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1.
J Fish Biol ; 103(5): 1214-1220, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37340632

ABSTRACT

Technological advances have enabled the expansion of ocean exploration to include the deep ocean, providing new species observations. Here, the authors present two new observations, captured by deep-sea cameras, of the sleeper shark Somniosus cf. pacificus from the Solomon Islands and Palau. This presents the first observation of S. cf. pacificus in the western Pacific tropics and extends its range about 2000 nautical miles south. The observations presented here provide much-needed information on the range of this species which can help guide future management and conservation actions.


Subject(s)
Dogfish , Sharks , Animals , Phylogeny , Melanesia , Pacific Ocean
2.
Evol Appl ; 16(2): 518-529, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36793699

ABSTRACT

The ability of local populations to adapt to future climate conditions is facilitated by a balance between short range dispersal allowing local buildup of adaptively beneficial alleles, and longer dispersal moving these alleles throughout the species range. Reef building corals have relatively low dispersal larvae, but most population genetic studies show differentiation only over 100s of km. Here, we report full mitochondrial genome sequences from 284 tabletop corals (Acropora hyacinthus) from 39 patch reefs in Palau, and show two signals of genetic structure across reef scales from 1 to 55 km. First, divergent mitochondrial DNA haplotypes exist in different proportions from reef to reef, causing PhiST values of 0.02 (p = 0.02). Second, closely related sequences of mitochondrial Haplogroups are more likely to be co-located on the same reefs than expected by chance alone. We also compared these sequences to prior data on 155 colonies from American Samoa. In these comparisons, many Haplogroups in Palau were disproportionately represented or absent in American Samoa, and inter-regional PhiST = 0.259. However, we saw three instances of identical mitochondrial genomes between locations. Together, these data sets suggest two features of coral dispersal revealed by occurrence patterns in highly similar mitochondrial genomes. First, the Palau-American Samoa data suggest that long distance dispersal in corals is rare, as expected, but that it is common enough to deliver identical mitochondrial genomes across the Pacific. Second, higher than expected co-occurrence of Haplogroups on the same Palau reefs suggests greater retention of coral larvae on local reefs than predicted by many current oceanographic models of larval movement. Increased attention to local scales of coral genetic structure, dispersal, and selection may help increase the accuracy of models of future adaptation of corals and of assisted migration as a reef resilience intervention.

3.
Evol Appl ; 16(2): 504-517, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36793702

ABSTRACT

The prevalence of global coral bleaching has focused much attention on the possibility of interventions to increase heat resistance. However, if high heat resistance is linked to fitness tradeoffs that may disadvantage corals in other areas, then a more holistic view of heat resilience may be beneficial. In particular, overall resilience of a species to heat stress is likely to be the product of both resistance to heat and recovery from heat stress. Here, we investigate heat resistance and recovery among individual Acropora hyacinthus colonies in Palau. We divided corals into low, moderate, and high heat resistance categories based on the number of days (4-9) needed to reach significant pigmentation loss due to experimental heat stress. Afterward, we deployed corals back onto a reef in a common garden 6-month recovery experiment that monitored chlorophyll a, mortality, and skeletal growth. Heat resistance was negatively correlated with mortality during early recovery (0-1 month) but not late recovery (4-6 months), and chlorophyll a concentration recovered in heat-stressed corals by 1-month postbleaching. However, moderate-resistance corals had significantly greater skeletal growth than high-resistance corals by 4 months of recovery. High- and low-resistance corals on average did not exhibit skeletal growth within the observed recovery period. These data suggest complex tradeoffs may exist between coral heat resistance and recovery and highlight the importance of incorporating multiple aspects of resilience into future reef management programs.

4.
PLoS One ; 17(9): e0269206, 2022.
Article in English | MEDLINE | ID: mdl-36084033

ABSTRACT

Widespread mapping of coral thermal resilience is essential for developing effective management strategies and requires replicable and rapid multi-location assays of heat resistance and recovery. One- or two-day short-term heat stress experiments have been previously employed to assess heat resistance, followed by single assays of bleaching condition. We tested the reliability of short-term heat stress resistance, and linked resistance and recovery assays, by monitoring the phenotypic response of fragments from 101 Acropora hyacinthus colonies located in Palau (Micronesia) to short-term heat stress. Following short-term heat stress, bleaching and mortality were recorded after 16 hours, daily for seven days, and after one and two months of recovery. To follow corals over time, we utilized a qualitative, non-destructive visual bleaching score metric that correlated with standard symbiont retention assays. The bleaching state of coral fragments 16 hours post-heat stress was highly indicative of their state over the next 7 days, suggesting that symbiont population sizes within corals may quickly stabilize post-heat stress. Bleaching 16 hours post-heat stress predicted likelihood of mortality over the subsequent 3-5 days, after which there was little additional mortality. Together, bleaching and mortality suggested that rapid assays of the phenotypic response following short-term heat stress were good metrics of the total heat treatment effect. Additionally, our data confirm geographic patterns of intraspecific variation in Palau and show that bleaching severity among colonies was highly correlated with mortality over the first week post-stress. We found high survival (98%) and visible recovery (100%) two months after heat stress among coral fragments that survived the first week post-stress. These findings help simplify rapid, widespread surveys of heat sensitivity in Acropora hyacinthus by showing that standardized short-term experiments can be confidently assayed after 16 hours, and that bleaching sensitivity may be linked to subsequent survival using experimental assessments.


