Otolith Growth Patterns Research Articles

Inter-annual otolith growth pattern of adult small yellow croaker in the East China Sea and its response to environmental changes

Inter-annual otolith growth pattern of adult small yellow croaker in the East China Sea and its response to environmental changes

USING OTOLITH GROWTH PATTERN AS A TOOL FOR COMPARATIVE ANALYSIS OF OTOLITH GROWTH IN THE ARCTIC FLOUNDER LIOPSETTA GLACIALIS FROM ONEGA BAY OF THE WHITE SEA

One of the methods for studying otoliths which has been widely promoted around the world in recent decades is otolithometry. There has so far been no otolithometric research on pleuronectids in basins of Arctic seas other than the author’s own. The technique presented here can be used for a visual comparison of the growth rate of otoliths and fish as one of the methods for studying it based on the results of otolithometry. The comparison of the growth rate of fish otoliths would be the most informative in fish with pronounced sexual dimorphism. Annual ring sizes are especially clearly visible and comparable in the first years of life. When comparing area-specific patterns, fish of certain age are taken for each area. On the basis of the information received, growth rates are analyzed and compared among areas. The paper presents the methods of plotting an otolith growth pattern for illustrative study and comparison of growth rates in the Arctic flounder Liopsetta glacialis (Pleuronectidae) in different habitats. No such techniques have previously been published in the literature.

Irregular growth patterns in the otoliths of a short-lived forage fish do not reliably indicate reproductive history

Irregular growth patterns in fish otoliths are considered to reflect the energetic demands associated with reproduction and hence have been referred to as spawning zones or spawning checks. Here we evaluated the reliability of these checks for identifying the past reproductive history of capelin Mallotus villosus, a small pelagic fish found throughout the Northwest Atlantic that typically experiences high mortality associated with spawning. Ovarian histology was used to definitively identify females that had previously spawned via the presence of residual oocytes. Only half of the individuals confirmed to be recovering from a previous spawning episode were identified as having spawning checks in their otoliths, indicating that not all spawning episodes result in the formation of spawning checks. In addition, some individuals that appeared to be immature also had spawning checks, suggesting that processes other than spawning may be implicated in the creation of these otolith growth patterns. Analyses of otolith growth increments for fish of known reproductive status indicated that higher growth during the first primary growth season may allow capelin to reach sexual maturity at a younger age. These results strongly suggest that otolith checks are unreliable indicators of repeat spawning in capelin and may be of questionable utility for identifying past reproductive history of fishes in general. It is recommended that future research to quantify iteroparity in capelin be based on reproductive histology rather than otolith-based methods.

Faster or slower: has growth of eastern Baltic cod changed?

ABSTRACTRecent environmental changes have influenced the ecology and biology of eastern Baltic cod. Declining somatic condition, maturation at smaller size and restricted size distribution of the population suggest that growth rates have decreased between the early 2000s and the 2010s. Extensive age estimation problems have until now precluded testing of this hypothesis. This study presents evidence for a decrease in somatic growth rate of Baltic cod. Temporal patterns of growth, condition and maturation were analysed based on two complementary analyses: length frequency mode progression derived from DATRAS bottom trawl survey data and known-age samples, where size at age was back-calculated from daily otolith growth patterns. In the known-age samples, growth was positively related to somatic condition at capture with maturity dependent differences. Immature individuals had experienced significantly lower growth and were in lower condition at capture than mature individuals. Growth rates in the known-age samples were estimated at 9.5, 7.8 and 5.7 cm per year for age classes 1, 2 and 3 respectively. Growth between age 2 and 3 decreased significantly from 8.8 cm in the 1997 year class to 7.6 cm in the 2010 year class. While the 2001 and 2004 known-age samples were representative for the population, the 2013 sample was biased towards individuals with a higher condition and growth. Complementary length frequency analysis following the length mode of fish from age 2 to age 3 confirmed growth estimates from the early 2000s, while suggesting a 37.5% lower growth in 2013 compared with 2005.

Predators Exacerbate Competitive Interactions and Dominance Hierarchies between Two Coral Reef Fishes.

