Otolith Microstructore of Larval Herring (Clupea harengus): Image or Reality?

1987 ◽  
Vol 44 (11) ◽  
pp. 1922-1929 ◽  
Author(s):  
Steven E. Campana ◽  
Jacques A. Gagné ◽  
Jean Munro
Keyword(s):  
Systematic Difference ◽  
Clupea Harengus ◽  
Sensitive Species ◽  
Daily Growth ◽  
Growth Increments ◽  
Pelagic Larvae ◽  
Rate Of Increase ◽  
Increment Formation ◽  
Slow Growing ◽  
Mortality Estimates

When assessed with light microscopy, daily increment formation did not appear to occur in the otoliths of known-age larval herring (Clupea harengus). Increment counts underestimated age in all larvae. The age-increment discrepancy increased curvilinearly with age and appeared to stabilize after 50–60 d. Both the magnitude and rate of increase of the discrepancy were consistent with a hypothesis of resolution-limited increment visibility; models of daily otolith growth indicated that discrete daily growth increments would not be resolvable with a light microscope for the first 15–20 d after hatch. The hypothesis was also consistent with the observed effects of otolith polishing, a systematic difference in increment counts between different-sized sagittae in the same larvae, and other published reports of apparent nondaily increment formation in slow-growing pelagic larvae. Previous reports of growth rate limited increment formation appear to provide an empirical description of the same phenomenon. Otolith-based age, growth and mortality estimates can be expected to be biased if resolution effects are ignored. However, various procedures are available for the identification of potentially sensitive species and samples.

scholarly journals Age determination in merobenthic octopuses using stylet increment analysis: assessing future challenges using Macroctopus maorum as a model

2011 ◽  
Vol 68 (10) ◽  
pp. 2059-2063 ◽  
Author(s):  
Zoë A. Doubleday ◽  
Jimmy White ◽  
Gretta T. Pecl ◽  
Jayson M. Semmens
Keyword(s):  
Body Weight ◽  
Life History ◽  
Early Life ◽  
Age Determination ◽  
Early Life History ◽  
Daily Growth ◽  
Life History Stages ◽  
Growth Increments ◽  
Increment Formation ◽  
Future Challenges

Abstract Doubleday, Z. A., White, J., Pecl, G. T., and Semmens, J. M. 2011. Age determination in merobenthic octopuses using stylet increment analysis: assessing future challenges using Macroctopus maorum as a model. – ICES Journal of Marine Science, 68: 2059–2063. Stylet increment analysis (SIA) is a method recently developed to age octopuses; it involves the enumeration of daily growth increments within stylets (an internal shell). To examine the potential of SIA in a merobenthic octopus species, SIA was applied to Macroctopus maorum collected from southeast Australia and New Zealand (n = 147). The stylets had clear concentric growth increments and a core-like region. However, low increment counts (≤224 d) produced non-feasibly high (≤21.7% body weight per day) instantaneous growth rates, based on the assumption that increment number relates to age (d). In the light of these results, the issues surrounding the application of SIA to merobenthic octopuses is discussed, particularly in relation to the lack of understanding in regard to stylet development in the early life history stages and the importance of validating age at first increment formation.

Spatial Variability of Recent Otolith Growth and RNA Indices in Pelagic Juvenile Diaphus kapalae (Myctophidae): an Effect of Flow Disturbance near an Island?

1996 ◽  
Vol 47 (2) ◽  
pp. 273 ◽  
Author(s):  
IM Suthers
Keyword(s):  
Dry Weight ◽  
Otolith Growth ◽  
Flow Disturbance ◽  
Daily Growth ◽  
Growth Increments ◽  
Recent Growth ◽  
Significant Difference ◽  
Increment Formation ◽  
Marginal Increment ◽  
Pelagic Juvenile

In February 1993, the pelagic juvenile myctophid Diaphus kapalae was sampled with a neuston net in the southern Coral Sea in a region of flow disturbance north of Cato Reef, and to the east in the free stream (northerly flow at 30 cm s-1). There was no significant difference in the size (11-16 mm SL) or age (45-74 days after hatching) between the two regions. Recent growth indices derived from the width of the peripheral daily growth increments (~10 μm each) revealed enhanced otolith growth 38 km downstream and up to 4 days before capture. No significant difference was found for times longer than a week before capture, consistent with fluctuation of the wake indicated from current-meter data. Daily increment formation was confirmed by marginal increment analysis. Recent otolith growth was correlated with the RNA content adjusted by dry weight, which also revealed significantly higher condition in the wake region. Recent growth was correlated with microzooplankton biomass, recorded with an optical plankton counter.

