Concepcion et al. 2010

scientific article | Mar Ecol Prog Ser

Resolving natural ranges and marine invasions in a globally distributed octocoral (genus Carijoa)

Concepcion GT, Kahng SE, Crepeau MW, Franklin EC, Coles SL, Toonen RJ


The first published report of the snowflake coral in Hawai‘i comes from Pearl Harbor in 1972; subsequent identification as the Caribbean octocoral Carijoa riisei led to the general conclusion that it was introduced to Hawai‘i from a Caribbean source. In an attempt to confirm the source of the Hawaiian population, we used mitochondrial (mtDNA) and nuclear (nDNA) sequence data to compare Hawaiian populations with samples of Carijoa (N = 244) collected worldwide. In addition, cumulative vessel traffic patterns from 1940-1979 were compiled for the Pacific Ocean to determine maritime connectivity to and from Hawai‘i during the assumed time of introduction. Carijoa sampled from throughout Hawai‘i (N = 94) share none of the Caribbean mtDNA haplotypes and only a single nDNA allele (0 of 28 and 1 of 27, respectively), indicating that the Hawaiian populations derive from Indo-Pacific rather than Caribbean-Atlantic origins. Furthermore, both mtDNA and nDNA show significant isolation-by-distance patterns overall and among the Pacific and Hawaiian sampling regions. These data indicate that Carijoa is native to the Indo-Pacific. Published reports of geographically wide-ranging invasions of Carijoa throughout the Pacific appear unfounded because our global sampling shows higher diversity in mtDNA (He= 0.87; ℀= 0.0023) and nDNA (D= 0.91; ℀= 0.042) through-out the Pacific relative to the Caribbean-Atlantic, indicating long evolutionary presence of Carijoa in the region. Our data clearly refute a Caribbean origin for Carijoa in the Hawaiian Archipelago, and indicate that the genus Carijoa is native to the Pacific and in need of further taxonomic evaluation.