Predation and competition are critical processes influencing the ecology of organisms, and can play an integral role in shaping coral reef fish communities. This study compared the relative and interacting effects of competition and predation on two competing species of coral reef fish, Pomacentrus amboinensis and P. moluccensis (Pomacentridae), using a multifactorial experiment. Fish were subjected to the sight and smell of a known predator (Pseudochromis fuscus), the presence of the heterospecific competitor (i.e., P. amboinensis vs. P. moluccensis), or a combination of the two for a period of 19 days. The sub-lethal effects of predator/competitor treatments were compared with controls; a combination of otolith microstructure analysis and observations were used to determine otolith growth patterns and behaviour. We predicted that the stress of competition and/or predation would result in strong sub-lethal impacts, and act synergistically on growth and behavioural patterns. We found strong evidence to support this prediction, but only for P. amboinensis, which suffered reductions in growth in both predator and competitor treatments, with the largest reductions occurring when subjected to both predation and competition concurrently. There was strong evidence of asymmetrical competition between the two damselfish species, with P. moluccensis as the dominant competitor, displaying strong aggressive behaviour towards P. amboinensis. Growth reductions for P. amboinensis in predator/competitor treatments appeared to come about primarily due to increases in shelter seeking behaviour, which significantly reduced the foraging rates of individuals compared with controls. These data highlight the importance of predator/competitor synergisms in influencing key behaviours and demographic parameters for juvenile coral reef fishes.

Growth and formation of annual zones in whole otoliths of Greenland halibut, a slow-growing deep-water fish

There is currently no generally agreed and validated method for age estimation of Greenland halibut (Reinhardtius hippoglossoides) from otoliths, and ageing of intermediate sized individuals of this deep-water flatfish is considered particularly uncertain. To estimate otolith growth and annual zone formation in this size range, a large oxytetracycline tagging experiment was undertaken in 2005–08 in the nursery grounds north of the Svalbard Archipelago. By January 2015, 89 of the recaptured fish had both been at large for between 1 and 6 years and had reliable length measurements at release and recapture; 29 of the recaptures were returned with whole otoliths and with a chemical time stamp that allowed identification of otolith growth patterns during time at large. Four age readers interpreted the otoliths without knowing the position of the time stamps. The expected number of zones during time at large was between three and six for 79% of recaptures, and the mean reader bias was only 0.04–0.56 years. Juvenile growth was quantified and the data were analysed in relation to sex and recapture area. This study contributes to a fully validated ageing method for use in stock assessments of this commercially important species.

Quantitative electron microprobe mapping of otoliths suggests elemental incorporation is affected by organic matrices: implications for the interpretation of otolith chemistry

In an effort to understand the mechanism of otolith elemental incorporation, the distribution of strontium (Sr) and sulfur (S) in otoliths of Platycephalus bassensis was investigated in conjunction with otolith growth patterns. Optimisation of electron probe microanalysis (EPMA) quantitative mapping achieved both high spatial resolution (<3µm) and two-dimensional visualisation of the fine scale Sr and S distributions in otoliths of P. bassensis with minimal damage. Electron backscatter diffraction (EBSD) mapping confirmed that grain growth is aligned with the otolith c-axis, with grain orientation independent of both otolith elemental composition and growth patterns. Results showed a linear correlation between Sr and S distribution (R2=0.86), and a clear association with the otolith growth patterns determined by scanning electron microscopy. Further examination by laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) showed that incorporation of Mg and Ba appeared independent of both S distribution and the growth patterns. The results suggest that element incorporation into the otolith is linked to the organic composition in the endolymph during mineralisation, and the organic matrices may assist, in part, the uptake of Sr. Thus, these findings may have significant implications for the interpretation of otolith Sr chemistry.

Lead–radium dating of Pacific cod (Gadus macrocephalus) – validation of the young-fish scenario

Age readers disagree on the age reading interpretation of otolith growth patterns for the Pacific cod (Gadus macrocephalus). One interpretation describes a young-fish scenario with a life span near 10–12 years, whereas another interpretation describes an old-fish scenario at more than 30 years. In this study, lead–radium dating was performed on Pacific cod otoliths to test the validity of the old-fish age reading scenario. Radiometric ages revealed that the young-fish scenario was valid because the actual age of the two oldest adult groups was more than 20 years younger than estimated by the old-fish scenario.

Sclerochronological studies reveal that patterns of otolith growth of adults of two co-occurring species of Platycephalidae are synchronised by water temperature variations

Chronologies are developed from the otolith growth-increment widths of adult rock flathead (Platycephalus laevigatus) and longhead flathead (Leviprora inops) collected from three inter-connected embayments in temperate south-western Australia. Marginal increment trends on otoliths, in combination with the dendrochronological technique of crossdating, provide strong evidence that an opaque zone is formed annually in the otoliths of both species. Increment widths between opaque zones in the otoliths of individuals of P. laevigatus (maximum age 20 years) and L. inops (maximum age 21 years) were synchronised within and between species. The correlation between the two master otolith chronologies, i.e. mean standardised increment width for each year, was highly significant (P < 0.01). The master otolith chronology for each species was positively correlated with mean sea surface temperatures from 1 July to 30 June, which encompassed the austral summer when growth is typically greatest, and with mean monthly sea surface temperature between September and March. Leeuwin Current strength, which influences the biotic characteristics of some marine species on the south coast, has little influence on the pattern of otolith growth, presumably because the inter-connected embayments from which fish were obtained were partially enclosed. On the basis of the above data and the geographical distributions of P. laevigatus and L. inops, it is proposed that, while both species would grow faster with increasing temperature, the temperatures on the south coast are closer to the optimum for the former species.

