Papers by Giacomo Bernardi
Journal of Molecular Evolution, Nov 30, 1986
Journal of Molecular Evolution
Journal of Molecular Evolution
Despite more than a century of coral reef research, the basic biology of reef corals remained poo... more Despite more than a century of coral reef research, the basic biology of reef corals remained poorly understood until the advent of scuba diving and the associated underwater technol-ogy that followed. Basic information such as the nature of the coral–algal symbiosis, the importance of coral heterotrophy, specialized structures for space competition, the role of mutualistic crustacean symbionts, the behavior and dispersal ability of coral larvae, the nature of coral protection from ultraviolet radiation and heat stress, and the effects of ocean currents and internal waves on reefs all beneted from the ability of scientists to spend time under water observing, making measurements, and carrying out experiments. In addition to enhancing our understanding of corals themselves, the ability to spend time under water has also provided a huge amount of information about coral reef ecosystems and their component species. These benets were further enhanced by new opportunities for saturation ...
Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet thei... more Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet their evolutionary history remains enigmatic. We employed next generation sequencing of mitogenomes for nine of the 11 recognized species and two outgroups; as well as additional Sanger sequencing of two mitochondrial and two nuclear genes in an extended taxon sampling set. Analysis of the mitogenome coding regions in a Maximum Likelihood and Bayesian framework provided a well-resolved phylogeny. The deepest divergences distinguished three clades with high support, one containing Manta birostris, Manta alfredi, Mobula tarapacana, Mobula japanica and Mobula mobular; one containing Mobula kuhlii, Mobula eregoodootenkee and Mobula thurstoni; and one containing Mobula munkiana, Mobula hypostoma and Mobula rochebrunei. Mobula remains paraphyletic with the inclusion of Manta, a result that is in agreement with previous studies based on molecular and morphological data. A fossil-calibrated Bayesian random local clock analysis suggests that mobulids diverged from Rhinoptera around 30 Mya. Subsequent divergences are characterized by long internodes followed by short bursts of speciation extending from an initial episode of divergence in the Early and Middle Miocene (19-17 Mya) to a second episode during the Pliocene and Pleistocene (3.6 Mya -recent). Estimates of divergence dates overlap significantly with periods of global warming, during which upwelling intensity -and related high primary productivity in upwelling regions -decreased markedly. These periods are hypothesized to have led to fragmentation and isolation of feeding regions leading to possible regional extinctions, as well as the promotion of allopatric speciation. The closely shared evolutionary history of mobulids in combination with ongoing threats from fisheries and climate change effects on upwelling and food supply, reinforces the case for greater protection of this charismatic family of pelagic filter feeders.
Journal of molecular evolution, 1999
Molecular phylogenetics and evolution, 1999
Labroid fishes include a variety of families, such as wrasses (Labridae), odacids (Odacidae), dam... more Labroid fishes include a variety of families, such as wrasses (Labridae), odacids (Odacidae), damselfishes (Pomacentridae), parrotfishes (Scaridae), cichlids (Cichlidae), and surfperches (Embiotocidae). With only 23 species, the small embiotocid family exhibits a remarkably low species diversity compared to the large species diversity of the Cichlidae. Using mitochondrial DNA sequences of all 14 extant embiotocid genera, we established a molecular phylogeny of the family and compared it with a previously proposed morphological phylogeny. Genetic differentiation among embiotocids was compared to that among cichlids. Although species numbers are extremely different between these two families, the degrees of genetic differentiation within each family was found to be very similar.
Biological Invasions, 2014
We investigate the genetic diversity of the sweeper Pempheris, a biological invader that entered ... more We investigate the genetic diversity of the sweeper Pempheris, a biological invader that entered the Mediterranean Sea via the Suez Canal. Two mitochondrial regions and one nuclear region were sequenced and topological reconstructions investigated from samples collected from the eastern Mediterranean Sea, Red Sea and three Indo-Pacific localities. Morphological and molecular analyses assigned samples from this study to three distinct species of Pempheris in the Red Sea (P. flavicyla, P. rhomboidea, and P. tominagai) and confirmed a misidentification of the Mediterranean sweepers, previously identified as P. vanicolensis and now recognized as P. rhomboidea. Pempheris rhomboidea clustered in a single clade including specimens from Madagascar and South Africa. Similarly to most other studied Lessepsian bioinvaders, no evidence of a genetic bottleneck in its invasive Mediterranean population was found. Yet, lowered gene flow levels were observed between Red Sea and Mediterranean populations in this species. These findings highlight the importance of molecular tools to the proper identification of morphologically challenging alien organisms and contribute to the understanding of the dynamics of Lessepsian invasions.
Marine Ecology, 2015
Biological invasions result in huge ecological and economic impacts; therefore, a great amount of... more Biological invasions result in huge ecological and economic impacts; therefore, a great amount of effort is dedicated to predicting the potential success of newly established or candidate bioinvaders. Thus far, over 90 species of fish have entered the Mediterranean Sea via the Suez canal, the so-called Lessepsian bioinvaders. The bluespotted cornetfish, Fistularia commersonii, is remarkable in its ability to disperse within the Mediterranean and has been dubbed 'the Lessepsian sprinter'. In just a few years, starting in 2000, it expanded over the entire area, from the Suez Canal to Gibraltar. Theoretical predictions correlate the dispersal capabilities of an invader in its native range (using the population genetic metrics, F st , as a proxy) with its dispersal capability in its invading area (continuous extent of spread, CES). Here, we estimated the population genetic characteristics of Indo-Pacific native populations of F. commersonii in order to determine if this Lessepsian 'sprinter' fits the predictive model of dispersal. Indeed, we found that even in the case of such a very rapid range expansion, the predicted relationship between F st and CES is fulfilled in F. commersonii.
