Responses of meristic characters in chum salmon (Oncorhynchus keta) to temperature changes during development

1989 ◽  
Vol 67 (3) ◽  
pp. 596-600 ◽  
Author(s):  
Clyde B. Murray ◽  
Terry D. Beacham
Keyword(s):  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Meristic Characters ◽  
Gill Rakers ◽  
Temperature Changes ◽  
Chum Salmon Oncorhynchus Keta ◽  
Fin Ray ◽  
Fin Rays ◽  
Eye Pigmentation ◽  
Pelvic Fin

Variability in the number of dorsal, anal, caudal, pectoral, and pelvic fin rays, vertebrae, and gill rakers was examined in four populations of chum salmon (Oncorhynchus keta) transferred from 8 to 2 °C at various stages of embryonic development. Late transfers at complete eye pigmentation produced more gill rakers than transfers earlier in development. Transfers at completion of epiboly and initial eye pigmentation produced fewer vertebrae than earlier or later transfers. Stage of transfer had no significant effect on fin ray counts. Vertebral responses differed among families. Genotype–environment interactions produce meristic phenotypes that are presently difficult to predict.

The effect of spawning time and incubation temperature on meristic variation in chum salmon (Oncorhynchus keta)

1986 ◽  
Vol 64 (1) ◽  
pp. 45-48 ◽  
Author(s):  
T. D. Beacham ◽  
C. B. Murray
Keyword(s):  
Chum Salmon ◽  
Incubation Temperature ◽  
Oncorhynchus Keta ◽  
Gill Rakers ◽  
Dorsal Fin ◽  
Chum Salmon Oncorhynchus Keta ◽  
Fin Rays ◽  
Spawning Stock ◽  
Spawning Time ◽  
Pelvic Fin

Variability in the number of dorsal, anal, caudal, pectoral, and pelvic fin rays, vertebrae, and gill rakers of early and late spawning stocks of Chehalis River chum salmon (Oncorhynchus keta) incubated under controlled water temperatures of 4, 8, and 12 °C was examined. The early spawning stock had fewer dorsal fin rays, more anal fin rays, fewer pectoral and pelvic fin rays, and fewer gill rakers than did the late spawning stock. Chum salmon originally incubated at 4 °C had the lowest number of dorsal fin rays, but the highest number of vertebrae and gill rakers. Chum salmon originally incubated at 8 °C had the highest number of anal fin rays, and those incubated at 12 °C had the highest number of pectoral fin rays. Meristic phenotypes had both a genetic and an environmental component.

A genetic analysis of meristic and morphometric variation in chum salmon (Oncorhynchus keta) at three different temperatures

1990 ◽  
Vol 68 (2) ◽  
pp. 225-229 ◽  
Author(s):  
Terry D. Beacham
Keyword(s):  
Chum Salmon ◽  
Fork Length ◽  
Oncorhynchus Keta ◽  
Meristic Characters ◽  
Morphometric Variation ◽  
Morphometric Characters ◽  
Chum Salmon Oncorhynchus Keta ◽  
Different Temperatures ◽  
Character Variation ◽  
Temperature Interactions

A nested mating design was used in which 10 males were mated with 20 female chum salmon (Oncorhynchus keta), and individuals from each of the 20 families were maintained at 6, 10, and 14 °C from egg fertilization until juveniles reached a fork length of about 61 mm. Variation in 11 morphometric and 3 meristic characters was evaluated. Rearing temperature had a marked effect on juvenile morphometric variation, enough to assign correctly 91% of the juveniles reared at 14 °C, 90% of the juveniles reared at 10 °C, and 95% of the juveniles reared at 6 °C. The addition of meristic character variation increased the classification accuracy to 97, 92, and 96%, respectively. As rearing temperatures increased, the observed levels of fluctuating asymmetry for the three meristic characters increased. Morphometric characters tended to have lower heritabilities than did meristic characters. Genotype–temperature interactions generally accounted for between 10 and 30% of observed phenotypic variation for most characters.

Adaptive Variation in Body Size, Age, Morphology, Egg Size, and Developmental Biology of Chum Salmon (Oncorhynchus keta) in British Columbia

1987 ◽  
Vol 44 (2) ◽  
pp. 244-261 ◽  
Author(s):  
T. D. Beacham ◽  
C. B. Murray
Keyword(s):  
Developmental Biology ◽  
British Columbia ◽  
Chum Salmon ◽  
Incubation Temperature ◽  
Survival Rates ◽  
Lower Number ◽  
Small Rivers ◽  
Oncorhynchus Keta ◽  
Meristic Characters ◽  
Chum Salmon Oncorhynchus Keta

Chum salmon (Oncorhynchus keta) stocks in British Columbia spawning from August through January and in rivers of different size were surveyed for variation in sex ratios, age composition, meristic characters, morphology, and developmental biology. Males were more abundant than females at the younger (2 and 3 yr of age) and older (5 and 6 yr of age) age-classes. Males had larger heads, thicker caudal peduncles, and larger dorsal fins than did females, but females had larger anal fins than did males. Stocks from large rivers had larger heads, thicker caudal peduncles, and larger fins than did those from small rivers. Chum salmon in an area characterized by a lower number of gillrakers also had a lower number of branchiostegal rays. At the same incubation temperature, alevin hatching time was similar for all stocks examined except those from the Queen Charlotte Islands, which was later than the other stocks. Early-spawning stocks had older fish, larger eggs, and later times of fry emergence than did late-spawning stocks. Late-spawning stocks had higher survival rates of embryos at 4 °C than did early-spawning ones. Stocks had different trends in alevin and fry length and weight with respect to incubation temperature. Northern stocks were more efficient than southern stocks at converting egg yolk to fry body weight at low incubation temperatures (4 °C). Selection has produced stocks adapted to the various environments that they encounter in their natal streams, allowing chum salmon to exploit a wide variety of spawning habitats in British Columbia.

scholarly journals A new species of Pimelodus La Cépède, 1803 (Siluriformes: Pimelodidae) from rio Ribeira de Iguape basin, Brazil

2011 ◽  
Vol 9 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Frank Raynner V Ribeiro ◽  
Carlos Alberto S. de Lucena ◽  
Osvaldo T Oyakawa
Keyword(s):  
New Species ◽  
Dorsal Surface ◽  
Branchial Arch ◽  
The Other ◽  
Gill Rakers ◽  
Caudal Fin ◽  
Fin Rays ◽  
A New Species ◽  
Pelvic Fin

Pimelodus multicratifer, a new species, is described from the rio Ribeira de Iguape basin. The new species differs from the other Pimelodus species by the following features: 26 to 30 gill rakers on the first branchial arch; a combination of three to six rows of dark spots regularly or irregularly scattered on the flanks and several small dark spots irregularly scattered on the dorsal surface of head, supraoccipital process, and sometimes on the dorsal and caudal fins; striated lips; maxillary barbels reaching between posterior tip of the pelvic-fin rays and posterior tip of the middle caudal-fin rays.

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