Comparison of Fin-Ray and Scale Age Determinations for Lake Whitefish (Coregonus clupeaformis) and Their Implications for Estimates of Growth and Annual Survival

1980 ◽  
Vol 37 (3) ◽  
pp. 534-544 ◽  
Author(s):  
K. H. Mills ◽  
R. J. Beamish
Keyword(s):  
Age Determination ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Ray Method ◽  
Annual Survival ◽  
Scale Method ◽  
Fin Ray ◽  
Fin Rays ◽  
Slow Growing ◽  
Good Agreement

Fifteen populations of lake whitefish (Coregonus clupeaformis) were sampled to compare the fin-ray and scale aging techniques. There was good agreement between aging methods in fast growing populations, but usually fin-ray ages were larger than scale ages in slow-growing populations. The validity of each aging method was tested by comparing fin-ray and scale ages taken from three populations of whitefish when marked and when recaptured at least 1 yr later. When growth was rapid, recaptured fish formed annular marks on both fin-rays and scales. When growth was slower, annular marks were distinguished on fin-ray sections more often than on scales of recaptured fish. When growth was extremely poor, annular marks on scales of recaptured fish were rarely distinguishable, but still recognizable on the majority of fin-ray sections. When fin-ray ages were consistently larger than scale ages for a given population, fin-ray based estimates of annual survival were higher and growth slower than corresponding scale age based estimates. In general, the fin-ray method was more reliable than the scale method of aging lake whitefish.Key words: lake whitefish, age determination, scales, fin-rays, annual survival, growth

Age Determination in the White Sucker

1969 ◽  
Vol 26 (3) ◽  
pp. 633-638 ◽  
Author(s):  
R. J. Beamish ◽  
H. H. Harvey
Keyword(s):  
Close Agreement ◽  
Age Determination ◽  
White Sucker ◽  
Pectoral Fin ◽  
Ray Method ◽  
Scale Method ◽  
Alternative Method ◽  
Fin Ray ◽  
Fin Rays ◽  
Do So

The purpose of this study was to test the reliability of the scale method for determining the age of white suckers. To do so, an alternative method of "aging" was explored, using sections cut from the first four rays of the pectoral fin. Two hundred and fifty white suckers were tagged, and a piece of one pectoral fin was removed before they were released. A year later, 25 were recaptured, and the rays of the remaining pectoral fin were aged. Of the recaptures, 22 showed clearly the addition of one annulus.Having confirmed the fin-ray method, the age of another 157 suckers was determined by scales and fin rays and compared. The results indicated the scale method was reliable, in this population, until the fish reach an age of 5 years. Beyond 5 years there was not close agreement between scale and fin ages. After 8 years, age as determined by scales was invariably less than from fin rays, and sometimes was in error by as much as 5 years.

New Method for Ageing Chinook Salmon (Onchorhynchus tshawytscha) Using Dorsal Fin Rays, and Evidence if Its Validity

1986 ◽  
Vol 43 (8) ◽  
pp. 1588-1594 ◽  
Author(s):  
D. E. Chilton ◽  
H. T. Bilton
Keyword(s):  
Cross Sections ◽  
Chinook Salmon ◽  
Confidence Level ◽  
Oncorhynchus Tshawytscha ◽  
Significant Proportion ◽  
Ray Method ◽  
Scale Method ◽  
Dorsal Fin ◽  
Fin Ray ◽  
Fin Rays

Age of spawning chinook salmon (Oncorhynchus tshawytscha) was estimated using a combination of thin cross-sections from the dorsal fin rays and scales. The latter were used when freshwater growth could not be interpreted from fin rays. Fish of known age were used when available. Results were compared with ages obtained from scales only. Due to scale resorption a significant proportion of the older fish ages was undetected using only scales. Determinations of freshwater age from fin rays and from scales were in agreement 88.5 ± 8.7 to 92.3 ± 7.2% at the 95% confidence level. Thus, the fin ray method provided virtually the same freshwater age as did the scale method. Also, fin rays provided quite acceptable estimation of ocean age. It is recommended that managers use a combination of scales and fin rays to estimate the total age of spawning chinook salmon.

