38 research outputs found
Development and growth of hatchery-reared larval Florida pompano (Trachinotus carolinus)
Although the Florida pompano (Trachinotus carolinus) is
a prime candidate for aquaculture, the problematic production of juveniles remains a major impediment to
commercial culture of this species. In order to improve the understanding of larval development and to refine hatchery production techniques, this study was conducted to characterize development and growth of Florida pompano from hatching through metamorphosis by using digital photography
and image analysis. Newly hatched larvae were transparent and had a large, elongate yolk sac and single oil globule. The lower and upper jaws as well as the digestive tract
were not fully developed at hatching. Rotifers were observed in the stomach of larvae at three days after hatching (DAH), and Artemia spp. were observed in the stomach of larvae at 14 DAH. Growth rates calculated
from total length measurements were 0.22 ±0.04, 0.23 ±0.12, and 0.35 ±0.09 mm/d for each of the larval rearing trials. The mouth gape of larvae was 0.266 ±0.075 mm at first feeding and increased with a growth rate of 0.13 ± 0.04 mm/d. Predicted values for optimal prey sizes ranged from 80
to 130 μm at 3 DAH, 160 to 267 μm at 5 DAH, and 454 to 757 μm at 10 DAH. Based on the findings of this study, a refined feeding regime was developed to provide stage- and size-specific guidelines for feeding Florida pompano larvae reared under hatchery co
Bioenergetics and Trophic Impacts of Invasive Indo-Pacific Lionfish
Indo-Pacific lionfish, Pterois volitans and Pterois miles, are non-native marine fish with established populations in the western North Atlantic Ocean and Caribbean Sea. Rapid population growth threatens native fish communities and they are considered invasive species. A bioenergetics model was developed for lionfish and applied to populations inhabiting the western North Atlantic Ocean to model the potential impact of these predators on native reef ecosystems. Model parameters were derived by laboratory evaluation of consumption and respiration rates from 14 to 32° C and fish size ranging from 19 to 400 g. The model was calibrated with laboratory growth and consumption data, and model performance was analyzed to evaluate the parameters most sensitive to error. The optimal temperature for lionfish consumption is 29.8° C. Energy allocated to gamete production reduces female lionfish growth rate compared to males and limits maximum body size. Based on the environmental conditions and observed growth, daily consumption estimates of 393 lionfish [dot in center of line] ha-1 could remove up to 2.186 kg prey [dot in center of line] d-1 during the summer in the Bahamas. The corroborated model is a useful tool for examining the influence of temperature on predation rates, and exploring the interaction between lionfish and prey.  M.S
The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats
The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well
Bioenergetics and Trophic Impacts of Invasive Indo-Pacific Lionfish
Indo-Pacific lionfish Pterois volitans and Pterois miles are non-native marine fish with established populations in the western North Atlantic Ocean and Caribbean Sea. Rapid population growth threatens native fish communities and they are considered invasive species. A bioenergetics model was developed for lionfish and applied to populations inhabiting the western North Atlantic Ocean to model the potential impact of these predators on native reef ecosystems. Model parameters were derived by laboratory evaluation of consumption and respiration rates from 14 to 32° C and fish size ranging from 19 to 400 g. The model was calibrated with laboratory growth and consumption data and model performance was analyzed to evaluate the parameters most sensitive to error. The optimal temperature for lionfish consumption is 29.8° C. Energy allocated to gamete production reduces female lionfish growth rate compared to males and limits maximum body size. Based on the environmental conditions and observed growth daily consumption estimates of 393 lionfish [dot in center of line] ha-1 could remove up to 2.186 kg prey [dot in center of line] d-1 during the summer in the Bahamas. The corroborated model is a useful tool for examining the influence of temperature on predation rates and exploring the interaction between lionfish and prey.
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Longitudinal change in daily stress across 20 years of adulthood: Results from the national study of daily experiences.
This study examined age-related patterns in exposure and affective reactivity to daily stressors across a 20-year time span among adults who were between 22 and 77 years old at their baseline interview. Longitudinal data from the National Study of Daily Experiences (NSDE) consisted of three bursts of eight consecutive nightly interviews of stress and affect. Analyses made use of all available data from a U.S. National sample of respondents who participated in any of the three NSDE bursts (N = 2,845; number of daily assessments = 33,688). Findings revealed increasing age-related benefits. Younger adults (< 30 years) reported the highest levels of stressor exposure and reactivity, but their stress profile improved with age. Over time, adults averaged an 11% reduction in the occurrence of stressor days, and the younger adults exhibited an even steeper decline (a 47% reduction) in their levels of stressor reactivity. For people in midlife and old age, stressor occurrence continued to decrease over time, yet among adults aged 54 years or older at baseline, stress reactivity remained stable across time. (PsycInfo Database Record (c) 2023 APA, all rights reserved)
Comparing targeted exome and whole exome approaches for genetic diagnosis of neuromuscular disorders
Massively parallel sequencing is rapidly becoming a widely used method in genetic diagnostics. However, there is still no clear consensus as to which approach can most efficiently identify the pathogenic mutations carried by a given patient, while avoiding false negative and false positive results. We developed a targeted exome approach (MyoPanel2) in order to optimize genetic diagnosis of neuromuscular disorders. Using this approach, we were able to analyse 306 genes known to be mutated in myopathies as well as in related disorders, obtaining 98.8% target sequence coverage at 20×. Moreover, MyoPanel2 was able to detect 99.7% of 11,467 known mutations responsible for neuromuscular disorders. We have then used several quality control parameters to compare performance of the targeted exome approach with that of whole exome sequencing. The results of this pilot study of 140 DNA samples suggest that targeted exome sequencing approach is an efficient genetic diagnostic test for most neuromuscular diseases
Reproduction, larviculture and early development of the Bluebanded goby, Lythrypnus dalli, an emerging model organism for studies in evolutionary developmental biology and sexual plasticity
The Bluebanded goby, Lythrypnus dalli, is a popular ornamental aquarium species and a key organism for the study of several fundamental biological questions, most notably reversible sex change in adults. To maximize the tractability of this species as an emerging model system, it is essential to have an optimized propagation system and a detailed developmental staging scheme. One limitation to the larviculture of L. dalli is the relatively small size of the larvae, which makes the transition from yolk to feeding challenging. We developed a protocol and successfully reared three generations of L. dalli in the laboratory. The protocol contains several key innovations for the rearing of diminutive fish larvae, including tank design and co-culturing of microalgae (Isochrysis galbana) with copepods (Parvocalanus sp.) in the larval rearing tanks. In addition, we describe the embryonic and larval development of L. dalli under controlled conditions and in comparison with the model organism Danio rerio. We found that at 21°C L. dalli larvae hatch in 4 days, reach flexion in 18-25 days and are sexually mature by 3 months. Overall, the embryonic development of L. dalli is remarkably similar to D. rerio with several striking differences, including the position and shape of the blastomere, size of the neuromasts and corresponding cupula, and relative timing of pigmentation and brain subdivision. The ability to rear this species in captivity is a valuable tool that could be utilized for a variety of similarly diminutive species and to address a greater breadth and depth of biological questions
Ecological time series and integrative taxonomy unveil seasonality and diversity of the toxic diatom Pseudo-nitzschia H. Peragallo in the northern Adriatic Sea
MONITORAGGIO GEOCHIMICO-AMBIENTALE DEI SUOLI DELLA REGIONE CAMPANIA. PROGETTO CAMPANIA TRASPARENTE. VOLUME 3
Il volume illustra i risultati del monitoraggio geochimico-ambientale finalizzato alla valutazione dell’inquinamento da Contaminanti Organici Persistenti (noti nella letteratura come POP - Persistent Organic Pollutants) e Elementi Potenzialmente Tossici (EPT) della matrice aria della Regione Campania. Tale lavoro è stato svolto nell’ambito del “Programma Campania Trasparente - Attività di Monitoraggio Integrato per la Regione Campania”. Progetto finanziato dalla Regione Campania, attraverso l’IZSM, nell’ambito del Del.G.R. n. 497/2013: Fondo per le Misure Anticicliche e la Salvaguardia dell’Occupazione - Azione B4 “Mappatura del Territorio” approvato con il Decreto Esecutivo DG “Sviluppo Economico” n. 585, 14/09/2015. Le mappe prodotte rivestono particolare importanza in quanto mostrano la distribuzione nell’aria delle concentrazioni dei vari composti ed elementi analizzati (IPA, PCB, OCP, PBDE e EPT). Negli ultimi anni, la Campania è stata oggetto di attenzione mediatica per il presunto degrado dei territori agricoli di un’area tristemente nota come “Terra dei Fuochi”. La mancanza di una copertura di dati geochimici ad alta densità spaziale attestanti la presenza effettiva di contaminanti nelle diverse matrici ambientali dell’area ha favorito l’insorgere e la diffusione di allarmi relativi ad emergenze ambientali non meglio definite in termini di estensione territoriale ed impatto sanitario. Le indagini effettuate, con il Progetto Campania Trasparente, sono servite ad implementare la conoscenza geochimica esaustiva dell’intero territorio regionale- che rende la Campania la Regione meglio monitorata in Italia dal punto di vista ambientale. L’auspicio è che il monitoraggio (e la relativa cartografia) prodotto in Campania venga preso a modello dalle altre Regioni italiane, in modo da coprire l’intero territorio nazionale