First record of Phytomyxid infection of the non-native seagrass Halophila stipulacea in Puerto Rico

Halophila stipulacea is an invasive seagrass in the Caribbean Sea that also harbors a phytomyxid endoparasite. Phytomyxean parasites are known to cause disease in agricultural crops and are documented to form galls in some seagrass species. Here we make the first report of phytomyxid infection of Halophila stipulacea in the Bahía de Jobos in Salinas, Puerto Rico. We found phytomyxid infected H. stipulacea at 3 of 5 sites examined, expanding the documented range of the Marinomyxa marina phytomyxid infection by almost 400 km from where it was first documented in 2018. Presence of the endoparasite has not impeded H. stipulacea dispersal and continued expansion of H. stipulacea will likely spread both the host seagrass and the endoparasite.

Impact/Purpose

Although the non-native seagrass Halophila stipulacea has been previously reported, this is the first documentation of the phytomyxid endoparasite infection of the species in Puerto Rico.  Recognition of this parasitic infection highlights that two distinct species, the seagrass Halophila stipulacea and its endoparasite Marinomyxa marina have invaded Puerto Rico estuaries.  Previous reports of phytomyxid infected H. stipulacea in the Caribbean include Bonaire, Martinique and Saba.  Finding the phytomyxid in Puerto Rico supports the hypothesis that Marinomyxa marina is likely widespread throughout the Caribbean.  Further, it is likely that both species will continue to expand their range in the Caribbean and could also spread to systems in the Gulf of Mexico. 

Citation

Kaldy, J., C. Sullivan, A. Dieppa, I. Cappielo Cosme, M. Orizondo Lugo, AND M. Schiebout. First record of Phytomyxid infection of the non-native seagrass Halophila stipulacea in Puerto Rico. Walter de Gruyter GmbH, Berlin, GERMANYbot-2022-0074, (2023). [DOI: 10.1515/bot-2022-0074]

DOI: First record of Phytomyxid infection of the non-native seagrass Halophila stipulacea in Puerto Rico