Age Determination in the White Sucker

1969 ◽  
Vol 26 (3) ◽  
pp. 633-638 ◽  
Author(s):  
R. J. Beamish ◽  
H. H. Harvey

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.


1980 ◽  
Vol 37 (3) ◽  
pp. 534-544 ◽  
Author(s):  
K. H. Mills ◽  
R. J. Beamish

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



1969 ◽  
Vol 26 (5) ◽  
pp. 1199-1203 ◽  
Author(s):  
H. T. Bilton ◽  
D. W. Jenkinson

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%.



1986 ◽  
Vol 43 (8) ◽  
pp. 1588-1594 ◽  
Author(s):  
D. E. Chilton ◽  
H. T. Bilton

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.



2018 ◽  
Vol 82 (3) ◽  
pp. 169
Author(s):  
Ronald Fricke ◽  
Daniel Golani ◽  
Brenda Appelbaum-Golani ◽  
Uwe Zajonz

The scorpionfish Scorpaena decemradiata n. sp. is described from off the coast of Israel in the Gulf of Aqaba, northern Red Sea. The new species is similar to S. porcus Linnaeus, 1758, but is characterized by dorsal fin spines XII, soft dorsal fin rays 10 (the last divided at base); pectoral fin rays 16, uppermost branched pectoral fin ray is the second; lacrimal with 2 spines over maxilla that point at nearly right angle from each other, the posterior pointing ventrally and slightly anteriorly; occipital pit well developed; anteriormost mandibular lateral-line pores small, separated; scales ctenoid; 59-62 scale rows in longitudinal series; scales absent on chest and pectoral fin base; and cirri developed over entire head and body, but no cirri on lower jaw. An updated checklist of the species of the genus Scorpaena Linnaeus, 1758 and a key to the species of the eastern Atlantic, Mediterranean Sea and Red Sea are presented.



Zootaxa ◽  
2004 ◽  
Vol 744 (1) ◽  
pp. 1 ◽  
Author(s):  
ALINE R. ALENCAR ◽  
WILSON J.E.M. COSTA

Two new species of Trichomycterus from isolated small river basins of southeastern Brazil are described: T. pantherinus, new species, from the Rio Santa Maria da Vit ria basin, and T. caudofasciatus, new species, from the Rio Itabapoana basin. Both new species are diagnosed by a combination of morphological features, also occurring in T. alternatus and T. longibarbatus, including number of pectoral-fin rays, odontodes and branchiostegal rays, long filamentous first pectoral-fin ray and wide opercular patch of odontodes. Trichomycterus pantherinus differs from other congeners by possessing a light orangish yellow flank with dark brown to black rounded spots. Trichomycterus caudofasciatus is distinguished from other species of the genus by having four gray bars on the caudal fin.



Zootaxa ◽  
2019 ◽  
Vol 4551 (3) ◽  
pp. 275 ◽  
Author(s):  
KYOJI FUJIWARA ◽  
HIROYUKI MOTOMURA

The clingfishes Lepadichthys frenatus Waite 1904 and Lepadichthys misakius (Tanaka 1908) are both redescribed as valid species, although the latter has previously been regarded as a junior synonym of the former. Lepadichthys frenatus and L. misakius are easily distinguished from their congeners by the following combination of characters: 14–19 dorsal-fin rays; 12–14 anal-fin rays; disc size moderate, its length 15.1–20.8 % of standard length (SL); and dorsal, anal and caudal fins connected by membranes. Lepadichthys misakius can be distinguished from L. frenatus by having 25–28 (modally 26 or 27) pectoral-fin rays [vs. 27–29 (29) in L. frenatus]; the upper end of the gill membrane level with the 5th to 8th (usually 6th) pectoral-fin ray base in lateral view [vs. 6th to 8th (7th)]; the lower 8th to 11th (9th) pectoral-fin ray base attached to the disc base by membrane [vs. 10th to 12th (11th)]; 7–11 (9) gill rakers on each arch [vs. 11–14 (12)]; anterior, posterior and least interorbital widths 9.0–11.8 (mean 10.7), 13.4–16.9 (15.3) and 3.2–8.8 (6.2) % SL, respectively [vs. 8.4–10.2 (9.4), 12.1–14.7 (13.5) and 2.8–5.9 (4.8) % SL, respectively]; and NC2 (nasal canal pore) usually located between the anterior and posterior margins of the posterior nostril (vs. usually located before the posterior nostril anterior margin). Morphological changes with growth of the two species are described in detail and a lectotype designated for L. frenatus. 



