Grass carp (Ctenopharyngodon idellus) is a native Chinese cyprinid fish, the only species of the genus Ctenopharyngodon. It distributes from the catchment area of the Pearl River in southern China to that of the Heilongjiang River in northern China. As a herbivorous species, the grass carp consumes aquatic vegetation very fast and grows rapidly, so this fish has been introduced to many other countries to control undesirable aquatic vegetation. Due to its delicious flesh, the grass carp is broadly cultivated for food as one of the four major domestic fishes in China. To date, the yield of grass carp shares 16%, the biggest proportion among all aquatic economic fishes around the world.

The Grass Carp Genome Database (GCGD) is a curated web platform for centralized access to information on grass carp genome and genetics. The data cover assembled genome sequences, molecular markers, published high-throughput sequencing data, predicted genes and annotations from other databases including nr, Gene Ontology (GO) or KEGG. Comparisons of synteny between grass carp and zebrafish are also visualized. Some tools were integrated to facilitate the search and analysis of data, e.g. mapping by blast, slicing sequences, enriching KEGG and GO terms.

The genome of grass carp consists of 24 pairs of chromosomes, and it is one pair less than that of zebrafish due to a chromosome fusion during evolution. While a chromosome-level assembly is still on the way, GCGD is based the draft genome was published in 2015 as the result of collaboration of multiple research groups, which include: