Table 1.

Potentials and drawbacks for the traditional morphological and molecular genetic species identification in biodiversity analyses.

	potentials	drawbacks
morphological identification
	#information on —life stage composition and size class distribution —traits and hence ecological role/function —quantification (abundance, biomass)	#requires taxonomic expertise on diverse groups #incoherent species descriptions #gender- and stage-related diagnostic species characters #identification depends on condition of the organism #subjective nature of diagnostic characters #no identification of sibling and cryptic species and populations #time intensive
molecular genetic identification
single species	#species identification of young developmental stages and cryptic/sibling species → higher diversity #identification of populations #standardized identification, automation	#requires prior methodological knowledge
metabarcoding	#simultaneous identification of a multitude of species #processing of large numbers of samples #efficient and cost-effective for analysing bulk samples #standardized identification, automation	#no information on —community structure regarding size and stage distribution —biomass and abundance —ecological role #depends on high-quality sequence reference database for different regions and progress in providing sequence reference entries #identification of thresholds #false positives, false negatives #primer and PCR biases (amplicon sequencing)