Strategic considerations for invasive species managers in the utilization of environmental DNA (eDNA): steps for incorporating this powerful surveillance tool.

Invasive species surveillance programs can utilize environmental DNA sampling and analysis to provide information on the presence of invasive species. Wider utilization of eDNA techniques for invasive species surveillance may be warranted. This paper covers topics directed towards invasive species managers and eDNA practitioners working at the intersection of eDNA techniques and invasive species surveillance. It provides background information on the utility of eDNA for invasive species management and points to various examples of its use across federal and international programs. It provides information on 1) why an invasive species manager should consider using eDNA, 2) deciding if eDNA can help with the manager's surveillance needs, 3) important components to operational implementation, and 4) a high-level overview of the technical steps necessary for eDNA analysis. The goal of this paper is to assist invasive species managers in deciding if, when, and how to use eDNA for surveillance. If eDNA use is elected, the paper provides guidance on steps to ensure a clear understanding of the strengths and limitation of the methods and how results can be best utilized in the context of invasive species surveillance.

A microbial factory for defensive kahalalides in a tripartite marine symbiosis.

Chemical defense against predators is widespread in natural ecosystems. Occasionally, taxonomically distant organisms share the same defense chemical. Here, we describe an unusual tripartite marine symbiosis, in which an intracellular bacterial symbiont ("Candidatus Endobryopsis kahalalidefaciens") uses a diverse array of biosynthetic enzymes to convert simple substrates into a library of complex molecules (the kahalalides) for chemical defense of the host, the alga Bryopsis sp., against predation. The kahalalides are subsequently hijacked by a third partner, the herbivorous mollusk Elysia rufescens, and employed similarly for defense. "Ca E. kahalalidefaciens" has lost many essential traits for free living and acts as a factory for kahalalide production. This interaction between a bacterium, an alga, and an animal highlights the importance of chemical defense in the evolution of complex symbioses.

Draft Genome Sequence of Hawaiian Sea Slug Symbiont Vibrio sp. Strain ER1A.

Bacteria belonging to the genus Vibrio are prevalent in the marine environment and are known for forming symbiotic relationships with hosts. Vibrio sp. strain ER1A is a dominant symbiont of the Hawaiian sea slug, Elysia rufescens. Here we report the draft genome sequence of Vibrio sp. ER1A.

Integration of culture-based and molecular analysis of a complex sponge-associated bacterial community.

The bacterial communities of sponges have been studied using molecular techniques as well as culture-based techniques, but the communities described by these two methods are remarkably distinct. Culture-based methods describe communities dominated by Proteobacteria, and Actinomycetes while molecular methods describe communities dominated by predominantly uncultivated groups such as the Chloroflexi, Acidobacteria, and Acidimicrobidae. In this study, we used a wide range of culture media to increase the diversity of cultivable bacteria from the closely related giant barrel sponges, Xestospongia muta collected from the Florida Keys, Atlantic Ocean and Xestospongia testudinaria, collected from Indonesia, Pacific Ocean. Over 400 pure cultures were isolated and identified from X. muta and X. testudinaria and over 90 bacterial species were represented. Over 16,000 pyrosequences were analyzed and assigned to 976 OTUs. We employed both cultured-based methods and pyrosequencing to look for patterns of overlap between the culturable and molecular communities. Only one OTU was found in both the molecular and culturable communities, revealing limitations inherent in both approaches.

Characterization of the bacterial community of the chemically defended Hawaiian sacoglossan Elysia rufescens.

Sacoglossans are characterized by the ability to sequester functional chloroplasts from their algal diet through a process called kleptoplasty, enabling them to photosynthesize. The bacterial diversity associated with sacoglossans is not well understood. In this study, we coupled traditional cultivation-based methods with 454 pyrosequencing to examine the bacterial communities of the chemically defended Hawaiian sacoglossan Elysia rufescens and its secreted mucus. E. rufescens contains a defense molecule, kahalalide F, that is possibly of bacterial origin and is of interest because of its antifungal and anticancer properties. Our results showed that there is a diverse bacterial assemblage associated with E. rufescens and its mucus, with secreted mucus harboring higher bacterial richness than entire-E. rufescens samples. The most-abundant bacterial groups affiliated with E. rufescens and its mucus are Mycoplasma spp. and Vibrio spp., respectively. Our analyses revealed that the Vibrio spp. that were highly represented in the cultivable assemblage were also abundant in the culture-independent community. Epifluorescence microscopy and matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS) were utilized to detect the chemical defense molecule kahalalide F on a longitudinal section of the sacoglossan.