Subject(s)
Anthozoa , Hyacinthus , Animals , Anthozoa/physiology , Coral Reefs , Heat-Shock Response , Reproducibility of Results , Symbiosis
5.
Elife ; 102021 08 13.
Article in English | MEDLINE | ID: mdl-34387190

ABSTRACT

Climate change is dramatically changing ecosystem composition and productivity, leading scientists to consider the best approaches to map natural resistance and foster ecosystem resilience in the face of these changes. Here, we present results from a large-scale experimental assessment of coral bleaching resistance, a critical trait for coral population persistence as oceans warm, in 221 colonies of the coral Acropora hyacinthus across 37 reefs in Palau. We find that bleaching-resistant individuals inhabit most reefs but are found more often in warmer microhabitats. Our survey also found wide variation in symbiont concentration among colonies, and that colonies with lower symbiont load tended to be more bleaching-resistant. By contrast, our data show that low symbiont load comes at the cost of lower growth rate, a tradeoff that may operate widely among corals across environments. Corals with high bleaching resistance have been suggested as a source for habitat restoration or selective breeding in order to increase coral reef resilience to climate change. Our maps show where these resistant corals can be found, but the existence of tradeoffs with heat resistance may suggest caution in unilateral use of this one trait in restoration.


Subject(s)
Anthozoa/growth & development , Anthozoa/parasitology , Coral Reefs , Genetic Variation , Global Warming , Symbiosis , Thermotolerance , Animals , Anthozoa/genetics , Chlorophyll/analysis , Conservation of Natural Resources , Palau , Symbiosis/genetics , Thermotolerance/genetics
6.
Proc Biol Sci ; 286(1897): 20182908, 2019 02 27.
Article in English | MEDLINE | ID: mdl-30963834

ABSTRACT

Understanding processes that drive community recovery are needed to predict ecosystem trajectories and manage for impacts under increasing global threats. Yet, the quantification of community recovery in coral reefs has been challenging owing to a paucity of long-term ecological data and high frequency of disturbances. Here we investigate community re-assembly and the bio-physical drivers that determine the capacity of coral reefs to recover following the 1998 bleaching event, using long-term monitoring data across four habitats in Palau. Our study documents that the time needed for coral reefs to recover from bleaching disturbance to coral-dominated state in disturbance-free regimes is at least 9-12 years. Importantly, we show that reefs in two habitats achieve relative stability to a climax community state within that time frame. We then investigated the direct and indirect effects of drivers on the rate of recovery of four dominant coral groups using a structural equation modelling approach. While the rates of recovery differed among coral groups, we found that larval connectivity and juvenile coral density were prominent drivers of recovery for fast growing Acropora but not for the other three groups. Competitive algae and parrotfish had negative and positive effects on coral recovery in general, whereas wave exposure had variable effects related to coral morphology. Overall, the time needed for community re-assembly is habitat specific and drivers of recovery are taxa specific, considerations that require incorporation into planning for ecosystem management under climate change.


Subject(s)
Anthozoa/physiology , Biodiversity , Climate Change , Coral Reefs , Animals , Anthozoa/growth & development , Larva/growth & development , Larva/physiology , Palau
7.
Lima; s.n; 2015. 58 p. tab.
Thesis in Spanish | LIPECS | ID: biblio-1113906

ABSTRACT

Con la finalidad de determinar los factores de riesgo de anemia en pacientes adultos mayores hospitalizados en los Servicios de Medicina del Hospital Arzobispo Loayza, se realizó un estudio explicativo, longitudinal, retrospectivo y prolectivo en una muestra representativa de 150 pacientes de la tercera edad 75 con anemia y 75 sin ella. Se encontraron como resultados que los factores de riesgo de anemia por enfermedad crónica en pacientes adultos mayores encontrados fueron la disfunción renal y el cáncer diagnosticado, por deficiencia de hierro fueron la presencia de angiodisplasia, cáncer y pólipos. Otros factores de riesgo de anemia estuvieron asociados al consumo reducido de Vit B12, la absorción intestinal reducida, la anorexia, y los trastornos del tránsito intestinal. La deficiencia de ácido fólico en la ingestión dietética inadecuada y la desnutrición también constituyeron factores de riesgo. El factor de riesgo de anemia por Síndromes mielodisplásicos en pacientes adultos mayores fue la presencia de hemorragias. Finalmente los factores demográficos como sexo y edad fueron dimensiones de riesgo de anemia en pacientes adultos mayores.


In order to determine the risk factors of anemia in elderly patients hospitalized in the medical Hospital Arzobispo Loayza, a descriptive, longitudinal, retrospective, and prolective study was conducted in a representative sample of 150 elderly patients 75 with anemia and 75 without. Results were found as risk factors of anemia of chronic disease in the elderly patients were found renal dysfunction and cancer diagnosed iron deficiency were the presence of angiodysplasy, cancer and polyps. Other risk factors for anemia were associated with reduced consumption of VB 12, reduced intestinal absorption, anorexia, and intestinal transit disorders. Deficiency of folic acid in inadequate dietary intake and malnutrition also were risk factors. The risk factor of anemia in myelodysplastic syndromes in elderly patients was the presence of bleeding and no drugs were reported to be risk factors for anemia. Finally, demographic factors such as gender and age were risk dimensions of anemia in elderly patients.


Subject(s)
Male , Female , Humans , Middle Aged , Aged , Aged, 80 and over , Anemia , Risk Factors , Hospitalization , Longitudinal Studies , Retrospective Studies , Case-Control Studies
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