Development of an Argopecten - Specific 18S rRNA targeted genetic probe

Comparison of 18S ribosomal RNA gene sequences between diverse bivalve spec ies, including eight scallop species, allowed the design of an 18S rRNA tar geted oligonucleotide probe (BS-1364) that tvas specific for scallops belon ging to the genus Argopecten (bay and calico scallops). The high sequence s imilarity of the 18S rRNA gene between Argopecten irradians and Argopecten gibbus (98.8%) prevented the design of an A. irradians species-specific pro be. Hybridization studies using amplified 18S rDNA from a diverse collectio n of bivalve species demonstrated that the specificity of the digoxygenin-l abeled probe was consistent with the predicted specificity indicated by seq uence comparison. Hybridization studies using laboratory-spawned bay scallo p veligers indicated that a single veliger could be detected by probe hybri dization in a blot format, and that probe hybridization signal was proporti onal (r(2) = .99) to the abundance of veligers. Methods for rRNA extraction and blotting were developed that allowed bay scallop veligers to be specif ically and quantitatively identified in natural plankton samples. Prelimina ry studies conducted in Tampa Bay, Florida, suggest that introduced scallop s can successfully spawn and produce veligers under in situ conditions. The Argopecten-specific probe and methods developed in this study provide the means to study the production and fate of bay scallop larvae in nature and provide evidence that scallops introduced into Tampa Bay have the potential for successful reproduction and enhancement of scallop stocks.