Age determination of harbour porpoise, Phocoena phocoena (L.), in the western North Atlantic

1977 ◽  
Vol 55 (1) ◽  
pp. 18-30 ◽  
Author(s):  
D. E. Gaskin ◽  
B. A. Blair
Keyword(s):  
North Atlantic ◽  
Age Determination ◽  
Simple Relationship ◽  
Phocoena Phocoena ◽  
Progressive Reduction ◽  
Opaque Zone ◽  
Translucent Zone ◽  
Males And Females ◽  
Calving Season

Age, based on analysis of dentinal growth layers, was determined in a sample of 121 harbour porpoises, Phocoena phocoena (L.), from western North Atlantic waters. One growth layer, consisting of a thick opaque zone and a relatively thin translucent zone, is deposited each year.Mean thicknesses of opaque and translucent zones in males and females were 347 μm, 114 μm, 432 μm, and 125 μm, respectively. Significant reduction in thicknesses of growth layers with age was found in both sexes, the major contribution in both cases being progressive reduction in thickness of the opaque zones. Translucent-zone thickness decreased with age in males, but significantly increased in thickness in females. Formation of the opaque zone occurs from June through February, and formation of the translucent zone from January to early September. This overlap is attributed to the protracted calving season of this population, and precludes any simple relationship between food supply and zonation, as proposed by others. Age–length relationships based on numbers of dentinal layers were calculated for males and females using regression analysis. Best fits of body length (b) against age (expressed by completed dentinal layers) (d) were obtained from the curvilinear equations: d = [b/(−1.30b + 209.35)] −1 for males, and d = [b/(−0.84b + 156.15)] −1 for females.

scholarly journals Validation of the use of vertebrae and dorsal-fin spines for age determination of spiny dogfish (Squalus acanthias) in the western North Atlantic Ocean

2021 ◽  
Vol 119 (1) ◽  
pp. 41-49
Author(s):  
Kelsey C. James ◽  
Lisa J. Natanson ◽  
Christopher Flight ◽  
Cindy Tribuzio ◽  
John Hoey ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Age Determination ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Dorsal Fin ◽  
Fin Spines

Age, Growth, and Maturity of Bottlenosed Dolphin (Tursiops truncatus) from Northeast Florida

1973 ◽  
Vol 30 (7) ◽  
pp. 1009-1011 ◽  
Author(s):  
D. E. Sergeant ◽  
David K. Caldwell ◽  
Melba C. Caldwell
Keyword(s):  
Tursiops Truncatus ◽  
Accumulation Rate ◽  
Age Determination ◽  
Growth Layer ◽  
Translucent Zone ◽  
Bottlenosed Dolphin ◽  
Males And Females ◽  
Absolute Age

It is confirmed that one growth layer consisting of one opaque and one translucent zone is laid down annually in the dentine of the teeth of bottlenosed dolphin (Tursiops truncatus), allowing absolute age determination, although the seasonal sequence of dentine deposition is not yet clear. On this basis females from northeast Florida were found to mature at about 12 years and males at 13 years, both sexes living to about 25 years of age. Females accumulated up to 14 corpora albicantia in the ovaries, indicating an accumulation rate of about one per annum. Birth occurred at 100-cm length. Males and females matured at about 245- and 235-cm length, respectively, and attained asymptotic lengths of about 270 and 250 cm.

scholarly journals Utility of telomere length measurements for age determination of humpback whales

2014 ◽  
Vol 8 ◽  
Author(s):  
Morten Tange Olsen ◽  
Jooke Robbins ◽  
Martine Bérubé ◽  
Mary Beth Rew ◽  
Per J Palsbøll
Keyword(s):  
Telomere Length ◽  
Quantitative Pcr ◽  
North Atlantic ◽  
Age Determination ◽  
Humpback Whales ◽  
Biological Variability ◽  
Trade Offs ◽  
Length Measurements ◽  
Free Ranging

This study examines the applicability of telomere length measurements by quantitative PCR as a tool for minimally invasive age determination of free-ranging cetaceans. We analysed telomere length in skin samples from 28 North Atlantic humpback whales (Megaptera novaeangliae), ranging from 0 to 26 years of age. The results suggested a significant correlation between telomere length and age in humpback whales. However, telomere length was highly variable among individuals of similar age, suggesting that telomere length measured by quantitative PCR is an imprecise determinant of age in humpback whales. The observed variation in individual telomere length was found to be a function of both experimental and biological variability, with the latter perhaps reflecting patterns of inheritance, resource allocation trade-offs, and stochasticity of the marine environment.

A comparison of age determination techniques for the harbour porpoise, Phocoena phocoena L.

1989 ◽  
Vol 67 (7) ◽  
pp. 1832-1836 ◽  
Author(s):  
Peter Watts ◽  
David E. Gaskin
Keyword(s):  
North Atlantic ◽  
Age Determination ◽  
Harbour Porpoise ◽  
Phocoena Phocoena ◽  
Growth Layer ◽  
Single Cross Section ◽  
Living Bone ◽  
Layer Groups ◽  
Annual Deposition ◽  
Age Estimates

The maximum life-span of the harbour porpoise has been estimated at 13 years (based upon dentinal growth layer groups in the teeth) and at 21 years (based upon growth layers in the periosteal bone of the mandible). We used both techniques to estimate the ages of 120 harbour porpoises from the western North Atlantic, in an attempt to determine the relative reliability of each technique. Dentinal layering was the better predictor of body length. Mandibular layering was highly variable even within a single cross section in most specimens, as a result of both common bifurcation of the layers and destruction of the inner layers by growth and remodelling of the living bone. Furthermore, mandibular layers appear to be deposited at a rate of 2 layers/year, double the deposition rate of dentinal growth layer groups. Age estimates which assume annual deposition of mandibular layers therefore overestimate true age.

