Monitoring an Alien Invasion: DNA Barcoding and the Identification of Lionfish and Their Prey on Coral Reefs of the Mexican Caribbean

BACKGROUND: In the Mexican Caribbean, the exotic lionfish Pterois volitans has become a species of great concern because of their predatory habits and rapid expansion onto the Mesoamerican coral reef, the second largest continuous reef system in the world. This is the first report of DNA identification of stomach contents of lionfish using the barcode of life reference database (BOLD). METHODOLOGY/PRINCIPAL FINDINGS: We confirm with barcoding that only Pterois volitans is apparently present in the Mexican Caribbean. We analyzed the stomach contents of 157 specimens of P. volitans from various locations in the region. Based on DNA matches in the Barcode of Life Database (BOLD) and GenBank, we identified fishes from five orders, 14 families, 22 genera and 34 species in the stomach contents. The families with the most species represented were Gobiidae and Apogonidae. Some prey taxa are commercially important species. Seven species were new records for the Mexican Caribbean: Apogon mosavi, Coryphopterus venezuelae, C. thrix, C. tortugae, Lythrypnus minimus, Starksia langi and S. ocellata. DNA matches, as well as the presence of intact lionfish in the stomach contents, indicate some degree of cannibalism, a behavior confirmed in this species by the first time. We obtained 45 distinct crustacean prey sequences, from which only 20 taxa could be identified from the BOLD and GenBank databases. The matches were primarily to Decapoda but only a single taxon could be identified to the species level, Euphausia americana. CONCLUSIONS/SIGNIFICANCE: This technique proved to be an efficient and useful method, especially since prey species could be identified from partially-digested remains. The primary limitation is the lack of comprehensive coverage of potential prey species in the region in the BOLD and GenBank databases, especially among invertebrates

Keynote: “Georgia’s Logistics Ecosystem”

Keynote Addres

Applying the design structure matrix and critical chain methodologies to a technology-development project

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 1999.Includes bibliographical references (p. 65).In today's global economy, enterprises must develop higher-quality products at -an ever-increasing pace to remain competitive. This need drives project managers to seek new ways to organize and manage their development projects. Two means by which the cycle time of projects may be reduced are the Design Structure Matrix and Critical Chain methodologies. The Design Structure Matrix is a representation that makes explicit the dependencies between project tasks and in so doing clarifies how the tasks may be sequenced to avoid unnecessary, time-wasting iterations. The Critical Chain is a project-scheduling and -management methodology that recognizes that each project task is subject to uncertainty and accommodates that uncertainty in a way that protects the completion date of the project and hence minimizes its duration. While application of these techniques individually to product-development . projects has been reported in the literature, there are no reports of their application either together or to technology-development projects. That they have not been applied together is surprising, because the two methods complement each other. That they have not been applied to technology-development projects is surprising, too, because such projects have many similarities to product-development projects, and the same modern needs for cycle-time reduction. Accordingly, this thesis examines the feasibility of the application of the Design Structure Matrix and Critical Chain methodologies together to a technology-development project. The project is a four-month-long subproject of a magnetic-recording technology-development project, involving five people from two different organizations in the same company and an extern.al supplier. The major finding of the thesis work is that it is feasible to apply the two techniques together to a technology-development project-but to do so requires a high level of flexibility on the part of the Project Manager. Additional findings include guidelines for: creating the Design Structure Matrix as a team; choosing team members on the basis of their ability to implement the Critical Chain principles; and dealing with the constant flux in the task list that is inherent in technology development.by David C. Markham.S.M