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The swimming larvae of many marine animals identify a location on the seafloor to settle and undergo metamorphosis based on the presence of specific surface-bound bacteria. While bacteria-stimulated metamorphosis underpins processes such as the fouling of ship hulls, animal development in aquaculture, and the recruitment of new animals to coral reef ecosystems, little is known about the mechanisms governing this microbe-animal interaction. Here we review what is known and what we hope to learn about how bacteria and the factors they produce stimulate animal metamorphosis. With a few emerging model systems, including the tubeworm Hydroides elegans, corals, and the hydrozoan Hydractinia, we have begun to identify bacterial cues that stimulate animal metamorphosis and test hypotheses addressing their mechanisms of action. By understanding the mechanisms by which bacteria promote animal metamorphosis, we begin to illustrate how, and explore why, the developmental decision of metamorphosis relies on cues from environmental bacteria.

Cáhuil Lagoon in central Chile harbors distinct microbial communities in various solar salterns that are arranged as interconnected ponds with increasing salt concentrations. Here, we report the metagenome of the 3.0- to 0.2-µm fraction of the microbial community present in a crystallizer pond with 34% salinity.

Species of Microcystis are the most common bloom‐forming cyanobacteria in several countries. Despite extensive studies regarding the production of bioactive cyanopeptides in this genus, there are limited data on isolated strains from Brazil. Three Microcystis sp. strains were isolated from the Salto Grande Reservoir (LTPNA01, 08 and 09) and investigated for the presence of mcy genes, microcystins and other cyanopeptides. Microcystin and microginin production was confirmed in two isolates using high‐resolution tandem mass spectrometry after electrospray ionization (ESI‐Q‐TOF), and the structures of two new microginin congeners were proposed (MG756 Ahda‐Val‐Leu‐Hty‐Tyr and MG770 MeAhda‐Val‐Leu‐Hty‐Tyr). The biosynthesis profile of the identified cyanopeptides was evaluated at different growth phases via a newly developed HPLC‐UV method. Results demonstrated no substantial differences in the production of microcystins and microginins after data normalization to cell quota, suggesting a constitutive biosynthesis. This study represents the first confirmed co‐production of microginins and microcystins in Brazilian strains of Microcystis sp. and highlights the potential of Brazilian cyanobacteria as a source of natural compounds with pharmaceutical interest.

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