An exploration of sufficient sampling effort to describe intraspecific DNA barcode haplotype diversity: examples from the ray-finned fishes

Estimating appropriate sample sizes to measure species abundance and richness is a fundamental problem for most biodiversity research. In this study, we explore a method to measure sampling sufficiency based on haplotype diversity in the ray-finned fishes (Animalia: Chordata: Actinopterygii). To do this, we use linear regression and hypothesis testing methods on haplotype accumulation curves from DNA barcodes for 18 species of fishes, in the statistics platform R. We use a simple mathematical model to estimate sampling sufficiency from a sample-number based prediction of intraspecific haplotype diversity, given an assumption of equal haplotype frequencies. Our model finds that haplotype diversity for most of the 18 fish species remains largely unsampled, and this appears to be a result of small sample sizes. Lastly, we discuss how our overly simple model may be a useful starting point to develop future estimators for intraspecific sampling sufficiency in studies using DNA barcodes.