Numerous studies have demonstrated population genetic structuring in marine species, yet few have... more Numerous studies have demonstrated population genetic structuring in marine species, yet few have investigated the effect of vertical zonation on gene flow and population structure. Here we use three sympatric, closely related clinid species, Clinus cottoides, C. superciliosus and Muraenoclinus dorsalis, to test whether zonation on South African intertidal rocky shores affects phylogeographic patterns. We show that the high-shore restricted species has reduced gene flow and considerably higher F ST values (F ST = 0.9) than the mid-and low-shore species (F ST < 0.14). Additionally, we provide evidence for remarkably different demographic and evolutionary histories, ranging from extreme population bottlenecks to population persistence, which are probably linked to effective population size and habitat specialisation. This study further highlights the need for a multispecies approach to unravel the biological and evolutionary processes that drive extant population genetic patterns in marine species, as even closely related species with similar life histories show highly variable results.
Your article is protected by copyright and all rights are held exclusively by Springer Science +B... more Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media Dordrecht. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Molecular Phylogenetics and Evolution, 2015
Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet thei... more Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet their evolutionary history remains enigmatic. We employed next generation sequencing of mitogenomes for nine of the 11 recognized species and two outgroups; as well as additional Sanger sequencing of two mitochondrial and two nuclear genes in an extended taxon sampling set. Analysis of the mitogenome coding regions in a Maximum Likelihood and Bayesian framework provided a well-resolved phylogeny. The deepest divergences distinguished three clades with high support, one containing Manta birostris, Manta alfredi, Mobula tarapacana, Mobula japanica and Mobula mobular; one containing Mobula kuhlii, Mobula eregoodootenkee and Mobula thurstoni; and one containing Mobula munkiana, Mobula hypostoma and Mobula rochebrunei. Mobula remains paraphyletic with the inclusion of Manta, a result that is in agreement with previous studies based on molecular and morphological data. A fossil-calibrated Bayesian random local clock analysis suggests that mobulids diverged from Rhinoptera around 30 Mya. Subsequent divergences are characterized by long internodes followed by short bursts of speciation extending from an initial episode of divergence in the Early and Middle Miocene (19-17 Mya) to a second episode during the Pliocene and Pleistocene (3.6 Mya -recent). Estimates of divergence dates overlap significantly with periods of global warming, during which upwelling intensity -and related high primary productivity in upwelling regions -decreased markedly. These periods are hypothesized to have led to fragmentation and isolation of feeding regions leading to possible regional extinctions, as well as the promotion of allopatric speciation. The closely shared evolutionary history of mobulids in combination with ongoing threats from fisheries and climate change effects on upwelling and food supply, reinforces the case for greater protection of this charismatic family of pelagic filter feeders.
PLoS ONE, 2012
Reef fishes exhibit a bipartite life cycle where a benthic adult stage is preceded by a pelagic d... more Reef fishes exhibit a bipartite life cycle where a benthic adult stage is preceded by a pelagic dispersal phase during which larvae are presumed to be mixed and transported by oceanic currents. Genetic analyses based on twelve microsatellite loci of 181 three-spot dascyllus (Dascyllus trimaculatus) that settled concurrently on a small reef in French Polynesia revealed 11 groups of siblings (1 full sibs and 10 half-sibs). This is the first evidence that fish siblings can journey together throughout their entire planktonic dispersal phase (nearly a month long for three-spot dascyllus). Our findings have critical implications for the dynamics and genetic structure of fish populations, as well as for the design of marine protected areas and management of fisheries.
Oecologia, 2014
found that, by removing large amounts of physical habitat, a tropical cyclone had larger impacts ... more found that, by removing large amounts of physical habitat, a tropical cyclone had larger impacts on reef fish communities than an outbreak of coral-eating sea stars that caused widespread coral mortality but left the physical structure intact. In addition, the impacts of declining structural complexity on reef fish assemblages accelerated as structure became increasingly rare. structure provided by dead coral colonies can take up to decades to erode following coral mortality, and, consequently, our results suggest that predictions based on short-term studies are likely to grossly underestimate the long-term impacts of coral decline on reef fish communities.
Molecular systematics of fishes, 1997
... ago. Acknowledgments This study would not have been possible without the samples or sequences... more ... ago. Acknowledgments This study would not have been possible without the samples or sequences provided by Chris Grant, BG Granier, Chris Stowell, Rodney Harper, Shane Anderson, Albert Stock, and David Stock. Chris ...
The Quarterly Review of Biology, 1994
The Quarterly Review of Biology, 2003
Reviews in Fish Biology and Fisheries, 2011
The population morphometric variation of the endangered freshwater killifish (Fundulus lima) was ... more The population morphometric variation of the endangered freshwater killifish (Fundulus lima) was evaluated and compared with that of its euryhaline coastal relatives (
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Papers by Giacomo Bernardi