scholarly journals Ontogenetic and intraspecific variability in otolith shape of anchoveta (Engraulis ringens) used to identify demographic units in the Pacific Southeast off Chile

2019 ◽  
Vol 70 (12) ◽  
pp. 1794 ◽  
Author(s):  
Francisco Cerna ◽  
Juan Carlos Saavedra-Nievas ◽  
Guido Plaza-Pasten ◽  
Edwin Niklitschek ◽  
Beatriz Morales-Nin
Keyword(s):  
Intraspecific Variability ◽  
Additive Models ◽  
Fish Length ◽  
Adult Fish ◽  
Otolith Shape ◽  
Total Percentage ◽  
The Pacific ◽  
Sampling Zone ◽  
Engraulis Ringens ◽  
Fourier Harmonics

The phenotypical variability in otolith shape of anchoveta (Engraulis ringens) was analysed in three zones (I, II and III) from north to south along the Chilean coast, using juvenile and adult fish. Generalised additive models were used to analyse shape indices and canonical discriminant analysis was used to analyse elliptical Fourier harmonics. The form factor and ellipticity indices varied significantly among the three zones, whereas roundness, circularity and rectangularity indices only showed differences between Zones I and III. Fourier reconstructed outlines for five ontogenetic stages suggested important differences among sampling zones, which were larger for sampling Zone III, where, at the same fish length, otoliths were smaller than those sampled in Zones I and II, at least at the pre-recruit stage. Elliptical Fourier descriptors showed significant differences among the three units, with a total percentage of correct classifications for juveniles of 89 and 74% for raw data and cross-validated cases respectively, compared with >85 and ~65% respectively for adult fish. The results support the hypothesis that juveniles and adults of anchoveta have remained segregated throughout their entire, or at least a fraction of, their life cycle, mainly between the extreme northward and southward zones.

Regional Differences in Otolith Morphology of the Deep Slope Red Snapper Etelis carbunculus

1992 ◽  
Vol 49 (4) ◽  
pp. 795-804 ◽  
Author(s):  
M. Kimberly Smith
Keyword(s):  
Growth Rate ◽  
Regional Differences ◽  
Maximum Size ◽  
Dry Weight ◽  
French Polynesia ◽  
Red Snapper ◽  
Fish Length ◽  
Otolith Shape ◽  
The Pacific ◽  
Wide Range

Sagittal otoliths from four populations of the Pacific deep slope red snapper Etelis carbunculus Cuvier were compared using Fourier descriptors and other shape indices, linear proportions, and dry weight. Otoliths from Hawaii, Vanuatu, Fiji and French Polynesia and a small number from the Commonwealth of the Northern Marianas Islands (NMI) were examined. Regional shape and weight characteristics were distinguishable, despite the wide range of individual variation and limited available size range from some regions. Size-specific differences in otolith shape were found for the four regions for which a sufficient sample was available. Otoliths from Hawaii, French Polynesia, and NMI showed a significant shape affinity. Otoliths from Fiji and Vanuatu were similarly shaped and were distinct from those from the other three regions. Interregional otolith shape affinities for the stocks examined parallel similarities in maximum size and growth rate from the literature, suggesting that growth rate may influence otolith shape. Observed trends in otolith weight as a function of fish length support growth-related regional differences in otolith shape.

scholarly journals Identificación de stocks de Engraulis ringens en Chile utilizando morfometría de otolitos

2019 ◽  
Vol 54 (1) ◽  
pp. 144
Author(s):  
Cecilia Machuca ◽  
Francisco Cerna ◽  
Lizandro Muñoz
Keyword(s):  
Discriminant Analysis ◽  
Shape Analysis ◽  
Fourier Coefficients ◽  
Canonical Discriminant Analysis ◽  
Contour Analysis ◽  
Otolith Shape ◽  
Elliptical Fourier Analysis ◽  
Shape Indices ◽  
Engraulis Ringens ◽  
Fourier Harmonics

Anchovy (Engraulis ringens) population units were analyzed in three zones off the coast of Chile: 1: Arica-Iquique, 2: Coquimbo and 3: Talcahuano-Valdivia from samples obtaineds during the 2012 spawning season. We used 50 left sagittae otoliths from each zone to perform a morphometric analysis, which included basic measurements, shape indexes and contour analysis (elliptical Fourier analysis). A MANOVA and Tukey multiple comparison analyses, applied on basic measures and shape indexes showed significant differences between zone 3 and zones 1 and 2. A classification by Canonical Discriminant analysis of elliptical Fourier harmonics, indicated significant differences among zones. It is concluded, therefore, that otolith shape analysis could be used to discriminate population units of Engraulis ringens. Better results were achieved using elliptic Fourier coefficients than using only shape indices.

