The comb jelly Mnemiopsis leidyi is considered to be a successful invasive species, partly due to its high reproduction potential. However, due to the absence of direct carbon measurements of eggs, specific reproduction rates remain uncertain. We show that egg carbon is 0.22+ 0.02 mg C and up to 21 times higher than previously extrapolated. With maximum rates of 11 232 eggs ind day, largest ani...

The relationships at the base of the metazoan tree have been difficult to robustly resolve, and there are several different hypotheses regarding the interrelationships among sponges, cnidarians, ctenophores, placozoans, and bilaterians, with each hypothesis having different implications for the body plan of the last common ancestor of animals and the paleoecology of the late Precambrian. We hav...

Medusae, siphonophores, and ctenophores are planktivorous predators operating at higher trophic levels in marine ecosystems of a wide range of productivity. It has been hypothesized that high-productivity ecosystems such as areas of upwelling tend towards food chains dominated by larger phytoplankton, large copepods, and ultimately many species of fish rather than gelatinous predators; ecosyste...

An updated checklist of medusae and ctenophores is presented for the first time for the area comprised by the Bahía Blanca Estuary, the adjacent shelf El Rincón and Monte Hermoso beach, on the southwest coast of Buenos Aires province (Argentina). The area is highly productive and provides several ecosystem services including fishing and tourism. Updated information on the biodiversity of medusa...

A sequestered germline in Metazoa has been argued to be an obstacle to lateral gene transfer (LGT), though few studies have specifically assessed this claim. Here, we test the hypothesis that the origin of a sequestered germline reduced LGT events in Bilateria (i.e., triploblast lineages) as compared to early-diverging Metazoa (i.e., Ctenophora, Cnidaria, Porifera, and Placozoa). We analyze sin...

All known visual pigments in Neuralia (Cnidaria, Ctenophora, and Bilateria) are composed of an opsin (a seven-transmembrane G protein-coupled receptor), and a light-sensitive chromophore, generally retinal. Accordingly, opsins play a key role in vision. There is no agreement on the relationships of the neuralian opsin subfamilies, and clarifying their phylogeny is key to elucidating the origin ...

Signalling through the Wnt family of secreted proteins originated in a common metazoan ancestor and greatly influenced the evolution of animal body plans. In bilaterians, Wnt signalling plays multiple fundamental roles during embryonic development and in adult tissues, notably in axial patterning, neural development and stem cell regulation. Studies in various cnidarian species have particularl...