The Gracilariaceae is a small family of red algae, containing several genera of agarophytes. It has a cosmopolitan distribution, in which 24 species are found in China, six in Great Britain and Ireland, and some in Australia and Chile.

They are normally found in intertidal bays, backwaters, and estuaries.

The family have been extensively investigated over the last 30 years, and various studies have yielded comprehensive information on their life history, cultivation, taxonomy, and utilization (Bellorin et al. 2002, Rueness 2005). Studies on the structure of their reproductive organs and the phylogenetic relationships among species inferred from rbcL sequence analyses have produced three clades at the genus level, namely Gracilaria, Gracilariopsis, and Hydropuntia (Gurgel and Fredericq 2004).

In 2012, the University of São Paulo, Brazil set up the Gracilariaceae Germplasm Bank, to use molecule markers for the identification of species.

...