Growing of replacement young cattle in ООО «PskovAgroInvest»

2022 ◽  
Vol 354 (11-12) ◽  
pp. 40-42
Author(s):  
N. A. Shcherbakova ◽  
A. Yu. Kozlovskaya
Keyword(s):  
Dairy Cattle ◽  
Old Age ◽  
Live Weight ◽  
Cattle Breeding ◽  
Group Approach ◽  
Daily Growth ◽  
Young Stock ◽  
Rate Of Increase ◽  
Dairy Cattle Breeding ◽  
Young Cattle

ООО «PskovAgroInvest» pays great attention to the rearing of replacement young animals. The rate of increase in the intensity of raising heifers on the farm meets the standards and requirements of pedigree dairy cattle breeding. The farm uses stage-bystage rearing of replacement young stock, taking into account its age. A group approach to rearing young animals. Replacement heifers use natural and cultivated pastures in the summer. In recent years, the age of replacement heifers at the first insemination has noticeably decreased and approached the norm. At the same time, the live weight of animals at the first insemination increased, which in 2020 amounted to 460 kg, which opens up prospects for a further decrease in the age of the first insemination. This became possible due to an increase in the average daily growth in cultivation, which regularly increases every year and amounts to 756 g in 2020, which is 98 g, or 14.9%, more than in 2016. From table 2 it follows that in recent years, at all age periods, replacement heifers had a live weight exceeding the breed standard, which is 250 kg at 10-month-old, 290 kg at 12-month-old and 390 kg at 18-month-old age. At the same time, an increase in the average live weight of the replacement livestock is observed every year. So, in 2020, the value of the indicator was 278 kg at the age of 10 months, 331 kg at the age of 12 months, 463 kg at the age of 18 months, which is 16 kg, 54 kg and 75 kg, or 6.1%, 19, 5% and 19.3%, more than in 2016, respectively. Thus, the analyzed period allows us to conclude about the effectiveness of zootechnical work to improve the rearing of replacement heifers on the farm, but it must be continued in order to reduce the age of first insemination to 15–17 months with the optimal live weight of the livestock.

Analyses of field moult data: prediction of intermoult period and assessment of seasonal growth in Antarctic krill, Euphausia superba Dana

1989 ◽  
Vol 1 (4) ◽  
pp. 301-306 ◽  
Author(s):  
Friedrich Buchholz ◽  
David J. Morris ◽  
Jonathan L. Watkins
Keyword(s):  
Food Availability ◽  
Antarctic Krill ◽  
Marked Effect ◽  
Laboratory Data ◽  
Euphausia Superba ◽  
Simple Relationship ◽  
Daily Growth ◽  
Growth Increments ◽  
Data Prediction ◽  
Field Samples

A technique for moult staging Antarctic krill (Euphausia superba Dana) was used in the analysis of field samples to predict intermoult periods and hence assess growth and the effects of seasonal changes in food availability. The proportion of moulting krill was used, in conjunction with laboratory data on the duration of this phase, to predict the moulting frequency (intermoult period, IMP). The moulting frequency was then combined with appropriate daily growth increments from laboratory study to assess overall growth in the krill sampled. The effects of seasonal fluctuations in food availability on moulting frequency were examined for samples taken at five different locations and times of year. Moulting rate was not linearly related to the availability of phytoplankton, although it is likely that this factor has a marked effect. Similarly, although temperature affects IMP, the data indicate that this is not a simple relationship either. These preliminary data indicate the value of utilizing this technique in the analysis of field samples of Antarctic krill.

Effect of trawling on juvenile red snapper (Lutjanus campechanus) habitat selection and life history parameters

2008 ◽  
Vol 65 (11) ◽  
pp. 2399-2411 ◽  
Author(s):  
R. J. David Wells ◽  
James H. Cowan, ◽  
William F. Patterson ◽  
Carl J. Walters
Keyword(s):  
Life History ◽  
Red Snapper ◽  
Lutjanus Campechanus ◽  
Daily Growth ◽  
Life History Parameters ◽  
Probability Of Survival ◽  
Natural Reef ◽  
Mortality Estimates ◽  
Lower Production ◽  
Ontogenetic Habitat Shifts