Zootaxa ◽  
2005 ◽  
Vol 1043 (1) ◽  
pp. 17 ◽  
Author(s):  
HIROYUKI MOTOMURA ◽  
PETER R. LAST ◽  
GORDON K. YEARSLEY

A new species of small-sized scorpionfish, Scorpaena bulacephala, is described on the basis of seven specimens collected from off Norfolk and Lord Howe Islands, northern Tasman Sea, southwestern Pacific Ocean, at depths of 86–113 m. The new species is closely related to a Hawaiian endemic species, S. colorata. The two species are distinguished from other Indo–Pacific species of Scorpaena by the following combination of characters: exposed cycloid scales covering the anteroventral surface of the body and pectoral-fin base, the lateral surface of the lacrimal without spines, and 17 pectoral-fin rays. The new species differs from S. colorata in having 39–44 longitudinal scales rows and relatively short fin spines and rays, especially short longest pectoral-fin ray (31.5–33.5% of standard length). Morphological changes with growth and sexual dimorphism of the new species are also discussed.



1962 ◽  
Vol 40 (7) ◽  
pp. 1237-1247 ◽  
Author(s):  
C. C. Lindsey

Eggs of 10 pairs of wild ninespine sticklebacks from Hobson's Brook near Cambridge, England, were reared under various controlled temperatures. Temperature for optimum survival to hatching differed between genotypes. Ninety young were examined for counts of vertebrae, spines, and dorsal, anal, and pectoral fin rays. Survivors at high temperature had markedly more vertebrae than survivors at low. Curves of temperature against vertebral count may be V-shaped for each genotype, and optimum survival temperature may produce lowest vertebral count. More basal supports to the dorsal and anal fins and spines were produced at high temperature. Disruptions in one-to-one serial conformity between ray or spine, basal, and vertebral series became progressively commoner at higher rearing temperatures. Parents showed positive correlation between dorsal and anal fin ray counts and number of caudal scutes. Comparisons are made with Gasterosteus aculeatus.



1973 ◽  
Vol 30 (5) ◽  
pp. 607-616 ◽  
Author(s):  
Richard J. Beamish

The use of the scale method to determine age of mature white suckers should be avoided. Sections of pectoral fin rays can provide accurate age determinations for most populations once the position of the first annulus has been identified. The age of immature white suckers can be estimated by both methods. It is suggested that, for identification of the first fin ray annulus and facility in the determination of the age of immature white suckers, both pectoral fins and scales should be sampled in all age and growth studies of this species.White suckers (Catostomus commersoni) from populations examined in this study attained ages of up to 17 years although little or no growth occurred in the latter years. Considerable variation in size at sexual maturity was found throughout the range for this species and, thus, the validity of a subspecies designation for a dwarf white sucker (C. c. utawana) based primarily on size differences should be reexamined.



Zootaxa ◽  
2018 ◽  
Vol 4504 (3) ◽  
pp. 359 ◽  
Author(s):  
LUIS FERNÁNDEZ ◽  
JULIETA ANDREOLI BIZE

Trichomycterus varii new species, is described from a small tributary of the High Andean Plateau Region, Jujuy, Argentina. The new species is distinguished from other species of Trichomycterus by the following characters: the caudal peduncle expanded in the area of procurrent caudal-fin rays, distal tip of pelvic fin not reaching the anus when depressed, the presence of fronto-lachrymal tendon bone without lateral process, the first pectoral-fin ray terminating at the margin of the fin, the distal margin of pectoral-fin rounded, seven pectoral fin rays, 15–19 interopercular odontodes, the supraorbital sensory canal with the presence of pore s3, the infraorbital sensory canal segment with the presence of pores i1 and i3, the laterosensory canal of trunk with three sensory pores, 16 pairs of ribs, 11 precaudal vertebrae, and 25 caudal vertebrae. It closely resembles T. yuska and T. pseudosilvinichthys from northwestern Argentina and western Bolivia, but differs in head canal sensory pattern. 



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