Are Pacific spiny dogfish lying about their age? A comparison of ageing structures for Squalus suckleyi

2018 ◽  
Vol 69 (1) ◽  
pp. 37 ◽  
Author(s):  
Cindy A. Tribuzio ◽  
Mary Elizabeth Matta ◽  
Christopher Gburski ◽  
Calvin Blood ◽  
Walter Bubley ◽  
...  
Keyword(s):  
Age Determination ◽  
Spiny Dogfish ◽  
Suitable Alternative ◽  
Thin Sections ◽  
Full Sample ◽  
Vertebral Centra ◽  
Dorsal Fin ◽  
Sample Set ◽  
Fin Spines

Historically, Pacific spiny dogfish (Squalus suckleyi) have been aged using dorsal fin spines, a method that was validated through bomb radiocarbon analysis and oxytetracycline tagging. However, ages generated using this method generally have poor precision and require estimation of missing growth bands in eroded spines, prompting a search for improved age determination methods. In the present study, spiny dogfish were aged using the historical spine method and a new method involving stained thin sections of vertebral centra. Results of an inter-laboratory exchange demonstrated the need for readers to calibrate ageing criteria with a reference collection before reading structures, a practice that yielded significant improvements in between-reader precision of spine band pair counts. After calibration, the primary readers examined the full sample set. The two structures yielded similar age estimates for younger animals, but centrum estimates were consistently younger than spine estimates after age-10. Although further work is necessary to fully explore potential reasons for the observed bias, such as centrum size and location within the vertebral column, at the present time centra are not a suitable alternative to dorsal fin spines for age determination of Pacific spiny dogfish >10 years of age.

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

scholarly journals Age determination, validation and growth of Grand Bank yellowtail flounder (Limanda ferruginea)

2003 ◽  
Vol 60 (5) ◽  
pp. 1123-1138 ◽  
Author(s):  
Karen S Dwyer ◽  
Stephen J Walsh ◽  
Steven E Campana
Keyword(s):  
Age Determination ◽  
Thin Sections ◽  
Grand Banks ◽  
Yellowtail Flounder ◽  
Limanda Ferruginea ◽  
Conventional View ◽  
Bomb Radiocarbon ◽  
Marginal Increment ◽  
Length Frequency Analysis

Abstract Yellowtail flounder (Limanda ferruginea) (Storer, 1839) on the Grand Bank off Newfoundland were traditionally aged using surface-read whole otoliths. Age determination of otoliths from recaptures of fish tagged in the early 1990s indicated that the traditional ageing technique was underestimating the ages of yellowtail flounder when compared with the time at liberty. Age comparisons between whole and thin-sectioned otoliths showed agreement in age readings up to 7 years; thereafter whole otoliths tended to give much lower ages than those estimated by thin sections. Length–frequency analysis of pelagic and demersal juveniles, captive rearing of juveniles and marginal increment analysis all corroborated age determination based on thin sections. Tag-recaptures and bomb radiocarbon assays validated age interpretations based on thin sections in young and old yellowtail flounder, respectively. Ages were validated up to 25 years for females and 21 years for males. However, because of increased narrowing of annuli in thin-sectioned otoliths from old fish, even thin sections may underestimate the true age of the fish. von Bertalanffy growth curve parameters (combined sexes) were L∞ = 55.6 cm total length, K=0.16 and t0=−0.003. These results challenge the conventional view that yellowtail flounder on the Grand Banks are a relatively fast growing, short-lived species.

Application of Electron Microprobe Age Mapping and Dating of Monazite

2000 ◽  
Vol 6 (S2) ◽  
pp. 406-407
Author(s):  
M. L. Williams ◽  
M. J. Jercinovic
Keyword(s):  
Electron Microprobe ◽  
Age Determination ◽  
Thin Sections ◽  
Geologic Materials ◽  
Mineral Growth ◽  
Ion Probe ◽  
Accessory Phase ◽  
High Concentrations ◽  
Individual Grains

High resolution X-ray mapping and dating of monazite (Th, REE-phosphate) using the electron microprobe is an exceptionally powerful technique for structural, metamorphic, and tectonic analysis in geology. Age determination of geologic materials has been conventionally accomplished by mass spectrometry-based analysis of radioisotopic ratios in minerals from hand-picked mineral separates, careful sampling of individual grains out of petrographic thin sections, or by detailed ion probe analysis. Recently, use of the electron microprobe for dating purposes has been attempted. In principal, the concentrations of Th, U and Pb uniquely define the age if non-radiogenic Pb is either not initially present or can be subtracted from the total Pb. Monazite contains high concentrations of Th and U and does not appear to incorporate significant non-radiogenic Pb during mineral growth. Furthermore, monazite is a ubiquitous accessory phase in many metamorphic and igneous rocks, making it ideal for microprobe dating.

