Application of Empirical Size-Dependent Models of Larval Fish Vital Rates to the Study of Production: Accuracy and Association with Adult Stock Dynamics in a Comparison among Species

1993 ◽  
Vol 50 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Pierre Pepin
Keyword(s):  
Empirical Model ◽  
Larval Fish ◽  
Fish Larvae ◽  
Vital Rates ◽  
Larval Phase ◽  
Grand Banks ◽  
Size Dependent ◽  
Dependent Change ◽  
Class Strength ◽  
Empirical Size

A simple model of the size-dependent change in biomass of a cohort of fish larvae based on empirically derived relationships for growth and mortality is presented. Model predictions are compared with data for seven species of larval fish sampled on the Grand Banks of Newfoundland in 1980–81 to determine (1) whether the slope of the size-dependent larval biomass curve is significantly different from the general empirical model, and (2) whether the slope and intercept of the biomass curve are reflective of relative year-class strength and stock abundance, respectively. The slope of the size-dependent larval biomass curve is not significantly different from that predicted by the model in six of seven cases. The slope of the larval biomass curve is not significantly correlated with standardized year-class strength. The height of the curve (i.e. intercept) is only weakly associated with adult stock biomass. I conclude from this set of observations that estimates of larval fish vital rates may not be measured with sufficient accuracy to permit detection of a significant association between deviations from the general empirical model and the factors that may influence survivorship during the larval phase in a comparison across species.

Disentangling the effects of size-dependent encounter and susceptibility to predation with an individual-based model for fish larvae

1999 ◽  
Vol 56 (9) ◽  
pp. 1562-1575 ◽  
Author(s):  
A R Paradis ◽  
M Pépin ◽  
P Pepin
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Critical Element ◽  
Selective Mortality ◽  
Larval Phase ◽  
Size Dependent ◽  
Synchronous Spawning ◽  
Fish Cohort ◽  
Empirical Size

We investigated the effects of size-dependent encounter and susceptibility, the role of variation in the size distribution of predators, and the timing of prey-predator interaction during the larval phase in shaping the length frequency distribution of surviving fish larvae. These analyses based on general empirical size-dependent relationships may have broad implications in understanding larval fish cohort dynamics. We demonstrated that the formulations of encounter and susceptibility to predation counteract each other, an increased range of predator sizes reduces only slightly the evidence for size-selective mortality, and synchronous spawning and hatching events have the potential to yield strong size-selective mortality of a cohort of fish larvae. The important factors in generating size-selective mortality are either the timing of encounters between fish larvae and their predators or high mortality rates. We demonstrated a direct relationship between the potential of size-selective mortality and the overall mortality rate of the cohort. We suggest that it may be difficult to detect the effect of size-dependent processes in the field. A better understanding of the factors influencing encounter represents a critical element in extrapolating laboratory studies of predation to the field.

scholarly journals Poor taxonomical knowledge of larval fish prey preference is impeding our ability to assess the existence of a “critical period” driving year-class strength

2013 ◽  
Vol 71 (8) ◽  
pp. 2042-2052 ◽  
Author(s):  
Dominique Robert ◽  
Hannah M. Murphy ◽  
Gregory P. Jenkins ◽  
Louis Fortier
Keyword(s):  
Larval Stage ◽  
Critical Period ◽  
Prey Availability ◽  
Larval Fish ◽  
Prey Preference ◽  
Vital Rates ◽  
Prey Selectivity ◽  
Fish Prey ◽  
Taxonomical Knowledge ◽  
Class Strength

Abstract Despite 100 years of research testing the link between prey availability during the larval stage and year-class strength, field-based evidence for Hjort's “critical period” hypothesis remains equivocal. Here, we argue that a minority of past studies have relied on sufficient taxonomical knowledge of larval fish prey preference to reveal the potential effects of variability in zooplankton prey production on larval vital rates and year-class strength. In contrast to the juvenile and adult stages, larval fish diet and prey field are often poorly resolved, resulting in the inclusion of zooplankton taxa that do not actually contribute to the diet as part of the prey field considered by fisheries scientists. Recent studies have demonstrated that when accounting for prey selectivity, the expected positive relationships between preferred prey availability and larval feeding success, growth and survival are revealed. We strongly recommend that laboratories conducting research on larval fish trophodynamics take prey selectivity into account and acquire the necessary taxonomic expertise for providing valid assessments of the influence of prey availability on larval vital rates. We make the prediction that the proportion of studies supporting the existence of a “critical period” will increase proportionally to the progress of knowledge on prey preference during the early larval stage.