The use of energy dispersive X-ray spectroscopy to detect strontium marks in fish otoliths

Otolith marking provides a reference point for otolith growth patterns by validating the temporal significance of growth increments. This widespread method is primarily implemented using fluorescent dyes. The incorporation of a trace element that appears naturally in otoliths offers an alternative approach. Diplodus annularis and Serranus scriba otoliths were marked with an intramuscular injection of SrCl 2 diluted in 0.9% sterile saline solution (55 mg Sr ml -1 saline solution), given at a dose of 100 mg Sr kg -1 fish. At 277 to 366 days after marking, the fishes showed little or no mortality and experienced growth in length and weight. All of the otoliths analyzed showed a clear Sr mark detected with backscattered or secondary electron imaging during a scanning electron microsope (SEM) analysis. The mark was confirmed by Sr analysis using an X-ray detector and an energy dispersive spectrometer system with the SEM. The otoliths continued to grow after the mark, and background Sr values in this new growth were much lower than at the mark. This method was feasible and yielded good results. However, the method’s cost may limit its applicability to experimental studies.

Seasonal changes in otolith and somatic growth in age-0 Pacific saury Cololabis saira

We evaluated the seasonal changes in otolith and somatic growth of age-0 Pacific saury Cololabis saira in 223 fish collected between June and November 2002. We calculated the age in days of each individual by measuring otolith growth increments under a scanning electron microscope. The age was correlated with body length and otolith radius. We also observed seasonal changes in the rate of increase in body length and otolith radius and in the pattern of otolith growth. Until August, both body length and otolith radius increased with age. Thereafter, the otolith radius continued to increase, whereas the rate of somatic growth decreased. As a result, the ratio of otolith radius to body length increased. After August, the percentage of otoliths with unreadable increments on their edge increased due to the formation of hyaline zones. Otoliths grew both radially and in thickness until July, but gradually stopped growing in thickness after August. Beginning in October, more than 80% of otoliths only grew radially. After August, the otolith not only continued growing but the morphological growth pattern also changed.

Linking growth to environmental histories in central Baltic young‐of‐the‐year sprat, Sprattus sprattus: an approach based on otolith microstructure analysis and hydrodynamic modelling

AbstractOtolith microstructure analysis and hydrodynamic modelling were combined to study growth patterns in young‐of‐the‐year (YoY) sprat, Sprattus sprattus, which were sampled in October 2002 in the central Baltic Sea. The observed ‘window of survival’, approximated by the distribution of back‐calculated days of first feeding (DFF), was narrow compared to the extended spawning season of sprat in the Baltic Sea (mean± SD = 22 June ± 14.1 days) and indicated that only individuals born in summer survived until October 2002. Within the group of survivors, individuals born later in the season exhibited faster larval, but more rapidly decreasing juvenile growth rates than earlier born conspecifics. Back‐calculated larval growth rates of survivors (0.48–0.69 mm day−1) were notably higher than those previously reported for average larval sprat populations, suggesting that the YoY population was predominantly comprised of individuals which grew faster during the larval stage. Daily mean temperatures, experienced across the entire YoY population, were derived from Lagrangian particle simulations and correlated with (1) detrended otolith growth and (2) back‐calculated, daily somatic growth rates of survivors. The results showed that abrupt changes in ambient temperature can be detected in the seasonal pattern of otolith growth, and that higher temperatures led to significantly faster growth throughout the entire age range of YoY sprat.

Statistical learning applied to computer-assisted fish age and growth estimation from otolith images

Computer-assisted tools need to be developed to help in the accurate and efficient acquisition of fish age and growth data for ecological and assessment issues. Stating fish age and growth analysis as pattern classification issues, the proposed approach relies on a statistical learning strategy. Given otolith images interpreted by an expert, probabilistic kernel-based methods (namely Kernel Logistic Regression) are used to infer interpretation rules. More precisely, two different probabilistic models are introduced: one to infer fish age from otolith images and a second one aiming at evaluating whether or not a given otolith growth pattern is realistic w.r.t. training examples. These probabilistic models provide us with the basis for coping with three different issues: the automated estimation of fish age from otolith images, the estimation of individual otolith growth patterns, and the definition of a confidence measure of otolith interpretations. These computer-assisted ageing tools are validated for a dataset of plaice otoliths.

