Species composition of massive fish eggs from mixed sample using DNA barcodes

Abstract

Fish eggs have been difficult to be classified into the species level by a conventional method because of the limit comparative morphological characteristics and the morphological change according to the developmental stage. The DNA does not change by development from eggs to adult. Fish eggs are able to be identified using the DNA. The species identification of fish eggs is to be tested for spawning ecology. It causes the high cost to analyze and needs hard work. Because of using a Sanger method, it is analyzed one sequence per one fish egg. To find the alternative method, we tried pyrosequencing to analyze the massive fish eggs in this study. The species composition of fish eggs is elucidated as pyrosequnecing based the DNA barcode of 16S rDNA. Fish eggs were collected weekly at four stations from May to August during 2008 to 2010 in the coastal rear of Yeosu. Anchovy eggs easily classified by morphological characters were excluded to increase the precision of the minor species in the result because anchovy eggs were dominated in the study area. The genomic DNAs were extracted from 100 mixed eggs per sample from each station. The 16S rDNA was partially amplified. The sequences were trimmed and analyzed by Mothur with the 16S rDNA reference data from the NCBI data and mine. We found the 60 species of fish eggs in the coastal area of Yeosu. The main period of appearance was from the late Js not change by development from eggs to adult. Fish eggs are able to be identified using the DNA. The species identification of fish eggs is to be tested for spawning ecology. It causes the high cost to analyze and needs hard work. Because of using a Sanger method, it is analyzed one sequence per one fish egg. To find the alternative method, we tried pyrosequencing to analyze the massive fish eggs in this study. The species composition of fish eggs is elucidated as pyrosequnecing based the DNA barcode of 16S rDNA. Fish eggs were collected we