scholarly journals Contribution of different spawning components to the mixed stock fishery for cod in Icelandic waters

2007 ◽  
Vol 64 (9) ◽  
pp. 1749-1759 ◽  
Author(s):  
Ingibjörg G. Jónsdóttir ◽  
Gudrun Marteinsdottir ◽  
Steven E. Campana
Keyword(s):  
Maximum Likelihood ◽  
Gadus Morhua ◽  
Fish Length ◽  
Minor Importance ◽  
Otolith Chemistry ◽  
Marine Science ◽  
Otolith Shape ◽  
Mixed Stock ◽  
Feeding Grounds ◽  
Icelandic Waters

Abstract Jónsdóttir, I. G., Marteinsdottir, G., and Campana, S. E. 2007. Contribution of different spawning components to the mixed stock fishery for cod in Icelandic waters. – ICES Journal of Marine Science, 64: 000–000. Otolith chemistry and length-at-age were used to estimate the contribution of different spawning components to the harvested stock of cod (Gadus morhua) at two of their main feeding grounds northwest and east of Iceland. Spawning cod were sampled at different spawning locations around Iceland in spring of 2002 and 2003. Significant differences were detected between cod from the different spawning locations. Cod of unknown stock origin were also sampled at two of the main feeding grounds in October of the same years. Analyses based on maximum likelihood were used to estimate the proportion of each spawning group in the mixed stock catches using otolith chemistry and fish length-at-age. Attempts to use otolith shape to estimate the contribution of the spawning groups to the mixed harvested stock were, however, unsuccessful. The results indicated that spawning locations northwest and north of Iceland, as well as in water deeper than 125 m south of Iceland, contributed the most to the harvested stock. Cod spawning shallower than 125 m south of Iceland did not contribute to the feeding grounds in October of 2002 and 2003. Therefore, exploitation of the feeding stock mixtures seems to be based on spawning components that have previously been considered to be of minor importance to the Icelandic cod stock.

scholarly journals Th e Relationship Between Fish Length and Otolith Size and Weight of the Australian Ancnovy, En-graulis australis (Clupeiformes, Engraulidae), Retrieved from the Food of the Australasian Gannet, Morus serrator (Suliformes, Sulidae), Hauraki Gulf, New Zealand

Zoodiversity ◽  
2021 ◽  
Vol 55 (4) ◽  
pp. 331-338
Author(s):  
L. A. Jawad ◽  
N. J. Adams
Keyword(s):  
New Zealand ◽  
Fish Length ◽  
Linear Regression Models ◽  
The Pacific ◽  
Ocean Region ◽  
Length Width ◽  
The Pacific Ocean ◽  
Relationship Of ◽  
Morus Serrator ◽  
Otolith Size

Relationships between fish length and otolith length, width and mass were examined in the Australian anchovy Engraulis australis (White, 1790) recovered from the food of Gannet examined from colonies at islands of Horuhoru Rock and Mahuki Islands in the Hauraki Gulf, New Zealand. The relationships between otolith length- fish total length (TL), otolith-weight-TL, and otolith-width-TL were investigated by means of non-linear regression models (TL = 0.54 OL 16.86, TL = 4.39 OW 7.61 and TL = 26.19 OWe 2.2). This study characterizes the first reference available on the relationship of fish size and otolith size and weight for E. australis obtained from bird’s food in the Pacific Ocean region

scholarly journals Otolith shape analysis as a tool for stock identification of the southern blue whiting, Micromesistius australis

2017 ◽  
Vol 41 (3) ◽  
pp. 479-489
Author(s):  
Javier Leguá ◽  
Guido Plaza ◽  
Darío Pérez ◽  
Alexander Arkhipkin
Keyword(s):  
Shape Analysis ◽  
Reproductive Period ◽  
Falkland Islands ◽  
Southern Chile ◽  
Mean Values ◽  
Otolith Shape ◽  
Otolith Shape Analysis ◽  
Blue Whiting ◽  
The Pacific ◽  
Economic Zone

The southern blue whiting, Micromesistius australis (Norman, 1937), is an important demersal resource associated with the slope and continental shelf of southern Chile, Argentina and the Malvinas/Falkland Islands. Recent studies have reported schools of adult fish from Atlantic waters migrating along the southern Chilean coast in mid-winter, moving northwards to spawn in August (47º-51ºS), and then returning to Atlantic waters, presumably to feed. The migratory pattern suggests the presence of one or more stock units associated with the South American coast. In the present study, “otolith morphometry” is used to determine the stock structure of M. australis based on applications of basic size descriptors (SDs) (area, perimeter and otolith size), shape indices (SIs) (circularity, squareness, shape factor, roundness, ellipticity), and normalised elliptical Fourier descriptors (NEFDs). Samples were collected during the winter and spring of 2010, during the reproductive period, in the economic zone of southern Chile (36º-57ºS), in the Pacific Ocean and around the Falkland Islands economic zone (50º-52ºS) in the Atlantic Ocean. Analyses were conducted to include the effects of size, sex and age. A stepwise canonical discriminant analysis showed that fish were successfully discriminated with SDs, SIs and NEFDs. In this analysis, 86.4% and 70.1% of the fish were correctly classified as belonging to the Atlantic and Pacific stocks, respectively. A multivariate analysis of variance showed that the mean values of the NEFDs, SDs, and SIs did not vary significantly between sexes within areas (P > 0.05), but varied significantly between the Pacific and Atlantic oceans (P < 0.05). These results highlighted that otolith shape analysis can be a useful tool to evaluate the potential level of mixing in feeding areas where both stocks, the Pacific and Atlantic units, are expected to co-occur.

A fishery-independent assessment of an overfished rockfish stock, cowcod (Sebastes levis), using direct observations from an occupied submersible

2007 ◽  
Vol 64 (12) ◽  
pp. 1795-1804 ◽  
Author(s):  
Mary M Yoklavich ◽  
Milton S Love ◽  
Karin A Forney
Keyword(s):  
Fishery Management ◽  
Line Transect ◽  
Fish Length ◽  
Conservation Areas ◽  
Direct Observations ◽  
Length Relationship ◽  
The Pacific ◽  
Mean Size ◽  
Precipitous Decline ◽  
Independent Assessment

A meaningful assessment of cowcod (Sebastes levis) has been conducted using visual, nonextractive, habitat-specific methods. Following the precipitous decline of rockfish (Sebastes spp.) stocks along the Pacific coast, it was evident that more effective methods were needed to assess several species in untrawlable habitats. Cowcod were surveyed within large Cowcod Conservation Areas (CCAs) off southern California using direct observations from the research submersible Delta over eight major offshore rocky banks in depths of 74 to 322 m. Maps of seafloor substratum and bathymetry were used to identify and quantify these areas. A line-transect analysis of fish counts, perpendicular distances of fish from the track line, lengths of survey tracks, and area of each rocky bank was used to estimate abundance. Biomass, calculated from abundance, fish length, and a weight–length relationship, varied with mean size of cowcod on these banks. These fishery-independent results have contributed to the recent assessment of cowcod by the Pacific Fishery Management Council. A time series of results from visual surveys is now necessary to evaluate a trend in cowcod biomass with respect to increased time of protection within the CCAs.

scholarly journals Ontogenetic Shifts in Home Range Size of a Top Predatory Reef-associated Fish (Caranx ignobilis): Implications for Conservation.

2020 ◽  
Author(s):  
Ryan Daly ◽  
John David Filmalter ◽  
Lauren R Peel ◽  
Bruce Quinten Mann ◽  
James Lea ◽  
...  
Keyword(s):  
Home Range ◽  
Juvenile Fish ◽  
Fork Length ◽  
Home Range Size ◽  
Range Size ◽  
Fish Length ◽  
Adult Fish ◽  
Convex Polygons ◽  
Spatial Management ◽  
Wide Range

Abstract Defining the home range of vulnerable species is critical for designing effective spatial management strategies. However, animal home ranges often change with ontogeny and quantifying the associated temporal and spatial changes is particularly challenging for mobile marine species. Here, we investigate how the space use of a top predatory reef-associated fish (Caranx ignobilis) scales with body size. We tagged 17 individuals, representing a wide range of sizes (40.5 – 120 cm fork length (FL)), with acoustic transmitters, and passively tracked them for over 3 years at a tropical island and atoll in the Republic of Seychelles, Western Indian Ocean. We found that a sheltered atoll environment was critical for juvenile fish (< 60 cm FL) that exhibited a shift in home range location and area as they matured into adults. Small (60 – 100 cm FL) and large (> 100 cm FL) adult fish appeared to favour shallow coral reefs and associated reef drop offs whilst sharing a similar core home range location. Large adult fish, however, utilized a greater diversity of habitat types and had significantly (p < 0.05) greater annual dispersal distances (mean = 35.29 km, max = 91.32 km) than small adults (mean = 13.72 km, max = 21.55 km). Additionally, the home range (represented by minimum convex polygons) of large adults (mean = 209.74 km2) was significantly (p < 0.05) larger than that of juveniles (mean = 38.73 km2) and small adults (77.32 km2) and there was a significant (p = 0.02) relationship between fish length and home range size, with fish length accounting for 32% of the home range size variance. Furthermore, tagged fish took up to 34 months (mean = 18.54) to utilize the full extent of their home range. The habitat shift and expansion in home range size throughout ontogeny exhibited by C. ignobilis in this study should be taken into account when designing effective spatial management plans for the species.

Optimal Environmental Window and Pelagic Fish Recruitment Success in Upwelling Areas

1989 ◽  
Vol 46 (4) ◽  
pp. 670-680 ◽  
Author(s):  
Philippe Cury ◽  
Claude Roy
Keyword(s):  
Wind Speed ◽  
Food Availability ◽  
Larval Survival ◽  
Pelagic Fish ◽  
Physical Constraints ◽  
Fish Recruitment ◽  
The Pacific ◽  
Engraulis Ringens ◽  
Upwelling Intensity ◽  
Wind Mixing

Food availability and physical constraints such as turbulence are now considered as important factors that affect larval survival and pelagic fish recruitment. In Ekman-type upwelling, vertical advection, new inputs of nutrients and turbulence are linked to wind speed. According to the literature, food availability for larvae is related to biological dynamics (primary production) up to a point where the biological processes are disturbed by physical processes (turbulence generated by wind mixing). This limitation does not exist for non Ekman-type upwelling where upwelling intensity is not correlated with wind speed. We hypothesize that relations between annual recruitments and upwelling intensity are dome shaped in Ekman-type upwellings and linear for non Ekman-type upwellings. A statistical method is used to analyse the form of the relationships between recruitments and upwelling indices or wind mixing. The recruitment of the Peruvian anchoveta (Engraulis ringens), of the Pacific sardine (Sardinops sagax caerulea) and of the West African sardines and sardinellas are thereby examined. Results show that for Ekman-type upwelling the annual recruitment increases with upwelling intensity until wind speed reaches a value of roughly 5–6 m∙s−1 and decreases for higher values. For a non Ekman-type upwelling the relationship between recruitment and upwelling intensity is linear. These results confirm the existence of an optimal environmental window for recruitment.

The effect of Kudoa paniformis infection on the reproductive effort of female Pacific hake

1998 ◽  
Vol 76 (12) ◽  
pp. 2285-2289 ◽  
Author(s):  
S A Adlerstein ◽  
M W Dorn
Keyword(s):  
Reproductive Effort ◽  
Detrimental Effect ◽  
Parasite Prevalence ◽  
Analysis Of Covariance ◽  
Fish Length ◽  
Intensity Of Infection ◽  
Oregon Coast ◽  
Merluccius Productus ◽  
The Pacific ◽  
Common Parasite

The effect of the myxosporidean Kudoa paniformis on the annual reproductive effort of the coastal stock of Pacific hake (Merluccius productus), on which it is a common parasite, is investigated. Female Pacific hake collected off the central Oregon coast in December 1988 were analyzed for prevalence and intensity of parasites. Reproductive effort was estimated by the number of yolked oocytes present in the ovaries immediately prior to spawning (potential annual fecundity), using the volumetric method. The effect of the parasite was evaluated through an analysis of covariance where fecundity was modeled as a function of fish length and parasite prevalence. An additional analysis of covariance evaluated the effect of the intensity of parasite infection on fecundity. Results show that the fecundity of Pacific hake is significantly reduced in the presence of K. paniformis infections and that the detrimental effect escalates with the intensity of infection. The potential effects on the population dynamics of the Pacific hake coastal stock are discussed.

Parasite Fauna of Kokanee Salmon (Oncorhynchus nerka) Introduced into Lake Huron

1974 ◽  
Vol 31 (11) ◽  
pp. 1818-1821 ◽  
Author(s):  
J. J. Collins ◽  
A. O. Dechtiar
Keyword(s):  
North America ◽  
Oncorhynchus Nerka ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Parasite Fauna ◽  
Lake Huron ◽  
Adult Fish ◽  
Kokanee Salmon ◽  
The Pacific ◽  
High Incidence

In a 7-yr study, the most common parasites of kokanee salmon (Oncorhynchus nerka) introduced to Lake Huron were the acanthocephalans Metechinorhynchus salmonis (in 61% of 228 adult fish examined) and Acanthocephalus jacksoni (15%) and the nematode Cystidicola stigmatura (41%). These also occurred in fish species netted along with kokanee, but many common parasites of other salmonids in Lake Huron were not harbored by kokanee. In addition to evidence of attack by sea lamprey (Petromyzon marinus), 18 species of parasites were found, 13 of which had not been previously recorded for kokanee in the Pacific drainages of North America. The high incidence of M. salmonis and C. stigmatura indicates that amphipods are commonly ingested by kokanee.

Sign in / Sign up

Export Citation Format

Share Document