scholarly journals Fish larvae exploit edge vortices along their dorsal and ventral fin folds to propel themselves

2016 ◽  
Vol 13 (116) ◽  
pp. 20160068 ◽  
Author(s):  
Gen Li ◽  
Ulrike K. Müller ◽  
Johan L. van Leeuwen ◽  
Hao Liu
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Bony Fish ◽  
The Body ◽  
Functional Explanation ◽  
Image Velocimetry ◽  
Median Fins

Larvae of bony fish swim in the intermediate Reynolds number ( Re ) regime, using body- and caudal-fin undulation to propel themselves. They share a median fin fold that transforms into separate median fins as they grow into juveniles. The fin fold was suggested to be an adaption for locomotion in the intermediate Reynolds regime, but its fluid-dynamic role is still enigmatic. Using three-dimensional fluid-dynamic computations, we quantified the swimming trajectory from body-shape changes during cyclic swimming of larval fish. We predicted unsteady vortices around the upper and lower edges of the fin fold, and identified similar vortices around real larvae with particle image velocimetry. We show that thrust contributions on the body peak adjacent to the upper and lower edges of the fin fold where large left–right pressure differences occur in concert with the periodical generation and shedding of edge vortices. The fin fold enhances effective flow separation and drag-based thrust. Along the body, net thrust is generated in multiple zones posterior to the centre of mass. Counterfactual simulations exploring the effect of having a fin fold across a range of Reynolds numbers show that the fin fold helps larvae achieve high swimming speeds, yet requires high power. We conclude that propulsion in larval fish partly relies on unsteady high-intensity vortices along the upper and lower edges of the fin fold, providing a functional explanation for the omnipresence of the fin fold in bony-fish larvae.

scholarly journals Osmotic induction improves batch marking of larval fish otoliths with enriched stable isotopes

2014 ◽  
Vol 71 (9) ◽  
pp. 2530-2538 ◽  
Author(s):  
Emmanuel de Braux ◽  
Fletcher Warren-Myers ◽  
Tim Dempster ◽  
Per Gunnar Fjelldal ◽  
Tom Hansen ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Salmo Salar ◽  
Larval Fish ◽  
Fish Larvae ◽  
Cost Effective ◽  
Industrial Applications ◽  
Chemical Markers ◽  
Potential Applications ◽  
Recent Method ◽  
Batch Marking

Abstract Otolith marking with enriched stable isotopes via immersion is a recent method of batch marking larval fish for a range of research and industrial applications. However, current immersion times and isotope concentrations required to successfully mark an otolith limit the utility of this technique. Osmotic induction improves incorporation and reduces immersion time for some chemical markers, but its effects on isotope incorporation into otoliths are unknown. Here, we tested the effects of osmotic induction over a range of different isotope concentrations and immersion times on relative mark success and strength for 26Mg:24Mg, 86Sr:88Sr and 137Ba:138Ba on Atlantic salmon (Salmo salar) larvae. 71% and 100% mark success were achieved after 1 h of immersion for 86Sr (75 µg L−1) and 137Ba (30 µg L−1) isotopes, respectively. Compared with conventional immersion, osmotic induction improved overall mark strength for 86Sr and 137Ba isotopes by 26–116%, although this effect was only observed after 12 h of immersion and predominately for 86Sr. The results demonstrate that osmotic induction reduces immersion times and the concentrations of isotope required to achieve successful marks. Osmotically induced isotope labels via larval immersion may prove a rapid and cost-effective way of batch marking fish larvae across a range of potential applications.

scholarly journals Feeding of the Brycon cephalus, Triportheus elongatus and Semaprochilodus insignis (osteichthyes, characiformes) larvae in Solimões/Amazonas River and floodplain areas.

