Center. In our study, we used microsatellite genotypes to infer that 57 of 491 new splitnose rockfish (Sebastes diploproa) recruits were siblings, suggesting cohesive dispersal over a 4-6 month period. After their examination of the raw data, Drs. Anderson and Garza suggested an alternative hypothesis in which the results derived from the existence of a cryptic species within our sample collection. We supplied them with all of the biological samples to reanalyze using a novel next-generation sequencing approach for species identification. The results from the new approach were confirmed by sequencing the control region of the mitochondrial genome. Together these new analyses reveal that instead of groups of siblings and nonsiblings, our juvenile samples consisted of two different rockfish species: splitnose rockfish and redbanded rockfish (S. babcocki). Given these new findings, we conclude that our estimates of relatedness were inflated within dyads containing individuals from the same species. Thus, while it is still possible that siblings may travel together in the pelagic ocean, we currently do not have evidence to support this hypothesis. The application of increasingly advanced molecular techniques to address fundamental ecological questions is of immense benefit to the field of marine ecology. As genetic techniques continue to rapidly evolve, we are firm supporters of open science and the publishing of raw data that allows vetting and collegial collaboration to advance science. We hereby retract the article and regret any inconvenience that it may have caused."Published under the PNAS license.www.pnas.org/cgi

Pelagia noctiluca is the most successful and well-studied jellyfish in the Mediterranean Sea. This species tolerates a wide range of water temperatures and succeeds in low to medium food regimes, but factors driving its distribution and population dynamics remain poorly understood. Here we applied a multiscale analytical approach using survey data and a physical-biochemical coupled model to assess how environmental factors affect the 3-dimensional distribution and seasonal abundance of P. noctiluca early life stages. The surveys took place after the spring bloom, when warm water favors fecundity and growth, but food shortage limits the reproductive investment and early survival. We found that most early life stages of P. noctiluca remained above the shallow thermocline and upper mixed layer where temperature is warm. Their spatial distribution was positively correlated with surface chlorophyll concentration, and over 90% of the variation in interannual abundance was explained by basin-scale productivity in June. Warmer water during winter and spring seasons coupled with protracted spring blooms increase the population of P. noctiluca, and this explains the trend of increasing outbreaks observed in the western Mediterranean Sea over the past decades.

Bluefin tunas across the world migrate long distances to spawn in particularly warm and oligotrophic areas constrained by oceanographic fronts. The low abundance of predators in these areas increases survival chances of their early life stages, but its importance for choice of spawning habitat is unknown. Here, we use estimated clearance rates and data on spatial distributions of Atlantic bluefin tuna larvae Thunnus thynnus and metaephyrae of the jellyfish Pelagia noctiluca to quantify predation at a major spawning ground in the Mediterranean Sea. We found that high densities of P. noctiluca can rapidly deplete tuna eggs and preflexion larvae, but their patchy distribution and low spatial and temporal overlap results in overall low predation. The specific distribution of the spawning sites suggests that bluefin tunas may use local oceanography as cues to spawn outside areas with high predator densities.

No abstract

Most marine fishes die during their first days of life falling prey for other animals, and even minor changes in early predation rates can lead to order-of-magnitude variation in the number of individuals recruiting to the adult population. However, quantifying predation in fish early life stages and linking species-specific interactions to recruitment and population dynamics is challenging. Here, we test the hypothesis that recovery of the commercially exploited Atlantic bluefin tuna can affect early survival of the Mediterranean albacore through predator-prey interactions of their early life stages. We find that when the predator species is present, they have a large predatory capacity on the prey species, but their patchy distribution may limit their total effect. Along with other processes affecting early survival, this interaction can contribute to a loss of recruitment potential to later stages.