Method, Validity, and Variability in the Age Determination of Yellowtail Rockfish (Sebastes flavidus), Using Otoliths

1979 ◽  
Vol 36 (4) ◽  
pp. 377-383 ◽  
Author(s):  
Daniel K. Kimura ◽  
Ruth R. Mandapat ◽  
Sandra L. Oxford
Keyword(s):  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Variance Components ◽  
Variance Component ◽  
Age Determination ◽  
Annular Zone ◽  
Total Variability ◽  
Males And Females ◽  
Age Category

A method using otoliths is presented for the age determination of yellowtail rockfish (Sebastes flavidus). Most of the details of this method are applicable to other species of rockfish. The method is validated in younger fish by documenting growth of the otolith annular zone by month, and by comparison with ages read from scales. Further validation is provided by length-at-age data, which show monotone growth for both males and females. Age reader variability was analyzed for each age category using random effects analysis of variance. This analysis showed that within-reader variances were similar for the two readers. Although there were significant variance components due to between-reader differences for aging some age categories, the contribution of this variance component to total variability was negligible. The standard deviation for an age determination of an otolith was similar for both readers, ranging from about 0.6 at 8 yr to about 1.6 at 19 yr. For both readers, the coefficient of variation was approximately 0.08 at all ages. Key words: Sebastes flavidus, age determination, otoliths

Analysis of Fibronectin and TGF-β1 Immunoexpression to Determination of Wound Vitality in Wistar Rats (Rattus norvegicus)

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Nita Novita ◽  
Hasrayati Agustina ◽  
Bethy S. Hernowo ◽  
Abdul H. Hassan
Keyword(s):  
Rattus Norvegicus ◽  
Wistar Rats ◽  
Age Determination ◽  
Scientific Field ◽  
Wound Age ◽  
Forensic Practice ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Tgf Β1

Wound examination is indispensable in forensic practice. The scientific field of wound age determination has advanced progressively during recent years.The purpose of this study was to determine the differences of fibronectin and TGF-β1 expression in both antemortem and postmortem wounds. This study was an experimental with completely randomized design.  The skin wounds (vital and postmortem) were taken from fourty Wistar rats and divided into 10 groups of rats. Immunohistochemical staining was performed to determine the differences between antemortem and postmortem wounds. The result showed that in 30 minutes after antemortem wound infliction, all of samples showed weak reactivity for fibronectin and TGF-β1 (100%).  In first hour after wound infliction, 3 samples (75%) showed weakly positive and 1 sample (25%) strongly positive for fibronectin and TGF-β1.  In 2 hour after wound infliction, 1 sample (25%) showed weakly positive and 3 sample (75%) strongly positive for fibronectin and TGF-β1.  In 3 and 4 hour after wound infliction, all of samples strongly positive for fibronectin and TGF-β1.  In postmortem wound, all of samples showed negativity for fibronectin and TGF-β1. In conclusion, fibronectin and TGF-β1 may be useful in the determination of wound vitality. Keywords: wound, fibronectin, TGF-β1, vitality

AVALIAÇÃO DO CONHECIMENTO TRADICIONAL DOS PESCADORES DA RDSM APLICADO À IDENTIFICAÇÃO DO SEXO DE PIRARUCUS

2010 ◽  
Vol 5 (2) ◽  
pp. 59-66
Author(s):  
Kelven Lopes ◽  
Helder Lima de Queiroz
Keyword(s):  
Sex Determination ◽  
Traditional Knowledge ◽  
Structured Interviews ◽  
Sustainable Fisheries ◽  
Arapaima Gigas ◽  
Males And Females

This study examined the traditional knowledge of fishermen at Mamirauá Reserve about sex determination of pirarucus, Arapaima gigas Schinz 1822. We evaluated the criteria used for by fishermen in the sector Jarauá at Mamirauá Reserve for this determination, during the fisheries season, from October to November 2004. We analyzed responses of a group of about 15 fishermen collected in structured interviews regarding 109 individual pirarucus, 65 males and 44 females. From this sample, only 64 fish have their sex correctly predicted by the fishermen. Although the traditional knowledge of local fishermen is a key component of the sustainable fisheries of this species, this knowledge is not functional in all ranges and aspects, as in sex distinction. We found that the local fishermen evaluated are not able to recognize the sex of pirarucus, although some criteria applied for this purpose are consistent with their biology. The rates of correct forecasts for recognition of males and females were similar to those obtained by chance, even when the criteria applied were consistent, as the criterion “coloration”, which was significantly consistent for identification of males. Yet the group of fishermen interviewed in this study apparently did not apply this criterion correctly.

Problems associated with the age determination of the oldest pottery yielding cultural layers at the Studenoe 1 site, Transbaikal (southern Siberia)

2021 ◽  
Author(s):  
Masami Izuho ◽  
Fumie Iizuka ◽  
Ian Buvit ◽  
Mikhail V. Konstantinov
Keyword(s):  
Age Determination ◽  
Southern Siberia ◽  
Cultural Layers

scholarly journals Directly ageing the Caribbean spiny lobster, Panulirus argus with validated band counts from gastric mill ossicles

2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada
Keyword(s):  
Spiny Lobster ◽  
Age Determination ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Gastric Mill ◽  
Coefficients Of Variation ◽  
The Caribbean ◽  
First Time ◽  
Reader Experience

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.

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