2002 ◽  
Vol 32 (3) ◽  
pp. 499-499 ◽  
Author(s):  
Rosseval Galdino LEITE ◽  
Carlos A.R.M. ARAUJO-LIMA
Keyword(s):  
Food Item ◽  
Prey Size ◽  
Larval Fish ◽  
Fish Larvae ◽  
Trophic Relations ◽  
Fish Feeding ◽  
Important Species ◽  
Flooded Forests ◽  
Commercially Important

Information on larval fish feeding is essential for understanding their trophic relations, including the management in conditions totally or partially controlled by humans. An experiment was designed to evaluate the larval diets of three commercially important species. Four varzea-lakes and the adjacent river were sampled with bongo and hand nets from January 1993 to November 1995. Larval diets were evaluated by length-classes and capture sites, and were tested by two factor ANOVA. The larvae were feeding in all habitats, except in the flooded forests. The three species had different diets, which varied with their length and lake. The rotifers were the main initial food item of the three species, replaced by fish larvae in Brycon cephalus, cladocerans in Triportheus elongatus and detritus in Semaprochilodus insignis. The increase of the ingestion limit, as the larvae grew, was higher than the increase in the consumed prey size for the three species.

scholarly journals Long-term changes of ichthyoplankton communities in an Iberian estuary are driven by varying hydrodynamic conditions

2020 ◽  
Author(s):  
M Monteiro ◽  
U M Azeiteiro ◽  
F Martinho ◽  
M A Pardal ◽  
A L Primo
Keyword(s):  
Environmental Variability ◽  
Larval Fish ◽  
Fish Larvae ◽  
Climate Change Impacts ◽  
Variable Structure ◽  
Local Environment ◽  
Strong Relationship ◽  
Marine Species ◽  
Economic Implications ◽  
Species Dominance

Abstract Ichthyoplankton assemblages are key components of estuaries worldwide, playing a vital role as nurseries for fish larvae. Nonetheless, estuaries can be highly affected by ongoing climate change. Impacts of climate variability on ichthyoplankton assemblages will have consequences for marine pelagic food webs and fish populations biology, namely recruitment. This study aims to investigate the influence of environmental variability on an interannual abundance of ichthyoplankton assemblages of the Mondego estuary (Portugal). For this, an ichthyoplankton sampling programme of 13 years (2003–2015) along six distinct sampling stations was analysed to evaluate spatial, seasonal and interannual changes of ichthyoplankton distribution over periods of wet, regular and dry conditions. The ichthyoplanktonic community was dominated by Pomatoschistus spp. across all seasons and conditions, with higher larval abundances during summer and spring. Main changes were related to species seasonality and phenology as well as an increase in the number of marine species during extreme events. The larval fish community showed a strong relationship with the regional and local environment over the study, presenting a distinct yet highly variable structure during the 2009–2013 period. Reported changes will likely trigger major changes in species dominance and abundance, with clear ecological and socio-economic implications.

Ontogeny of Otolith Formation in Two Demersal Estuarine Reef Fishes

2018 ◽  
Vol 134 (3-4) ◽  
pp. 1-9 ◽  
Author(s):  
Kyle J Hoffman ◽  
Juliana M Harding
Keyword(s):  
Oyster Reef ◽  
Larval Fish ◽  
Fish Larvae ◽  
Reef Fishes ◽  
Allometric Model ◽  
Benthic Habitats ◽  
Ambient Temperatures ◽  
Total Length ◽  
Naked Goby ◽  
Gobiosoma Bosc

Abstract Planktonic reef fish larvae locate and orient to reefs during settlement. Consequently, metamorphosis occurs in appropriate juvenile and/or adult habitats. Larval fish use otoliths for hearing (sagittae and asterisci) as well as equilibrium (lapilli) required for directional swimming. Striped blenny (Chasmodes bosquianus) and naked goby (Gobiosoma bosc) larvae, settled individuals, and juveniles were used to describe otolith ontogeny from hatching through settlement, the transition from pelagic to benthic habitats, and metamorphosis. Larvae hatched from nests collected in North Inlet estuary, SC, were cultured from May through July in 2012 and 2013 at ambient temperatures. Sagittae and lapilli were present at hatching in both species. Asterisci were only observed in settlement (gobies and blennies) or metamorphosis (blennies) stage fishes, regardless of age (days post-hatch). Otoliths within a pair were symmetrical. Fish total length increased faster than sagittae otolith length in settlement stage blennies and postflexion gobies. The allometric model explained ∼90% of the variability in sagittae otolith length with total length for both species. Settlement occurred 15–20 days post-hatch in striped blennies and 19–27 days post-hatch in naked gobies. Asterisci were found in 100% of settlement stage striped blennies and 67% of naked gobies. We hypothesize that the presence of asterisci in settlement stage demersal oyster reef fishes facilitates identification of and orientation to suitable settlement habitats thereby enhancing recruitment success.