Vertebral rings as a means of age determination in the blue shark (Prionace glauca L.)

1975 ◽  
Vol 55 (3) ◽  
pp. 657-665 ◽  
Author(s):  
J. D. Stevens
Keyword(s):  
Age Determination ◽  
Alternative Methods ◽  
Tooth Replacement ◽  
Blue Shark ◽  
Prionace Glauca ◽  
Vertebral Centra ◽  
Rate Of Growth ◽  
Elasmobranch Fishes

Elasmobranch fishes cannot at present be aged by scale or otolith readings as can certain teleosts. Consequently comparatively little is known about their age or rate of growth, particularly in the case of larger sharks. Alternative methods of age determination within this group have utilized tagging data (Bonham et al., 1949; Holden, 1972); size frequencies (Olsen, 1954; Aasen, 1966); the spine of Squalus sp. (Kaganovskaia, 1933; Holden & Meadows, 1962); tooth-replacement rates (Moss, 1967, 1972) and vertebral rings. These rings on the vertebral centra, resulting from variations in calcification, have also been used in the age determination of teleosts. In the scombroids there is often considerable variation in results even between authors working on the same species, mainly due to difficulty in interpreting the rings and deciding whether they are true year marks (Aikawa & Katô, 1938; Partlo, 1955; Otsu & Uchida, 1959; Hui-chong, Nose & Hiyama, 1965).

Age Determination of an Elasmobranch (Squalus acanthias) by X-ray Spectrometry

1977 ◽  
Vol 34 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Barry C. Jones ◽  
Glen H. Geen
Keyword(s):  
Age Determination ◽  
Element Composition ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Strait Of Georgia ◽  
X Ray ◽  
Spectrometric Technique

Ages of spiny dogfish (Squalus acanthias) in the Strait of Georgia, B.C., have been estimated by an X-ray spectrometric technique which involves measuring variations in the element composition within vertebrae.

Reassessment of spiny dogfish Squalus acanthias age and growth using vertebrae and dorsal-fin spines

2011 ◽  
Vol 80 (5) ◽  
pp. 1300-1319 ◽  
Author(s):  
W. J. Bubley ◽  
J. Kneebone ◽  
J. A. Sulikowski ◽  
P. C. W. Tsang
Keyword(s):  
Squalus Acanthias ◽  
Age And Growth ◽  
Spiny Dogfish ◽  
Dorsal Fin ◽  
Fin Spines

Age Determination of Lingcod (Ophiodon elongatus) Using Dorsal Fin Rays and Scales

1977 ◽  
Vol 34 (9) ◽  
pp. 1305-1313 ◽  
Author(s):  
Richard J. Beamish ◽  
D. Chilton
Keyword(s):  
Key Words ◽  
Cross Sections ◽  
Age Determination ◽  
Fish Length ◽  
Dorsal Fin ◽  
Ophiodon Elongatus ◽  
Fin Ray ◽  
Fin Rays ◽  
Key Words Age

Cross sections of the 4th–8th fin rays from the second dorsal fin provided reliable ages of lingcod (Ophiodon elongatus), although there was some difficulty interpreting the ages of 1- and 2-yr-old fish. Length was an acceptable indicator of age 1- and 2-yr-old fish. After a scale age of 5 or 6 yr, the scale annulus became difficult to identify. After age 7 or about 75–85 cm, fin-ray ages were older than scale ages. Some of the oldest fish averaged 8 yr older by the fin-ray method.Mature females attained much larger mean sizes than males of similar age, and there was considerable variation in size of similar-aged older fish. Key words: Age determination, fin rays, scales, Ophiodon elongatus, ageing errors.

scholarly journals Bomb dating and age determination of skates (family Rajidae) off the eastern coast of Canada

2009 ◽  
Vol 66 (3) ◽  
pp. 546-560 ◽  
Author(s):  
Romney P. McPhie ◽  
Steven E. Campana
Keyword(s):  
Growth Models ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Vertebral Centra ◽  
A Value ◽  
Bomb Radiocarbon ◽  
Absolute Age ◽  
Two Parameter

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.

Determination of the phase structure of polymerblends by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 492-493
Author(s):  
Dr. G. Kaemof
Keyword(s):  
Screw Extruder ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Single Screw Extruder ◽  
Transmission Electron ◽  
The Matrix ◽  
Twin Screw ◽  
Special Case ◽  
Microscopic Investigations

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.

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

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