Comparison of Otolith-Based Back-Calculation Methods to Determine Individual Growth Histories of Larval Striped Bass, Morone saxatilis

1992 ◽  
Vol 49 (7) ◽  
pp. 1439-1454 ◽  
Author(s):  
David H. Secor ◽  
John Mark Dean
Keyword(s):  
Striped Bass ◽  
Somatic Growth ◽  
Morone Saxatilis ◽  
Growth Effect ◽  
Individual Growth ◽  
Quadratic Model ◽  
Calculation Methods ◽  
Otolith Growth ◽  
Experimental Proof ◽  
Back Calculation

In rearing studies on 6- to 22-d-old larval striped bass, Morone saxatilis, we applied several back-calculation methods to known-growth larvae. A growth effect occurred on otolith diameter – standard length relationships, where slower growing larvae had relatively larger otoliths. Otolith growth was less affected by feeding regime than was somatic growth. Due to the conservative nature of otolith growth, proportional based (Biological Intercept Method) and simple linear regression methods linearized somatic growth transitions and did not estimate periods of negative growth. A quadratic regression method which used age as an additional predictor resulted in the accurate back-calculation of size at age in all groups of laboratory-reared larvae. However, when model coefficients were applied to a test population of pond-reared larvae, the quadratic model performed poorly. While differences in relative otolith size between pond- and laboratory-reared larvae could be ascribed to a temperature effect, the inability to apply the model also indicates a problem specific to regression-based methods. Theoretical rationale and experimental proof provided evidence for the inclusion of age in back-calculation models, but parameterization will have to occur for each field application.

An otolith-based back-calculation method to account for time-varying growth rate in rainbow smelt (Osmerus mordax) larvae

1998 ◽  
Vol 55 (12) ◽  
pp. 2662-2671 ◽  
Author(s):  
Pascal Sirois ◽  
Frédéric Lecomte ◽  
Julian J Dodson
Keyword(s):  
Growth Increment ◽  
Growth Effect ◽  
Growth Trajectories ◽  
Osmerus Mordax ◽  
Time Varying ◽  
Relative Importance ◽  
Otolith Growth ◽  
Rainbow Smelt ◽  
Length Increase ◽  
Back Calculation

This study develops a new back-calculation method, based on the larvae of rainbow smelt (Osmerus mordax), that takes into account the variation of growth rate over time. Known-aged larvae were reared in four 60-L microcosms during 49 days in order to obtain a large range of individual growth trajectories. We first validated the daily nature of the otolith increment deposition rate. The proposed time-varying growth (TVG) method weights the contribution of each increment in the length calculation using a growth effect factor. A small growth increment contributes less to the length increase of larvae than its relative importance in total otolith growth. On the other hand, a large growth increment contributes more to the length increase of larvae in comparison with its relative importance in total otolith growth. This method provided significantly better estimates of previous length-at-age than the biological intercept (BI) method at the individual level. In addition, the TVG method tended to provide more accurate estimates of previous length-at-age than the BI method at the population level, but the difference was not significant. The importance of using the TVG method instead of the BI method to back-calculate individual and population growth trajectories increases with the magnitude of the growth effect and the variation in growth rates over time.

How Reliable are Growth Back-Calculations Based on Otoliths?

1990 ◽  
Vol 47 (11) ◽  
pp. 2219-2227 ◽  
Author(s):  
Steven E. Campana
Keyword(s):  
Somatic Growth ◽  
Growth Effect ◽  
Fish Otolith ◽  
Stochastic Error ◽  
Individual Fish ◽  
Back Calculation ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Slow Growing