Influence of tidal phase and circulation on larval fish distribution in a partially mixed estuary, Corral Bay, Chile

2003 ◽  
Vol 83 (1) ◽  
pp. 217-222 ◽  
Author(s):  
Cristian A. Vargas ◽  
Sandro E. Araneda ◽  
Guillermo Valenzuela
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Salt Water ◽  
Larval Density ◽  
Abundant Species ◽  
Fish Distribution ◽  
Older Individuals ◽  
Austral Spring ◽  
Tidal Front ◽  
Tidal Phase

The influence of circulation on abundance patterns of larval fish was compared at different phases of the tide in the vicinity of an estuarine front in Corral Bay, Chile during austral spring. Greatest differences in water salinity were found across the frontal region on ebb tides. Because rainfall was low, density differences were primarily due to tidal intrusion of salt water. Larval density was relatively low during both sampling periods with Strangomera bentincki, Oodntesthes regia laticlavia, Gobiesox marmoratus and Hypsoblennius sordidus as the most abundant species. Total ichthyoplankton was always higher near the tidal front (Stations 2 and 3). Spatial distribution in relation to tidal phase showed different patterns for the most abundant fish larval species. Circulation and larval distribution revealed that the bay was a source of young fish larvae but older individuals could also be recruited in and retained there. Results show that the front could act as a physical boundary for larvae transported from offshore through specific mechanism of circulation related with the tidal regime.

Oceanographic scenario and fish larval distribution off Guinea-Bissau (north-west Africa)

2014 ◽  
Vol 95 (3) ◽  
pp. 435-452 ◽  
Author(s):  
M.P. Jiménez ◽  
R.F. Sánchez-Leal ◽  
C. González ◽  
E. García-Isarch ◽  
A. García
Keyword(s):  
Surface Waters ◽  
Larval Fish ◽  
Fish Larvae ◽  
Inner Shelf ◽  
North West ◽  
Guinea Bissau ◽  
Larval Distribution ◽  
Océanographic Survey ◽  
Continental Runoff ◽  
Abundance And Diversity

This paper describes the hydrography and the larval fish assemblage of Guinea Bissau waters, and analyses the spatial distribution of the main families in relation to the oceanographic features of the area. Data were obtained during an oceanographic survey, undertaken between October and November 2008. In addition to 98 demersal fishing hauls, a total of 33 stations, located between 20 and 1000 m depth, were sampled for hydrography and ichthyoplankton. Data showed that Guinea-Bissauan surface waters are characterized by a strong thermohaline front that flows parallel to the bathymetry of the area. Warm surface waters (SST > 29°C) occupy the inner shelf, and colder (SST < 26°C), chlorophyll-a-rich waters take over the shelf break. Continental runoff seems responsible for the low salinity of the inner-shelf waters whereas the colder types bear thermohaline features typical of tropical Atlantic waters. These features define a scenario which favours the development of fish early life stages, reflected in the high abundance and diversity of fish larvae recorded. A total of 84 taxa of fish larvae were identified. Only the family Clupeidae accounted for 54.8% of the sampled larvae. Other important families were Carangidae (8.8%), Sparidae (8.4%) and Myctophidae (5.9%).

Escape Responses of Herring Larvae to Visual Stimuli

1989 ◽  
Vol 69 (3) ◽  
pp. 647-654 ◽  
Author(s):  
R.S. Batty
Keyword(s):  
Startle Response ◽  
Larval Fish ◽  
Fish Larvae ◽  
Adult Population ◽  
Juvenile Fish ◽  
Reciprocal Inhibition ◽  
Contralateral Side ◽  
The Body ◽  
Different Types ◽  
Trunk Musculature

Predation is now considered the main cause of mortality in larval and juvenile fish (Hunter, 1984) and is therefore the most important factor controlling recruitment to the adult population. Marine fish larvae are prey for many different types of predator including medusae, crustaceans and larger fish. When predatory attacks are sensed both adult and larval fish may respond by making a 'C-start', a very fast, simultaneous contraction of the trunk musculature that deforms the body into a C-shape within 20 ms (Eaton & Hackett, 1984). This startle response is mediated by the Mauthner cells, a pair of prominent neurones in the hind brain or by other reticulo-spinal cells located in the same region. As a result of reciprocal inhibition and decussation of the cell axon, stimulation on one side of the body results in contraction of all the muscle on the contralateral side.

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