title: First evidence of inbreeding, relatedness and chaotic genetic patchiness in the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa, Cnidaria).
abstract: Genetic drift and non-random mating seldom influence species with large breeding populations and high dispersal potential, characterized by unstructured gene pool and panmixia at a scale lower than the minimum dispersal range of individuals. In the present study, a set of nine microsatellite markers was developed and used to investigate the spatio-temporal genetic patterns of the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa) in the Southern Tyrrhenian Sea. Homozygote excess was detected at eight loci, and individuals exhibited intra-population relatedness higher than expected by chance in at least three samples. This result was supported by the presence of siblings in at least 5 out 8 samples, 4 of which contained full-sib in addition to half-sib dyads. Having tested and ruled out alternative explanations as null alleles, our results suggest the influence of reproductive and behavioural features in shaping the genetic structure of P. noctiluca, as outcomes of population genetics analyses pointed out. Indeed, the genetic differentiation among populations was globally small but highlighted: a) a spatial genetic patchiness uncorrelated with distance between sampling locations, and b) a significant genetic heterogeneity between samples collected in the same locations in different years. Therefore, despite its extreme dispersal potential, P. noctiluca does not maintain a single homogenous population, but rather these jellyfish appear to have intra-bloom localized recruitment and/or individual cohesiveness, whereby siblings more likely swarm together as a single group and remain close after spawning events. These findings provide the first evidence of family structures and consequent genetic patchiness in a species with highly dispersive potential throughout its whole life cycle, contributing to understanding the patterns of dispersal and connectivity in marine environments.
authors: Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Lecce, Italy; Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma, Italy.
authors: Giorgio
authors: G
authors: Aglieri
authors: Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma, Italy; Dipartimento di Biologia, Università di Padova, Padova, Italy; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.
authors: Chiara
authors: C
authors: Papetti
authors: Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma, Italy; Dipartimento di Biologia, Università di Padova, Padova, Italy.
authors: Lorenzo
authors: L
authors: Zane
authors: Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Lecce, Italy; Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma, Italy.
authors: Giacomo
authors: G
authors: Milisenda
authors: Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Lecce, Italy; Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma, Italy; Italian National Research Council - Institute for Marine Science (CNR-ISMAR), Genova, Italy.
authors: Ferdinando
authors: F
authors: Boero
authors: Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Lecce, Italy; Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma, Italy.
authors: Stefano
authors: S
authors: Piraino
mesh_terms: D000483:Alleles; D000818:Animals; D017753:Ecosystem; D019143:Evolution, Molecular; D007178:Inbreeding; D058974:Phylogeography; D011110:Polymorphism, Genetic; D037401:Scyphozoa / Q000235:genetics*