Growth back-calculations from otoliths assume that the relationship between fish and otolith length is linear through time. The final (or observed) individual fish-otolith ratios are then combined to prepare a fish-otolith regression for the population, upon which the subsequent back-calculations are based. However, recent studies have demonstrated that the fish:otolith size ratio varies systematically with somatic growth rate, resulting in relatively large otoliths in slow-growing fish. Such a growth effect will result in a fitted fish-otolith regression which differs significantly from that of the mean of the individual fish-otolith slopes. Fraser–Lee growth back-calculations made from such a regression consistently underestimate previous lengths at age. The bias may explain the apparent ubiquity of Lee's phenomenon. Back-calculation bias was eliminated through use of an algorithm defining individual fish-otolith trajectories and a biologically determined, rather than a statistically estimated, intercept. Adaptations of the biological intercept back-calculations procedure accurately predicted previous lengths in the presence of both stochastic error and time-varying growth rates. When used to reevaluate some published back-calculations, the biological intercept procedure resulted in more accurate values than those previously estimated, and reduced or eliminated the presence of Lee's phenomenon.

scholarly journals Ocean acidification affects somatic and otolith growth relationship in fish: evidence from an in situ study

2019 ◽  
Vol 15 (2) ◽  
pp. 20180662 ◽  
Author(s):  
Antonio Di Franco ◽  
Antonio Calò ◽  
Khalil Sdiri ◽  
Carlo Cattano ◽  
Marco Milazzo ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Physiological Responses ◽  
Relative Size ◽  
Somatic Growth ◽  
Growth Effect ◽  
Otolith Growth ◽  
Coastal Fish ◽  
Somatic Growth Rate ◽  
In Situ Study

Ocean acidification (OA) may have varied effects on fish eco-physiological responses. Most OA studies have been carried out in laboratory conditions without considering the in situ p CO 2 /pH variability documented for many marine coastal ecosystems. Using a standard otolith ageing technique, we assessed how in situ ocean acidification (ambient, versus end-of-century CO 2 levels) can affect somatic and otolith growth, and their relationship in a coastal fish. Somatic and otolith growth rates of juveniles of the ocellated wrasse Symphodus ocellatus living off a Mediterranean CO 2 seep increased at the high- p CO 2 site. Also, we detected that slower-growing individuals living at ambient p CO 2 levels tend to have larger otoliths at the same somatic length (i.e. higher relative size of otoliths to fish body length) than faster-growing conspecifics living under high p CO 2 conditions, with this being attributable to the so-called ‘growth effect’. Our findings suggest the possibility of contrasting OA effects on fish fitness, with higher somatic growth rate and possibly higher survival associated with smaller relative size of otoliths that could impair fish auditory and vestibular sensitivity.

Somatic Growth Effects on the Otolith–Fish Size Relationship in Young Pond-reared Striped Bass, Morone saxatilis

1989 ◽  
Vol 46 (1) ◽  
pp. 113-121 ◽  
Author(s):  
David H. Secor ◽  
John Mark Dean
Keyword(s):  
Growth Rate ◽  
Striped Bass ◽  
Somatic Growth ◽  
Morone Saxatilis ◽  
Fish Length ◽  
Fish Size ◽  
Somatic Growth Rate ◽  
Size Relationship ◽  
Highly Correlated ◽  
Otolith Size

Somatic growth rate of pond-reared larval and juvenile striped bass, Morone saxatilis, influenced the relationship between otolith size and fish size. Slower growing groups of individuals had larger and heavier otoliths, relative to fish length, than did faster growing groups. Within each growth group, otolith and fish size were highly correlated. Daily increment formation was validated from 10 to 51 d after hatch. Significant interaction occurred between age and fish size effects on otolith size. We propose that otolith growth occurs by two interacting processes. Otoliths grow daily in an incremental manner which is independent of somatic growth. Growth also proceeds continuously within each daily cycle of increment deposition, probably in some proportion to daily somatic growth. Corollaries to the hypotheses are (1) somatic growth rate can influence the otolith–fish size relationship, (2) intraspecific variation in otolith scaling might be used to predict past differences in somatic growth rate, and (3) there is a biological rationale for the use of otolith size and fish size as predictors in age estimation.

Scale analyses to estimate somatic growth in sockeye salmon, Oncorhynchus nerka

1997 ◽  
Vol 54 (3) ◽  
pp. 631-636 ◽  
Author(s):  
M Fukuwaka ◽  
M Kaeriyama
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Somatic Growth ◽  
Individual Growth ◽  
Path Coefficient ◽  
Passive Integrated Transponder ◽  
Linear Path ◽  
Absolute Growth ◽  
Back Calculation ◽  
The Relationship

The relationships between individual growth and scale pattern were examined for juvenile sockeye salmon (Oncorhynchus nerka) marked with passive integrated transponder (PIT) tags to assess the usefulness of scale analyses for estimating somatic growth. The relationship between absolute somatic growth and increment of scale radius was linear. The relationship between increment of scale radius and number of circuli was also linear. Path analysis showed that the number of circuli was directly correlated with absolute growth. A negative path coefficient (-0.200) between absolute growth and number of circuli indicated that circulus spacing was positively correlated with somatic growth. The relationship between circulus spacing and absolute growth was linear (circulus spacing ( µm) = 0.528 times absolute growth (mm) - 9.57). Results indicate that somatic growth affects circulus spacing directly. Circulus spacing was useful for comparing mean growth from the above equation, while back-calculation was useful for estimating individual growth.

Impact of differential energy allocation in Atlantic salmon (Salmo salar) precocious males on otolith–somatic size proportionality: a longitudinal approach

2002 ◽  
Vol 59 (10) ◽  
pp. 1575-1583 ◽  
Author(s):  
Nadia Aubin-Horth ◽  
Julian J Dodson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Somatic Growth ◽  
Energy Allocation ◽  
Time Interval ◽  
Otolith Growth ◽  
Short Term ◽  
Longitudinal Approach ◽  
Back Calculation ◽  
Somatic Size

We studied juvenile Atlantic salmon (Salmo salar) males that become precociously mature or not at age-1+ to test the hypothesis that differential energy allocation affects the relationship between otolith size and fish size and to validate the use of a back-calculation method to estimate size over 30 weeks. We used a longitudinal approach by repeatedly measuring marked fish and obtaining corresponding otolith radius measurements. Differential energy allocation of mature males did not affect the proportionality ratio between otolith and somatic size. Short-term otolith growth varied with short-term somatic growth, but only weakly with temperature. Some correlation coefficients of the covariation of otolith growth estimated over a longer time interval with somatic growth were significantly greater than the short-term estimate. For mature and immature males, back-calculated lengths accurately estimated the observed individual length on practically all occasions. These results indicate that back-calculation can be used to estimate size for Atlantic salmon with different energy allocation patterns. Variable strength of coupling of otolith and somatic growth depending on time interval suggests that these processes are completed on different time scales.

Do Otoliths record changes in somatic growth rate? Conflicting evidence form a laboratory and field study of a temperate Reef Fish, Parika scaber

1992 ◽  
Vol 43 (5) ◽  
pp. 1203 ◽  
Author(s):  
MJ Milicich ◽  
JH Choat
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Field Study ◽  
Reef Fish ◽  
Somatic Growth ◽  
Individual Growth ◽  
Otolith Growth ◽  
Somatic Growth Rate ◽  
Temperate Reef ◽  
Temperate Reef Fish

Otolith increment widths in a temperate reef fish, Parika scaber (Pisces:Monacanthidae), have been shown to vary in different months and to correlate with changes in somatic growth rate. This results in the persistence of a constant otolith-size/fish-size relationship. In the present study, the response of otolith growth to laboratory-induced changes in body growth was determined over a 10-day period in December 1985. Juveniles were subjected to two ranges of temperature (19-21�C and 24-26�C) and three feeding levels (fully fed, partially fed, and starved) of a diet consisting of larvae of Opifex fuscus, an endemic mosquito. Fish were individually tagged to ensure that changes in growth rate and any associated changes in otolith microstructure could be accurately determined for any individual. Fully fed fish grew more slowly during treatment than they did prior to treatment, and starved fish did not grow at all. Partially fed fish exhibited a size-hierarchy effect, with larger fish increasing in body size at the expense of smaller individuals. No temperature effect on growth rate was recorded. In contrast to the results from an associated field study, otoliths of fully fed fish continued to increase at the same daily width despite the induced alteration in growth rate. Thus, otoliths were disproportionately large compared with estimates from the field. However, otoliths of starved fish were not as large as predicted from a continual production of daily rings at a constant width. Daily ring deposition may have ceased at different times during the experiment for the starved fish, depending on body size. Alternatively, deposition may have continued, but at a spacing that was not detectable by light microscopy. We conclude that adequate validation of response of otolith growth to changes in somatic growth is necessary before individual growth histories can be back-calculated. This is true even where strong evidence from the field suggests that back-calculation is possible.

scholarly journals Sex-specific growth effects in protogynous hermaphrodites

2004 ◽  
Vol 61 (3) ◽  
pp. 323-327 ◽  
Author(s):  
Philip L Munday ◽  
Alyson L Hodges ◽  
J Howard Choat ◽  
Nick Gust
Keyword(s):  
Specific Growth ◽  
Somatic Growth ◽  
Early Life History ◽  
Age Effect ◽  
Growth Effect ◽  
Otolith Growth ◽  
Precise Relationship ◽  
Size At Age ◽  
The Relationship ◽  
Slow Growing

We demonstrate sex-specific decoupling of otolith growth and somatic growth in two species of protogynous parrotfishes, Scarus frenatus and Chlorurus sordidus. Otoliths of both species increased in size consistently through life, even though somatic growth rate decreased with age (age effect). Furthermore, in S. frenatus, otoliths from terminal males were smaller than otoliths from females, despite males being larger than females of the same age. This demonstrates the presence of a sex-specific growth effect, where otoliths of fast-growing individuals (males) are smaller than otoliths of slow-growing individuals (females). The sex-specific growth effect for S. frenatus was most pronounced during the early life history, which suggests that only the fastest-growing females change sex to male. A sex-specific growth effect was also evident in C. sordidus, although it was not statistically significant because of greater variation in the otolith size of terminal males of this species. Our results demonstrate that the relationship between otolith and somatic growth can vary dramatically between the sexes. This will make it difficult to back-calculate size at age in protogynous species, or to conduct sex-specific back-calculations in gonochoristic species, unless the precise relationship between otolith and somatic growth is known for each sex.

Emamectin benzoate is a safe and effective anthelmintic against coelomic nematode Philometra rubra in striped bass Morone saxatilis

2020 ◽  
Vol 142 ◽  
pp. 47-53
Author(s):  
K Béland ◽  
G Séguin ◽  
S Lair
Keyword(s):  
Mortality Rate ◽  
Striped Bass ◽  
High Mortality ◽  
Morone Saxatilis ◽  
Treatment Results ◽  
Emamectin Benzoate ◽  
Once Daily ◽  
Fish Hatchery ◽  
Parasitic Burden

An unusually high mortality rate due to verminous (Philometra rubra) coelomitis was documented in wild-hatched striped bass Morone saxatilis raised in a fish hatchery as part of a stock restoration program. To decrease the parasitic burden and therefore potentially minimize mortality, the effectiveness of 2 different anthelmintics was evaluated. Two trials were conducted on wild-collected fingerlings naturally infected by P. rubra. In 2006, 144 yearling fish were randomly assigned to 4 experimental groups: (1) levamisole (Levasol®) at 2 mg l-1 via immersion for 8 h once weekly for 3 wk; (2) levamisole at a dose of 2.5 mg kg-1 biomass via feed once daily for 7 d; (3) emamectin benzoate (Slice®) at a dose of 0.05 mg kg-1 biomass via feed once daily for 7 d; and (4) control. Emamectin successfully eliminated live nematodes in 84.9% of the fish, whereas the administration of levamisole, either via immersion or feed, was not successful in significantly reducing the number of live P. rubra. In 2007, the administration of the same dosage of emamectin to approximately 1000 naturally infected yearling striped bass was associated with a 100% mortality rate of P. rubra in the 30 fish randomly examined 5 wk after the beginning of the treatment. Results of these trials indicate that, at the dosage used, the administration of emamectin at the end of the summer is safe for striped bass yearlings and considerably reduces the prevalence and intensity of the infection by this parasite.

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