new Taqman© PCR-based method for the detection and identification of scyphozoan jellyfish polyps

• Published in: Hydrobiologia 2009, Vol.616 (1), p.217-228
• Main Authors: Bayha, Keith M, Graham, William M
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Barges; Biological and medical sciences; Biomedical and Life Sciences; Cnidaria. Ctenaria; Deoxyribonucleic acid; DNA; Ecology; Fouling; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; General aspects; Invertebrates; Jellyfish Blooms; Life Sciences; Marine biology; Nonnative species; Population distribution; Probes; Studies; Synecology; Translocation; Zoology
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-008-9590-y

While blooms of large scyphomedusae and cubomedusae receive most public attention owing to effects on tourism (e.g., stinging swimmers), commerce, and fisheries, relatively little attention is given to the inconspicuous benthic polypoid stage. This is particularly troubling when considering the widespread translocation of some invasive marine jellyfish. The transport of benthic polyps (via ships, barges, and offshore drilling platforms) is theorized to be the most likely way in which invasive jellies are globally transported. Yet given the extremely small size and cryptic nature of most benthic polyps, identifying and tracking them in the field amongst the larger communities of fouling organisms is extremely difficult. To this end, we have developed a rapid molecular assay for detecting benthic jellyfish polyps from three scyphozoan genera in the Gulf of Mexico. One of these (Phyllorhiza spp.) is an invasive scyphozoan established in the Gulf of Mexico and is theorized to have been spread worldwide as a fouling organism on the hulls of cargo ships, while the other two (U.S. Chrysaora sp. and Gulf of Mexico Aurelia spp.) are local blooming animals that have shown recent numerical increases in the Gulf of Mexico. This method involves a multiplex Real-Time Polymerase Chain Reaction (PCR) assay using Taqman© probes that can be run on DNA extracted from whole-community scrapings of benthic surfaces, such as boat hulls, dock pilings, oilrigs, and settling plates. Specificity tests indicated that all Taqman© probes were successful against all individuals of target taxa, but not against 17 non-target local and worldwide scyphozoan and hydrozoan species. Tests showed all probes to be extremely sensitive, reacting to as few as 50 copies of template DNA, with one (Chrysaora sp.) reacting to as few as 10 copies. The assay correctly identified individual polyps of Aurelia sp. and Chrysaora sp. The use of this Taqman© assay on tissue collected from whole benthic scrapings should allow screening of incoming ships to the Gulf of Mexico for the invasive P. punctata, and locating and studying the cryptic benthic stages of northern Gulf of Mexico jellyfish, which will lead to a better understanding of the overall population distribution and bloom dynamics of medusae.