Identification and properties of mutant strains defective in mevalonate diphosphate decarboxylase and farnesyl diphosphate synthetase

Lipids

(1991)

C.K. Dang et al.

Magnitude and variability of process rates in fungal diversity-litter decomposition relationships

Ecol Lett

(2005)

O. Dangles et al.

Impacts of stream acidification on litter breakdown: implications for assessing ecosystem functioning

J Appl Ecol

(2004)

J.T.A. Dick

The cannibalistic behavior of 2 Gammarus species (Crustacea, Amphipoda)

J Zool

(1995)

J.T.A. Dick et al.

Intraguild predation may explain an amphipod replacement: evidence from laboratory populations

J Zool

(1999)

DIN 32645

Nachweis-, Erfassungs- und Bestimmungsgrenze

(1994)

A.K. Eriksson-Wiklund

Natural and pollution induced factors affecting the reproduction in amphipods

Department of Applied Environmental Science

(2002)

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Differences in the sensitivity among cryptic lineages of the Gammarus fossarum complex

Abstract

Highlights

Introduction

Section snippets

Sampling sites

Genetic classification

Conclusion

Acknowledgments

Ecotoxicol Environ Saf

Ecotoxicol Environ Saf

Ecotoxicol Environ Saf

Chemosphere

Trends Ecol Evol

Environ Pollut

Chemosphere

Aquat Toxicol

Environ Pollut

Limnologica

Chemosphere

Aquat Toxicol

Mol Phylogenet Evol

Ecotoxicol Environ Saf

Environ Pollut

Ecotoxicol Environ Saf

Statistics with confidence: confidence intervals and statistical guidelines

Introduction to meta-analysis (statistics in practice)

Sterol pathway in yeast. Identification and properties of mutant strains defective in mevalonate diphosphate decarboxylase and farnesyl diphosphate synthetase

Lipids

Magnitude and variability of process rates in fungal diversity-litter decomposition relationships

Ecol Lett

Impacts of stream acidification on litter breakdown: implications for assessing ecosystem functioning

J Appl Ecol

The cannibalistic behavior of 2 Gammarus species (Crustacea, Amphipoda)

J Zool

Intraguild predation may explain an amphipod replacement: evidence from laboratory populations

J Zool

Nachweis-, Erfassungs- und Bestimmungsgrenze

Natural and pollution induced factors affecting the reproduction in amphipods

Department of Applied Environmental Science