Growth and Morphometry of Four British Columbia Populations of Pygmy Whitefish (Prosopium coulteri)

1965 ◽  
Vol 22 (5) ◽  
pp. 1229-1259 ◽  
Author(s):  
P. McCart
Keyword(s):  
British Columbia ◽  
Interspecific Competition ◽  
Depth Distribution ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Age At Maturity ◽  
Prosopium Williamsoni ◽  
Slow Growing

A comparison is made of the growth, morphometry, age at maturity, food, and depth distribution of pygmy whitefish (Prosopium coulteri) in four British Columbia lakes. In Tacheeda and Cluculz Lakes where the species is of the usual dwarfed variety, the fish exists sympatrically with two other whitefishes, the mountain whitefish (Prosopium williamsoni) and the lake whitefish (Coregonus clupeaformis). These slow-growing pygmy whitefish differ markedly in morphometry and depth distribution from the "giant" pygmy whitefish of McLeese and Maclure Lakes which live in the absence of other whitefishes. The possibility that differences in the populations might be due to interspecific competition is discussed.

Age Determination of Sockeye (Oncorhynchus nerka) and Chum (O. keta) Salmon from Examination of Pectoral Fin Rays

1969 ◽  
Vol 26 (5) ◽  
pp. 1199-1203 ◽  
Author(s):  
H. T. Bilton ◽  
D. W. Jenkinson
Keyword(s):  
Chum Salmon ◽  
Oncorhynchus Nerka ◽  
Age Determination ◽  
Annual Rings ◽  
Pectoral Fin ◽  
Fin Ray ◽  
Fin Rays ◽  
Ray Methods ◽  
Pectoral Fin Rays

Ages of adult sockeye and chum salmon were estimated from examination of the second anterior pectoral fin ray, and were compared with estimates from their scales or otoliths. For sockeye, only the ocean age could be estimated. Freshwater annual rings could not be distinguished on their fin rays even though they were present on their scales or otoliths. In general, the three methods provided the same estimates of ocean age. Agreement of estimates of ocean age by one to five readers ranged from 78.9 to 98.8%. For chum salmon, the scale and fin ray methods generally provided the same estimates of total age. Agreement of estimates of total age by one or two readers ranged from 73.8 to 99.3%.

First Evidence of Validity of the Fin-Ray Method of Age Determination for Marine Fishes

1983 ◽  
Vol 3 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Alan J. Cass ◽  
Richard J. Beamish
Keyword(s):  
Age Determination ◽  
Marine Fishes ◽  
Ray Method ◽  
Fin Ray

Responses of Lake Whitefish (Coregonus clupeaformis) to Fertilization of Lake 226, the Experimental Lakes Area

1985 ◽  
Vol 42 (1) ◽  
pp. 129-138 ◽  
Author(s):  
K. H. Mills
Keyword(s):  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Experimental Lakes Area ◽  
Annual Survival ◽  
Northwestern Ontario

The responses of an unexploited population of lake whitefish (Coregonus clupeaformis) to fertilization of Lake 226 (L226), the Experimental Lakes Area, northwestern Ontario, were measured for 4 yr (1973–77). A vinyl sea curtain separated the lake into a northeast (NE) basin, which received P, N, and C additions, and a southwest (SW) basin, which received only N and C additions. Lake whitefish in the NE basin grew faster, had higher coefficients of condition, and had greater recruitment and production than those in the SW basin during the 2nd through 4th yr of fertilization. No differences between basins were detected in annual survival for fish [Formula: see text], but survival of age 0 fish was greater in the NE basin. Whitefish production in L226NE averaged twice that in L226SW from the 2nd to the 4th yr of fertilization, though significant variations occurred between years in both the NE and SW populations.

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.

Growth of the Rocky Mountain Whitefish

1941 ◽  
Vol 5b (4) ◽  
pp. 337-343
Author(s):  
T. L. McHugh
Keyword(s):  
Growth Rate ◽  
Age Determination ◽  
Rocky Mountain ◽  
Maximum Length ◽  
Fast Growing ◽  
Scale Method ◽  
Prosopium Williamsoni ◽  
Rates Of Growth ◽  
The Relationship ◽  
Slow Growing

The scale method of age determination has been used to study rates of growth of the Rocky Mountain whitefish, Prosopium williamsoni (Girard), which vary considerably in different localities, and can be correlated to some extent with altitude or temperature. A curve is given showing the relationship between growth of scale and body. Fast-growing individuals tend to maintain their superiority in growth rate throughout their existence. Slow-growing races live longer and eventually reach a maximum length similar to that of fast-growing fish.

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