Growth and morphological development of sagittal otoliths of larval and early juvenile Trachurus japonicus

The daily periodicity of growth increment formation in sagittal otoliths of jack mackerel Trachurus japonicus was validated by marking otoliths with alizarin complexone (ALC). Analysis of otoliths of known‐age juveniles confirmed that the first increment formed on day 3 after hatching, and was associated with first feeding. A total of 198 specimens, ranging from 2·6 to 49·2 mm in body length (notochord length or standard length) and from 7 to 78 days in age, were collected in the East China Sea and Tosa Bay, and used to examine the association between otolith morphological development and ontogenetic development. The relationship between body length (L) and otolith radius (R) was significantly described by the linear function L = 2·65 + 0·0425R(n = 198, r2 = 0·99, P &lt; 0·001), indicating that somatic growth history can be reconstructed from otolith growth patterns. The otolith was primarily spherical in the preflexion larval stage, and became elongated with notochord flexion. The first secondary primordium formed at c. 25 days, during the middle postflexion stage, and was associated with metamorphosis. By c. 42 days the sagittal otolith was adult‐like in morphology, with the primary growth zone enclosed by the marginal growth zone, except in the anterior rostrum area. Thus age, growth and developmental stages were recorded in sagittal otoliths during the larval and early juvenile stages of jack mackerel.

Seasonality in the deep sea and tropics revisited: what can otoliths tell us?

The accepted idea that fish otoliths from supposedly aseasonal environments, such as the deep sea and tropics, do not present seasonal growth increments is questioned and re-evaluated. The main seasonal fluctuation in deep seas is a result of the transfer of organic material from the productive upper layers to the abyssal depths. There is some evidence for seasonal patterns of otolith growth, although the validation of seasonal structures is limited owing to the difficulties inherent in deep-water studies. Tropical regions have an extremely high diversity of aquatic environments but in fact very few are aseasonal, and almost all areas have strong hydrological seasons, mainly annual, interacting with temperature variations. These climatic fluctuations have undoubtedly an effect on otolith growth, therefore leading to a succession of different incremental zones. The lack of previous knowledge on this impact of seasonality is probably a result of the previous low level of exploitation or economic interest of target species, and consequently the absence of age-based assessments. This trend has now changed possibly as a result of the increased exploitation of the resources, and to the greater involvement of international and national fishery management bodies. The number of studies showing apparent or validated seasonal marks has recently increased for these environments.

The selection process from larval to juvenile stages of anchovy (Engraulis encrasicolus) in the Bay of Biscay investigated by Lagrangian simulations and comparative otolith growth

AbstractThe relation between growth and survival was investigated using the otolith growth data collected during repeated larval surveys (May–July) and a juvenile survey (September) undertaken in 1999 on anchovy spawning and nursery grounds in the Bay of Biscay (NE Atlantic). The paper describes the methodology for reading the larval and juvenile otoliths, for reconstructing the correspondence in space and time between juveniles and larvae using Lagrangian simulations, and for comparing the otolith growth rates among the reconstructed sub‐cohorts. Virtual buoys were released weekly on the grid of a three‐dimensional hydrodynamic model and their trajectories were tracked. The origin of an individual was determined by selecting the trajectory beginning on its hatching week and ending at the minimum distance of its sampling location on the sampling date. Larvae and juveniles with the same spatio‐temporal origin were selected and supposed to belong to the same sub‐cohorts. The surviving juveniles showed faster growth rates during their larval period than the pool of larvae they were estimated to originate from, which supports the idea of growth‐selective survival. Alternative interpretations (transport and gear selectivity) are discussed. Variations in otolith growth pattern also suggest a higher juvenile growth over the shelf break than in oceanic waters.

Specific Merluccius otolith growth patterns related to phylogenetics and environmental factors

A comparative morphological study was performed on the otolith growth patterns of 11 species of the genus Merluccius. The otolith growth pattern, based on the radius of the first eight growth increments (GI) from the otolith core, was determined from transverse sections of sagitta otoliths. The structure and periodicity of the GI were identified based on previous knowledge. Two cluster analyses were performed using GI width as a proxy for otolith growth. The first cluster analysis corresponded to the juvenile (immature) period of the fish including the mean width of the first four GI. The second analysis compared the mean width of the next four GI, i.e. those corresponding to mature fish. The results showed an important environmental influence in immature fish; while after maturation, the GI pattern was also related to an endogenous influence depending on the phylogenetic line.

Tracing the life history of red gurnard (Aspitrigla cuculus ) using validated otolith annual rings

Back calculation, marginal increment analysis and modal progression analysis were used to trace growth processes of the red gurnard, Aspitrigla cuculus L., in the Mediterranean Sea. Three false rings appeared regularly on otoliths and were hypothesized to refer to the ontogeny on the basis of the study of the recruitment and reproduction processes of the species. The first two rings were laid down during the first pelagic period and the transformation to the bottom mode of life, respectively. The third ring corresponded to the first spawning at the end of the second year of life. The marginal increment analysis demonstrated that one opaque and one translucent zone is formed each year, the translucent ring corresponding to the period of slow growth in the winter. Temperature and salinity of Mediterranean waters below the thermocline where red gurnard live do not undergo seasonal variations. Therefore, traditional interpretation of the discontinuity patterns on otoliths related to the decrease of water temperature should be rejected for Mediterranean fish distributed on the deep shelf and slope. Discontinuities in otolith structure may be related to seasonal variation in feeding intensity as a consequence of decreases in the benthic mysids biomass and time available to find food due to reduced daylight. Future research should focus on the trophic ecology of the demersal fishes and the seasonal fluctuations of the prey resources during the year in order to assess the role of the food supply with regard to otolith growth patterns in the Mediterranean Sea.

Age estimation, growth and maturity of the European hake (Merluccius merluccius (Linnaeus, 1758)) from Iberian Atlantic waters

Abstract Difficulties in age estimation for hake (Merluccius merluccius) have hampered the assessment of stocks. Here, we describe new, agreed ageing criteria based on the interpretation of the pattern of otolith growth. Improved estimates of von Bertalanffy growth parameters, and new estimates of maturity ogive parameters and length–weight relationships for European hake from Iberian Atlantic waters are presented. The results came from a study carried out during 1996–1997 and provide the first published account of the main life history traits of Southern stock hake. von Bertalanffy growth parameters of males were L∞ = 70cm, K = 0.18 year−1, and t0=−0.97 year, and those of females were L∞ = 89cm, K = 0.13 year−1, and t0 = −1.15 year. Growth of sexes differed from age 3 onwards, with females being on average larger and heavier than males. The estimated total length (L, cm)–total weight (W, g) relationships were W=0.0132135L2.8134246 for males and W=0.0086471L2.942563 for females. Spawning took place from December to May with a peak in February. The mean length and age at first maturity were 32.8 cm at 2.5 years for males and 45 cm at 4.4 years for females. Application of new ageing criteria showed that otolith sections may be used to determine ages up to 5 years in a consistent manner. These results indicate that hake of the Southern stock grow at higher rates and mature earlier than previously considered. Summaries of hake's life history parameters from other marine regions are also presented in order to make information that belongs largely to the grey literature available.

Tracing populations of Atlantic herring (Clupea harengus L.) in the Irish and Celtic Seas using otolith microstructure

Otolith microstructure of juvenile herring was used to distinguish autumn- and winter-spawned fish collected in the Celtic and Irish Seas in 1999 and 2000. Juveniles showed two distinct patterns of larval otolith growth; widely spaced increments (fast growers) and tightly packed increments (slow growers). Fast- and slow-growing fish exhibited a clear bimodal distribution and the two groups were completely distinct at increments 60–70. Otolith increment counts confirmed that the fast-growing fish originated from the winter spawning season and that slow-growing fish were spawned in autumn. This characteristic pattern of otolith growth was used to determine the relative proportions of autumn- and winter-spawned fish at nursery grounds in the Irish and Celtic Seas. Although the proportions in each area varied between years, nursery grounds in the western Irish Sea were generally dominated by winter-spawned fish whereas autumn-spawned fish were mostly at eastern stations. Given the distribution of spawning adults in the region, the vast majority of winter-spawned fish are likely to originate from the Celtic Sea. Larval growth differences between nursery areas suggest that Celtic Sea herring drift into the Irish Sea during the larval phase. There was significant variation in fish size between nursery areas for both autumn- and winter-spawned fish. Juvenile length was greatest in the Celtic Sea, intermediate in the eastern Irish Sea, and lowest in the western Irish Sea. Therefore, larval dispersal of Celtic Sea herring into the Irish Sea produces components in the surviving juvenile population with characteristic growth patterns. This population segregation could potentially impact on subsequent growth, survival and recruitment. 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd.