Almany Glenn R.

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Almany
First Name
Glenn R.
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Now showing 1 - 5 of 5
  • Preprint
    Marine dispersal scales are congruent over evolutionary and ecological time
    ( 2016-10) Pinsky, Malin L. ; Saenz-Agudelo, Pablo ; Salles, Océane C. ; Almany, Glenn R. ; Bode, Michael ; Berumen, Michael L. ; Andrefouet, Serge ; Thorrold, Simon R. ; Jones, Geoffrey P. ; Planes, Serge
    The degree to which offspring remain near their parents or disperse widely is critical for understanding population dynamics, evolution, and biogeography, and for designing conservation actions. In the ocean, most estimates suggesting short-distance dispersal are based on direct ecological observations of dispersing individuals, while indirect evolutionary estimates often suggest substantially greater homogeneity among populations. Reconciling these two approaches and their seemingly competing perspectives on dispersal has been a major challenge. However, here we show for the first time that evolutionary and ecological measures of larval dispersal can closely agree by using both to estimate the distribution of dispersal distances. In orange clownfish (Amphiprion percula) populations in Kimbe Bay, Papua New Guinea, we found that evolutionary dispersal kernels were 17 [95% CI: 12–24] km wide, while an exhaustive set of direct larval dispersal observations suggested kernel widths of 27 [19–36] km or 19 [15–27] km across two years. The similarity between these two approaches suggests that ecological and evolutionary dispersal kernels can be equivalent, and that the apparent disagreement between direct and indirect measurements can be overcome. Our results suggest that carefully applied evolutionary methods, which are often less expensive, can be broadly relevant for understanding ecological dispersal across the tree of life.
  • Preprint
    External tagging does not affect the feeding behavior of a coral reef fish, Chaetodon vagabundus (Pisces: Chaetodontidae)
    ( 2009-07-05) Berumen, Michael L. ; Almany, Glenn R.
    Increasingly, the ability to recognize individual fishes is important for studies of population dynamics, ecology, and behavior. Although a variety of methods exist, external tags remain one of the most widely applied because they are both effective and cost efficient. However, a key assumption is that neither the tagging procedure nor the presence of a tag negatively affects the individual. While this has been demonstrated for relatively coarse metrics such as growth and survival, few studies have examined the impact of tags and tagging on more subtle aspects of behavior. We tagged adult vagabond butterflyfish (Chaetodon vagabundus) occupying a 30-ha insular reef in Kimbe Bay, Papua New Guinea, using a commonly-utilized t-bar anchor tag. We quantified and compared feeding behavior (bite rate), which is sensitive to stress, of tagged and untagged individuals over four separate sampling periods spanning four months post-tagging. Bite rates did not differ between tagged and untagged individuals at each sampling period and, combined with additional anecdotal observations of normal pairing behavior and successful reproduction, suggest that tagging did not adversely affect individuals.
  • Article
    Seascape and life-history traits do not predict self-recruitment in a coral reef fish
    (The Royal Society, 2016-08-09) Herrera, Marcela ; Nanninga, Gerrit ; Planes, Serge ; Jones, Geoffrey P. ; Thorrold, Simon R. ; Saenz-Agudelo, Pablo ; Almany, Glenn R. ; Berumen, Michael L.
    The persistence and resilience of many coral reef species are dependent on rates of connectivity among sub-populations. However, despite increasing research efforts, the spatial scale of larval dispersal remains unpredictable for most marine metapopulations. Here, we assess patterns of larval dispersal in the angelfish Centropyge bicolor in Kimbe Bay, Papua New Guinea, using parentage and sibling reconstruction analyses based on 23 microsatellite DNA loci. We found that, contrary to previous findings in this system, self-recruitment (SR) was virtually absent at both the reef (0.4–0.5% at 0.15 km2) and the lagoon scale (0.6–0.8% at approx. 700 km2). While approximately 25% of the collected juveniles were identified as potential siblings, the majority of sibling pairs were sampled from separate reefs. Integrating our findings with earlier research from the same system suggests that geographical setting and life-history traits alone are not suitable predictors of SR and that high levels of localized recruitment are not universal in coral reef fishes.
  • Preprint
    First genealogy for a wild marine fish population reveals multi-generational philopatry
    ( 2016-10) Salles, Océane C. ; Pujol, Benoit ; Maynard, Jeffrey A. ; Almany, Glenn R. ; Berumen, Michael L. ; Jones, Geoffrey P. ; Saenz-Agudelo, Pablo ; Srinivasan, Maya ; Thorrold, Simon R. ; Planes, Serge
    Natal philopatry — the return of individuals to their natal area for reproduction — has advantages and disadvantages for animal populations. Natal philopatry may generate local genetic adaptation but may also increase the probability of inbreeding that can compromise persistence. While natal philopatry is well documented in anadromous fishes, marine fish may also return to their birth site to spawn. How philopatry shapes wild fish populations is, however, unclear because it requires constructing multi-generational pedigrees that are currently lacking for marine fishes. Here we present the first multi-generational pedigree for a marine fish population by repeatedly genotyping all individuals in a population of the orange clownfish (Amphiprion percula) at Kimbe Island (Papua New Guinea) over a 10-year period. Based on 2927 individuals, our pedigree analysis revealed that longitudinal philopatry was recurrent over five generations. Progeny tended to settle close to their parents, with related individuals often sharing the same colony. However, successful inbreeding was rare and genetic diversity remained high, suggesting occasional inbreeding does not impair local population persistence. Local reproductive success was dependent on the habitat larvae settled into, rather than the habitat they came from. Our study suggests that longitudinal philopatry can influence both population replenishment and local adaptation of marine fishes. Resolving multi-generational pedigrees over a relatively short time period, as we present here, provides a framework for assessing the ability of marine populations to persist and adapt to accelerating climate change.
  • Preprint
    Coral reef fish populations can persist without immigration
    ( 2015-10) Salles, Océane C. ; Maynard, Jeffrey A. ; Joannides, Marc ; Barbu, Corentin M. ; Saenz-Agudelo, Pablo ; Almany, Glenn R. ; Berumen, Michael L. ; Thorrold, Simon R. ; Jones, Geoffrey P. ; Planes, Serge
    Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parameterize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase.