scholarly journals Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods

2005 ◽  
Vol 62 (4) ◽  
pp. 655-670 ◽  
Author(s):  
Christoph Stransky ◽  
Sif Gudmundsdóttir ◽  
Thorsteinn Sigurdsson ◽  
Svend Lemvig ◽  
Kjell Nedreaas ◽  
...  

Abstract Age determination of Atlantic redfish (Sebastes spp.) has proven difficult and has led to inconsistent age and growth estimates in the past. Using otoliths of the two major commercial species, golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella), a series of exchange schemes was carried out to assess bias and precision of age readings between four readers and between two preparation methods. Considerable bias between readers and moderate precision were observed for the S. marinus readings, especially for ages >20 years, with coefficients of variation (CV) of 7.7–12.0% and average percent error (APE) of 5.4–8.5%. Agreement between readers increased from 17–28% to 45–61% when allowing deviations of ±1 year, and to 80–92% with ±3 years tolerance. The age of S. marinus determined from broken and burnt otoliths was estimated to be slightly lower than when the age of the same individuals was determined from thin-sectioned otoliths. The bias and precision estimates obtained from the S. mentella material were generally poorer than for S. marinus (CV 8.2–19.1%, APE 5.8–13.5%), but similar to reported values for other long-lived fish species. Better than 50% agreement was only achieved with ±3 years tolerance. Growth rates differed significantly between species, confirming slower growth for S. mentella. For S. marinus, only one reader comparison revealed significantly different growth functions, whereas almost all S. mentella reader pairs showed significant differences in growth curves. Section and break-and-burn readings of S. marinus did not differ significantly. Average ages of around 9–10 years were determined for juvenile S. mentella 24–30 cm long, which were likely to have migrated from East Greenland into the Irminger Sea, based on earlier observations. As some of the error in the age determinations presented could be attributed to interpretation differences between readers, further intercalibration of redfish ageing is urgently needed in order to provide consistent input data for stock assessment.

2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada

Abstract In crustaceans, ecdysis was long believed to result in the loss and replacement of all calcified structures, precluding the use of conventional ageing methods. However, the discovery of bands in the gastric ossicles of several crustaceans with some correlation with age suggests that direct age estimation may be possible. We applied this method to a tropical spiny lobster, Panulirus argus, one of the most iconic and economically valuable species in the Caribbean. The presence of growth bands was investigated using wild lobsters of unknown age and was validated with captive reared lobsters of known age (1.5–10 years) from the Florida Keys, Florida (USA). Bands were consistently identified in ptero- and zygo-cardiac ossicles of the gastric mill and did not appear to be associated with moulting. Validation with known age animals confirms that bands form annually. Counts between independent readers were reproducible with coefficients of variation ranging from 11% to 26% depending on reader experience and the structure used. This study demonstrates, for the first time, that direct age determination of P. argus is possible.


Author(s):  
Susana Garrido ◽  
Susana Ferreira ◽  
Claudia Soares ◽  
Isabel Meneses ◽  
Nuria Baylina ◽  
...  

Abstract Accurate assessment of age and growth of fish is essential to understand population dynamics, namely for age-structured stock assessment and for determining vital rates of fish (e.g. age at sexual maturity) and their relationship with environmental variability. To validate the daily deposition in the otoliths of European sardine (Sardina pilchardus) larvae, these were reared with a range of food densities translating into feeding rates extending from less than required for maintenance to saturated feeding levels. When exogenous feeding began, a high variability in the relationship between number of growth increments (GI) and elapsed days after hatching (dph) was observed, irrespective of the feeding treatment. GI counts using a light microscope were less than one per day for larvae <15 dph (ranging from 0.17–0.43 GI day−1) and similar for larvae reared with different food concentrations. The rate of GI count vs age was significantly higher for larvae older than 15 dph. GI count from 3–30 dph was lower than one per day (0.45–0.75 GI day−1 95% CI) for fed larvae 3–30 dph. Scanning electron microscopy confirmed the daily deposition of GI and revealed some increment widths around 0.2 μm, particularly during the first week post-hatch. Otoliths of wild sardine larvae exhibited narrow GI (<0.5 μm) comparable with reared larvae. This study demonstrates that during the first weeks after hatch the daily increment deposition is underestimated using traditional light microscopy, which must be taken into account in future works determining wild sardine larval growth.


2018 ◽  
Vol 75 (6) ◽  
pp. 2129-2144 ◽  
Author(s):  
Philip R Hollyman ◽  
Simon R N Chenery ◽  
Melanie J Leng ◽  
Vladimir V Laptikhovsky ◽  
Charlotte N Colvin ◽  
...  

Abstract Calculating age and growth rate for the commercially important whelk, Buccinum undatum in the aid of fishery management has historically been undertaken using growth rings on the organic operculum. This is difficult due to their poor readability and confusion between two different sets of growth lines present. Recent work presented the calcium carbonate statolith as an alternative for age determination of B. undatum. Here we compare the use of statoliths and opercula, comparing their readability and creating growth curves for three distinct populations across the United Kingdom. Using these data, we also test the most appropriate growth equation to model this species. Lastly, we use oxygen isotope analysis of the shells to assign accurate ages to several individuals from each site. These data were used to test the accuracy of statolith and operculum ages. Statoliths, whilst more time consuming to process have improved clarity and accuracy compared with the opercula. This improved readability has highlighted that a Gompertz growth function should be used for populations of this species, when in past studies, von Bertalanffy is often used. Statoliths are a viable improvement to opercula when assessing B. undatum in the context of fishery monitoring and management.


2004 ◽  
Vol 61 (2) ◽  
pp. 231-242 ◽  
Author(s):  
Fran Saborido-Rey ◽  
Dolores Garabana ◽  
Santiago Cerviño

Abstract Age determination of redfish is difficult. In this paper, the ages of Sebastes mentella on the Flemish Cap are validated by following year classes from 1991 to 2000. The criteria used for S. mentella are consistent and coherent. The growth of different year classes is described and compared, and density-dependence is demonstrated to influence the growth rate of the strong 1990 year class, growth of that year class being the slowest of those followed. The slow rate of growth prevented that year class from maturing at the anticipated age. Growth is also compared between sexes, of S. mentella, S. marinus, and S. fasciatus, revealing that females grow faster than males. Finally, growth rate is compared among species. S. marinus grows fastest and S. mentella slowest, although the influence of density-dependent growth in S. mentella needs to be taken into consideration.


1982 ◽  
Vol 9 (2) ◽  
pp. 203 ◽  
Author(s):  
WE Poole ◽  
SM Carpenter ◽  
JT Wood

Seven body measurements were taken at regular intervals throughout life from both male and female western grey kangaroos of known birth date. For each sex of three subspecies and for each body measurement a growth curve was fitted, and confidence intervals calculated for determining the age of new animals. As with eastern grey kangaroos, a phase change in the growth curve was apparent at the time when the young vacate the pouch. Join points in the curve for each subspecies of western grey kangaroos were estimated empirically, as three-quarters through the interval between first emergence and final vacation of the pouch by a young animal. The growth curves were represented by a four-parameter non-linear model consisting of two hyperbolas constrained to pass through the common point. Tables presented contrast the ages at which percentile growth values are attained for each subspecies, and also provide examples of the determination of age from body measurements for both males and females, at monthly intervals during their first year. As found for the eastern grey kangaroo, head length proved to be the most reliable criterion, and all measurements of animals older than 2 years were unreliable for age determination.


2009 ◽  
Vol 66 (3) ◽  
pp. 546-560 ◽  
Author(s):  
Romney P. McPhie ◽  
Steven E. Campana

Abstract McPhie, R. P., and Campana, S. E. 2009. Bomb dating and age determination of skates (family Rajidae) off the eastern coast of Canada. – ICES Journal of Marine Science, 66: 546–560. Recent declines in abundance of skates off the eastern coast of Canada have heightened the need for validated age and growth estimates in the region. In all, 502 winter (Leucoraja ocellata), little (Leucoraja erinacea), thorny (Amblyraja radiata), and smooth (Malacoraja senta) skate vertebral centra collected seasonally between 1999 and 2004 were sectioned using a mass processing method, then used to reconstruct growth in each species. Bomb radiocarbon (Δ14C) analysis was used to provide evidence of annual band-pair deposition in thorny skates. Estimates of L∞ from traditional von Bertalanffy growth models (VBGM) ranged from 60.6 cm (little skate) to 89.7 cm (thorny skate), and K estimates from 0.07 (thorny skate) to 0.19 (little skate). A modified two-parameter VBGM (Lmax = 94.1 cm) fitted to winter skate length-at-age data yielded a value of K of 0.15. Maximum observed ages ranged from 12 (little skate) to 19 years in both winter and thorny skates. The year-specific incorporation of Δ14C milled from thorny and winter skate vertebral sections closely resembled shark-derived reference chronology values from the Northwest Atlantic. Pre-bomb Δ14C in a thorny skate collected in 1988 and aged at 23 years appeared to validate age interpretations and suggested that thorny skate reach an absolute age of at least 28 years, the oldest validated age reported for any species of batoid.


Author(s):  
Alexander I. Arkhipkin ◽  
Zhanna N. Shcherbich

The discovery thirty years ago of daily growth increments in squid statoliths and the development of statolith ageing techniques gave new insight into squid age, growth and metabolism. The techniques have shown that the majority of recent coleoid cephalopods live in the ‘fast lane’, growing rapidly and completing their life cycles in a year or less. Surprisingly, these useful approaches to the study of age and growth in squid have not gained much momentum. Only approximately an eighth of more than 300 squid species have had their basic age assessed and described. Two dozen species are subject to continuing arguments about which increments to consider as daily growth increments. This paper outlines major problems encountered during age determination of squid and suggests ways to improve the techniques and make them applicable to a wider spectrum of species.


The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 216-219
Author(s):  
Beatriz E. Arroyo ◽  
Thomas DeCornulier ◽  
Vincent Bretagnolle

Abstract We studied plumage patterns of known-sex nestling and juvenile Short-eared Owls (Asio flammeus) to develop a sexing technique for nestlings in the field. Markings on the secondaries varied according to sex, and differences were apparent from about 10–15 days of age. We also provide aging formulas based on mass for nestlings up to 15 days of age and on wing length for nestlings older than that age. Finally, we evaluate growth parameters according to sex. The asymptotes of body mass, wing length, and tarsus length growth curves were higher in females than males. The inflexion point was attained earlier by males than by females.


Author(s):  
N.A. Anwar ◽  
C.A. Richardson ◽  
R. Seed

The age and growth rate of Modiolus modiolus have been studied from acetate peel replicas of polished and etched shell sections. Age estimates could be reliably obtained from the alternating patterns of light (summer) and dark (winter) growth lines present in the middle nacreous layer of the shell. Growth lines in the inner nacreous layer, however, generally converged to form blocks of nacre such that the identity of individual lines was lost, whilst in the umbones growth lines were often tightly compressed and difficult to resolve. Data obtained from analyses of the internal growth lines in the middle nacreous layer were used to construct growth curves for several subtidal populations using the von Bertalanffy growth equation. The fastest growth rate was recorded for mussels growing epifaunally on the legs of a drilling platform in the North Sea; these mussels achieved a maximum shell length of 110 mm within ten years. The oldest mussel (from Ling Bank in the northern North Sea) was 48 years old and measured 133 mm in length whilst the largest mussel (from Loch Spelve in western Scotland) was 147 mm long and 38 years old. With the exception of the relatively young population (maximum age 10 years) from the drilling platform, most of the benthic populations studied included mussels in excess of 35 years of age. It is clear, therefore, that M. modiolus is a potentially long-lived member of the subtidal benthos.


Author(s):  
Keiichi Tanaka

With the development of scanning electron microscope (SEM) with ultrahigh resolution, SEM became to play an important role in not only cytology but also molecular biology. However, the preparation methods observing tiny specimens with such high resolution SEM are not yet established.Although SEM specimens are usually coated with metals for getting electrical conductivity, it is desirable to avoid the metal coating for high resolution SEM, because the coating seriously affects resolution at this level, unless special coating techniques are used. For avoiding charging effect without metal coating, we previously reported a method in which polished carbon plates were used as substrate. In the case almost all incident electrons penetrate through the specimens and do not accumulate in them, when the specimens are smaller than 10nm. By this technique some biological macromolecules including ribosomes, ferritin, immunoglobulin G were clearly observed.Unfortunately some other molecules such as apoferritin, thyroglobulin and immunoglobulin M were difficult to be observed only by the method, because they had very low contrast and were easily damaged by electron beam.


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