Measurement of swimming ability in larval marine fishes: comparison of critical speed with in situ speed

2020 ◽  
Vol 650 ◽  
pp. 203-215 ◽  
Author(s):  
JM Leis
Keyword(s):  
Larval Dispersal ◽  
Critical Speed ◽  
Fish Larvae ◽  
Marine Fishes ◽  
Genetic Connectivity ◽  
Swimming Ability ◽  
Strongly Correlated ◽  
Laboratory Measure ◽  
Laboratory Flume

For much of their pelagic larval dispersal (PLD) stage, larval perciform fishes are able to directly influence their dispersal by horizontal swimming, but it is unclear which means of measuring swimming ability is most appropriate for modelling dispersal and studying demographic and genetic connectivity. Most studies use critical speed (Ucrit), a laboratory flume measure derived by increasing flow until larvae can no longer maintain their position. Most swimming ability data on fish larvae are Ucrit, usually for larvae nearing the end of PLD. Recognizing that a forced laboratory measure is inappropriate for dispersal, researchers have used decreased Ucrit values, usually by 50%, and have argued that Ucrit is strongly correlated with more relevant swimming measures. Here I examined the suitability of Ucrit versus in situ speed (ISS), wherein speed of larvae is measured by divers following them in the ocean with a flow meter. Considerations of dispersal require inclusion of swimming ontogeny. Swimming speed regressions of speed on size of 10 species in 8 families showed that Ucrit and ISS are not well correlated. The Ucrit:standard length (SL) slope was greater than the ISS:SL slope in 6 species, and did not differ in the other 4 species. No overall metric, e.g. X% of Ucrit = ISS, was appropriate for conversion of Ucrit to ISS. Conversion of Ucrit to ISS is not straightforward. Ucrit measures swimming potential, not what larvae do in the ocean, whereas ISS directly measures larvae swimming in the ocean. Ucrit ontogeny is less variable, but ISS ontogeny is more relevant to dispersal. Ucrit may be useful for other purposes.

scholarly journals Exploration of the “larval pool”: development and ground-truthing of a larval transport model off leeward Hawai‘i

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1636 ◽  
Author(s):  
Johanna L.K. Wren ◽  
Donald R. Kobayashi
Keyword(s):  
Reef Fish ◽  
Larval Dispersal ◽  
Transport Model ◽  
Fish Larvae ◽  
Additive Model ◽  
Larval Transport ◽  
Distribution Model ◽  
Lunar Phase ◽  
Fish Distributions

Most adult reef fish show site fidelity thus dispersal is limited to the mobile larval stage of the fish, and effective management of such species requires an understanding of the patterns of larval dispersal. In this study, we assess larval reef fish distributions in the waters west of the Big Island of Hawai‘i using bothin situand model data. Catches from Cobb midwater trawls off west Hawai‘i show that reef fish larvae are most numerous in offshore waters deeper than 3,000 m and consist largely of pre-settlement Pomacanthids, Acanthurids and Chaetodontids. Utilizing a Lagrangian larval dispersal model, we were able to replicate the observed shore fish distributions from the trawl data and we identified the 100 m depth strata as the most likely depth of occupancy. Additionally, our model showed that for larval shore fish with a pelagic larval duration longer than 40 days there was no significant change in settlement success in our model. By creating a general additive model (GAM) incorporating lunar phase and angle we were able to explain 67.5% of the variance between modeled andin situAcanthurid abundances. We took steps towards creating a predictive larval distribution model that will greatly aid in understanding the spatiotemporal nature of the larval pool in west Hawai‘i, and the dispersal of larvae throughout the Hawaiian archipelago.

scholarly journals First evidence of fish larvae producing sounds

2014 ◽  
Vol 10 (10) ◽  
pp. 20140643 ◽  
Author(s):  
Erica Staaterman ◽  
Claire B. Paris ◽  
Andrew S. Kough
Keyword(s):  
Visual Cues ◽  
Sound Production ◽  
Fish Larvae ◽  
Early Life History ◽  
Marine Fishes ◽  
Physiological Mechanisms ◽  
Life History Stages ◽  
Lutjanus Griseus ◽  
Exact Function

The acoustic ecology of marine fishes has traditionally focused on adults, while overlooking the early life-history stages. Here, we document the first acoustic recordings of pre-settlement stage grey snapper larvae ( Lutjanus griseus ). Through a combination of in situ and unprovoked laboratory recordings, we found that L. griseus larvae are acoustically active during the night, producing ‘knock’ and ‘growl’ sounds that are spectrally and temporally similar to those of adults. While the exact function and physiological mechanisms of sound production in fish larvae are unknown, we suggest that these sounds may enable snapper larvae to maintain group cohesion at night when visual cues are reduced.

scholarly journals Preliminary Study on Fish Larvae at Selected Coastal Waters of Sarawak

1970 ◽  
Vol 4 (2) ◽  
pp. 1-8
Author(s):  
Norhakimi Muhamad ◽  
Siti Akmar Khadijah Ab Rahim
Keyword(s):  
Coastal Waters ◽  
Intertidal Zone ◽  
Larval Dispersal ◽  
Sampling Methods ◽  
Fish Larvae ◽  
Mesh Size ◽  
Subtidal Zone ◽  
Preliminary Study ◽  
Study Sites

A survey were carried out from April to November 2012 at five study sites namely Teluk Pandan beach, Rambungan beach, Puteri beach, Sampadi Island and Satang Besar Island, Sarawak. This survey was carried out in order to obtain early documentation of fish larvae at selected coastal waters of Sarawak. Seine net (1 mm mesh size) which was pulled by two persons at intertidal zone; and bridle net (0.5 mm mesh size) that was towed by boat at subtidal zone (Sampadi Island only) were used to collect the samples. A total of 2,562 fish larvae which comprise 25 families were obtained from both sampling methods. A total of 16 families of fish larvae were caught by seine net from the intertidal zone. The same number of families was collected at the subtidal zone of Sampadi Island by bridle net. Ambassidae, Clupeidae, Engraulidae and Gerreidae found to be dominant families in the study sites. Clupeidae and Gerreidae shown a wide larval dispersal area because they were collected at all study sites. These findings seem to indicate that the subtidal zone of Sampadi support more species of fish larvae.

Relationships of Native Desert Plants with Red Brome (Bromus rubens): Toward Identifying Invasion-Reducing Species

2011 ◽  
Vol 4 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Scott R. Abella ◽  
Donovan J. Craig ◽  
Lindsay P. Chiquoine ◽  
Kathryn A. Prengaman ◽  
Sarah M. Schmid ◽  
...  
Keyword(s):  
Mojave Desert ◽  
Native Species ◽  
Strongly Correlated ◽  
Annual Grass ◽  
Desert Ecosystems ◽  
Red Brome ◽  
Bromus Rubens ◽  
Competitive Abilities ◽  
Practical Implications

AbstractThe interactions between native and exotic species occur on a continuum from facilitative to competitive. A growing thrust in invasive species science is differentiating where particular native species occur along this continuum, with practical implications for identifying species that might reduce the invasibility of ecosystems. We used a greenhouse experiment to develop a competitive hierarchy of 27 native species with red brome, an invasive annual grass in the arid lands of the southwestern United States, and a field study to assess in situ responses of brome to native perennial species in the Mojave Desert. Native species most competitive with brome in the competition experiment included the annuals Esteve's pincushion and western fiddleneck and the perennials eastern Mojave buckwheat, sweetbush, and brittlebush, which reduced brome biomass to 49 to 70% of its grown-alone amount. There was no clear difference in competitive abilities with brome between annual and perennial natives, and competiveness was not strongly correlated (r = 0.15) with the biomass of the native species. In the field, sweetbush and brittlebush supported among the least cover of brome, suggesting congruence of the strong early competitive abilities of these species with in situ patterns of brome distribution. At the other extreme, brome attained its highest average cover (19%) below littleleaf ratany, significantly greater than all but 3 of the 16 species evaluated. Cover by brome was only weakly related (r = 0.19) to the area of the perennial canopy, suggesting that factors other than the sizes of perennial plants were linked to differences in brome cover among species. Results suggest that (1) interactions with brome differ substantially among native species, (2) these interactions are not as closely linked to biomass production as in more temperate regions, and (3) there is potential for identifying native species that can reduce invasion of desert ecosystems.

scholarly journals Estimating the Four-Dimensional Structure of the Southern Ocean Using Satellite Altimetry

2011 ◽  
Vol 28 (4) ◽  
pp. 548-568 ◽  
Author(s):  
A. J. S. Meijers ◽  
N. L. Bindoff ◽  
S. R. Rintoul
Keyword(s):  
Southern Ocean ◽  
Satellite Altimetry ◽  
Velocity Structure ◽  
Velocity Fields ◽  
Optimal Interpolation ◽  
Dimensional Structure ◽  
Strongly Correlated ◽  
Circumpolar Current ◽  
The Antarctic

Abstract A gravest empirical mode (GEM) projection of temperature and salinity fields over the circumpolar Southern Ocean is presented and is used in combination with satellite altimetry to produce gridded, full-depth, time-evolving temperature, salinity, and velocity fields. Optimal interpolation of historical hydrography, including Argo floats, is used to produce GEM projections of the circumpolar temperature and salinity fields. Parameterizing these fields by dynamic height allows the use of altimetric SSH values from 1992–2006 to create synoptic temperature and salinity fields at weekly intervals on a ⅓° grid at 36 depth levels. The satellite-derived temperature and salinity fields generally capture over 90% of the property variance below the thermocline, with RMS residuals of 1.16°C and 0.132 in salinity at the surface, decreasing to less than 0.45°C and 0.05 below 500 dbar. The combination of altimetry with the GEM fields allows the resolution of the subsurface structure of the filamentary fronts and eddy features. Velocity fields derived from the time-evolving temperature and salinity fields reproduce the Antarctic Circumpolar Current (ACC) velocity structure well, and are strongly correlated (r > 0.7) with in situ measurements from current meters and drifters, with RMS velocity residuals of 4.8–14.8 cm−1 in the Subantarctic Front.

Integrative molecular profiling and response to chemotherapy on the COMPASS trial.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 188-188 ◽  
Author(s):  
Grainne M. O'Kane ◽  
Sandra Fischer ◽  
Rob Denroche ◽  
Gun Ho Jang ◽  
Amy Zhang ◽  
...  
Keyword(s):  
Locally Advanced ◽  
Chemotherapy Resistance ◽  
Predictive Biomarker ◽  
Genetic Alterations ◽  
Molecular Characteristics ◽  
Strongly Correlated ◽  
First Line ◽  
Tumor Biopsy ◽  
Response To Chemotherapy

188 Background: Predictive mutational and transcriptional features in advanced PDAC are needed for improved patient stratification and treatment selection. Methods: Patients (pts) on the COMPASS trial with advanced PDAC are prospectively recruited prior to first-line chemotherapy for WGS and RNAseq. Tumor tissue undergoes enrichment by laser capture microdissection with genomic analyses available within eight wks. Tumor responses and clinical outcomes in this maturing cohort were correlated with molecular characteristics. Results: 157 pts underwent a tumor biopsy between Dec 2015 and Jul 2018 with over 95% success in achieving results. 141 genomes have been reported in pts planned to receive chemotherapy; the median time from biopsy to report was 35.5 days. In the ITT population,118 pts are summarised for first-line response. The median age was 63 yrs (29-81), 55% were male, and 16% had locally advanced disease. 66 (56%) received modified FFX as first-line treatment. 25 (21%) tumors displayed the Moffitt basal-like RNA signature which associated with chemotherapy resistance, with tumor shrinkage mainly observed in the classical RNA subtype (p = 0.002). GATA6 expression (log10 scale) clearly separated Moffitt subgroups with classical tumors exhibiting high expression (p < 0.0001). GATA6 in situ hybridization strongly correlated with RNAseq, (r = 0.89, p < 0.001) with strong correlation also seen with GATA6 IHC. The median overall survival (OS) in the classical group was 8.5 mths vs. 6.6 mths in the basal-like group (HR 0.53, 95% CI 0.32-0.89 p = 0.015). In those treated with mFFX, median OS was 10.1mths in classical versus 6.6mths in the basal-like subtypes, (HR 0.32, 95% CI 0.16-0.63, p=0.001). 30% of pts had potentially actionable genetic alterations including BRAF variants (n = 4) and an NTRK3-EML4 fusion in KRAS WT tumors (8%). Signatures of homologous recombination deficiency (HRD) were found in seven pts; two additional pts with BRCA germline variants did not exhibit somatic HRD hallmarks. Conclusions: Subsets of pts with advanced PDAC have actionable variants including those with HRD signatures and patients with KRAS WT tumors. GATA6 is a putative predictive biomarker of transcriptomic subgroups which should be incorporated in clinical trials. Clinical trial information: NCT02750657.

Immunohistochemistry accurately predicts FGFR3 aberrant expression and t(4;14) in multiple myeloma

Blood ◽  
2005 ◽  
Vol 106 (1) ◽  
pp. 353-355 ◽  
Author(s):  
Hong Chang ◽  
A. Keith Stewart ◽  
Xiao Ying Qi ◽  
Zhi Hua Li ◽  
Qi Long Yi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Fibroblast Growth Factor Receptor ◽  
Immunoglobulin A ◽  
Growth Factor Receptor ◽  
Progression Free Survival ◽  
Strongly Correlated ◽  
Aberrant Expression ◽  
Bone Marrow Biopsies ◽  
Free Survival

The t(4;14) translocation detected by fluorescence in situ hybridization (FISH) is an independent prognostic factor for an adverse outcome of multiple myeloma (MM). Because t(4;14) uniquely results in fibroblast growth factor receptor 3 (FGFR3) expression, decalcified, paraffin-embedded bone marrow biopsies were immunostained for FGFR3, and its expression was correlated with the t(4;14) status. FISH detected t(4;14) in 16 (19%) of 85 MM patient specimens, and immunocytochemistry detected aberrant FGFR3 expression in 13 (15%). Twelve (75%) t(4;14)-positive cases expressed FGFR3, and 12 (92%) FGFR3-positive cases harbored a t(4;14). FGFR3 expression and t(4;14) were strongly correlated (P &lt; .001). FGFR3 expression by immunohistochemistry was associated with the immunoglobulin A (IgA) isotype (P &lt; .001), a shorter progression-free survival (median, 11.5 versus 25.8 months; P &lt; .001), and a shorter overall survival (median, 19.2 versus 46.3 months; P &lt; .001).

scholarly journals Strong horizontal and vertical connectivity in the coral Pocillopora verrucosa from Ludao, Taiwan, a small oceanic island

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258181
Author(s):  
Stéphane de Palmas ◽  
Derek Soto ◽  
Ming-Jay Ho ◽  
Vianney Denis ◽  
Chaolun Allen Chen
Keyword(s):  
Population Structure ◽  
Larval Dispersal ◽  
Oceanic Island ◽  
Genetic Connectivity ◽  
Eastern Coast ◽  
Genetic Clustering ◽  
The Right ◽  
Depth Ranges ◽  
Pocillopora Verrucosa ◽  
F Statistics

Mesophotic habitats could be sheltered from natural and anthropogenic disturbances and act as reproductive refuges, providing propagules to replenish shallower populations. Molecular markers can be used as proxies evaluating the connectivity and inferring population structure and larval dispersal. This study characterizes population structure as well as horizontal and vertical genetic connectivity of the broadcasting coral Pocillopora verrucosa from Ludao, a small oceanic island off the eastern coast of Taiwan. We genotyped 75 P. verrucosa specimens from three sites (Gongguan, Dabaisha, and Guiwan) at three depth ranges (Shallow: 7–15 m, Mid-depth: 23–30 m, and Deep: 38–45 m), spanning shallow to upper mesophotic coral reefs, with eight microsatellite markers. F-statistics showed a moderate differentiation (FST = 0.106, p<0.05) between two adjacent locations (Dabaisha 23–30 and Dabaisha 38–45 m), but no differentiation elsewhere, suggesting high levels of connectivity among sites and depths. STRUCTURE analysis showed no genetic clustering among sites or depths, indicating that all Pocillopora individuals could be drawn from a single panmictic population. Simulations of recent migration assigned 30 individuals (40%) to a different location from where they were collected. Among them, 1/3 were assigned to deeper locations, 1/3 to shallower populations and 1/3 were assigned to the right depth but a different site. These results suggest high levels of vertical and horizontal connectivity, which could enhance the recovery of P. verrucosa following disturbances around Ludao, a feature that agrees with demographic studies portraying this species as an opportunistic scleractinian.

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