This study documents ontogenetic habitat shifts of red snapper ( Lutjanus campechanus ) and highlights possible impacts of shrimp trawling on age-0 fish life history parameters on the northern Gulf of Mexico (GOM) continental shelf. Red snapper were collected quarterly during 2004 and 2005 over sand, low-relief shell rubble, high-relief shell rubble, and natural high-relief reef habitats within a de facto nontrawl area and in similar habitats on the open shelf where commercial shrimp trawling occurred. Age-0 red snapper were most dense over sand and low-relief shell rubble habitats and moved to higher-relief shell rubble and natural reef habitats by age-1. Habitat-specific daily growth rates of age-0 fish were highest over sand (range 0.65–1.03 mm·day–1). Densities of age-0 red snapper were highest over trawled sand, but higher over nontrawled shell rubble by 6 months of age (age-0.5+). Red snapper collected over sand and low-relief shell rubble areas exposed to trawling had truncated size distributions, higher mortality estimates, and lower production potential (the latter evaluated with G–Z and P–B ratios) compared with fish over nontrawled areas of similar habitat. Results suggest that juvenile red snapper residing over nontrawled areas may have a higher probability of survival than fish in areas exposed to commercial shrimp trawling.

Influence of biomass and ocean climate on the growth of Pacific herring (Clupea pallasi) from the southwest coast of Vancouver Island

1997 ◽  
Vol 54 (12) ◽  
pp. 2782-2788 ◽  
Author(s):  
R W Tanasichuk
Keyword(s):  
Growth Rates ◽  
Growing Season ◽  
Vancouver Island ◽  
Pacific Herring ◽  
Daily Growth ◽  
Sea Temperature ◽  
Clupea Pallasi ◽  
Southwest Coast ◽  
Growth Increments ◽  
Adult Growth

I examined the growth of Pacific herring (Clupea pallasi) from the southwest coast of Vancouver Island using data for over 83 000 fish seined between 1975 and 1996. Size-at-age (length, total mass) of recruits (age 3) was negatively related to parental biomass. Length was also negatively related to sea temperature over the first growing season and positively related to salinity later in the third growing season. Prerecruit effects explained variations in mass and length for adult herring ages 4 and 5, respectively. Growth of adults was described as growth increments (growth rates). Seasonal growth in length for adults was assumed to be a linear function of time, and growth in mass an exponential function. Daily growth rates for length were negatively related to initial length. Instantaneous daily growth rates in mass were a negative function of initial mass, adult biomass, and sea temperature in August. Interannual variations in condition suggest that adults grow differently in mass than they do in length. I suggest that length is not synonymous with mass as a measure of adult growth. Consequently, it provides little, if any, information on surplus energy accumulation by adults and therefore adult fish contribution to stock productivity.

Estimating the ages of successional stands of tropical trees from growth increments

1997 ◽  
Vol 13 (6) ◽  
pp. 833-856 ◽  
Author(s):  
John Terborgh ◽  
Cesar Flores N. ◽  
Peter Mueller ◽  
Lisa Davenport
Keyword(s):  
Tropical Forests ◽  
Primary Succession ◽  
Tropical Trees ◽  
Applied Science ◽  
Point Bar ◽  
Growth Increments ◽  
Loess Regression ◽  
Successional Species ◽  
Time Required ◽  
Slow Growing

ABSTRACTInability to age tropical trees has imposed major limitations on the basic and applied science of tropical forests. Here advantage was taken of even-aged stands present in successional chronosequences found on Amazonian Whitewater river meanders to simplify the assumptions needed to estimate tree ages from growth measurements. Growth increments of eight common early successional species were measured in 21 0.5-ha plots evenly distributed over chronosequences from the earliest post-pioneer stage to mature Ficus-Cedrela stands representing approximately the mid-point of primary succession. Increment measurements, based on 4 or 5 y of growth, were arrayed in scatter diagrams against the midpoints of the growth intervals. A loess regression of the points, weighted for the higher mortality of slow-growing individuals, was then conducted to generate a ‘best estimate lifetime growth trajectory’ (BELGT) of a ‘typical’ individual surviving to maturity. The BELGT curves were integrated to generate a set of derived curves describing the time required by a ‘typical’ surviving individual to attain any given size up to the maximum for the species. Predictions of the ages of particular stands were derived from these latter curves and found to agree within 3 to 20% of ages independently estimated from the rate of point bar accretion.

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