Effect of Photoperiod on Gonadal Steroid Hormone Levels and Reproductive Cycles of Northern Fur Seals (Callorhinus ursinus)

Mammal Study ◽  
2011 ◽  
Vol 36 (4) ◽  
pp. 223-228
Author(s):  
Naoki Tomita ◽  
Kaoru Kohyama ◽  
Takashi Koido ◽  
Akira Takemura
Keyword(s):  
Steroid Hormone ◽  
Callorhinus Ursinus ◽  
Gonadal Steroid ◽  
Hormone Levels ◽  
Fur Seals ◽  
Northern Fur Seals ◽  
Reproductive Cycles

Estimation of Sexual Maturity Based on Morphometrics of Genital Organs in Male Northern Fur Seals, Callorhinus ursinus

Mammal Study ◽  
2020 ◽  
Vol 46 (1) ◽  
Author(s):  
Yukino Hirakawa ◽  
Takanori Horimoto ◽  
Ippei Suzuki ◽  
Yoko Mitani
Keyword(s):  
Sexual Maturity ◽  
Callorhinus Ursinus ◽  
Fur Seals ◽  
Northern Fur Seals

NATURALLY-OCCURRING LEPTOSPIROSIS IN NORTHERN FUR SEALS (Callorhinus ursinus)

1977 ◽  
Vol 13 (2) ◽  
pp. 144-148 ◽  
Author(s):  
ALVIN W. SMITH ◽  
RICHARD J. BROWN ◽  
DOUGLAS E. SKILLING ◽  
H. L. BRAY ◽  
MARK C. KEYES
Keyword(s):  
Callorhinus Ursinus ◽  
Naturally Occurring ◽  
Fur Seals ◽  
Northern Fur Seals

scholarly journals Effects of Azomite enriched diet on gonadal steroid hormone levels and milt quality indices in Oreochromis mossambicus

2020 ◽  
Vol 17 ◽  
pp. 100341 ◽  
Author(s):  
Habeeb Ashik Ahamed ◽  
Mohamed Jamal Mohamed ◽  
Kantha Deivi Arunachalam ◽  
G.I. Darul Raiyaan ◽  
Mohamed Saiyad Musthafa ◽  
...  
Keyword(s):  
Steroid Hormone ◽  
Oreochromis Mossambicus ◽  
Gonadal Steroid ◽  
Quality Indices ◽  
Hormone Levels

scholarly journals Marked Reduction in Gonadal Steroid Hormone Levels in Rats Treated Neonatally with Monosodium L-Glutamate: Further Evidence for Disruption of Hypothalamic-Pituitary-Gonadal Axis Regulation

1981 ◽  
Vol 33 (5) ◽  
pp. 265-267 ◽  
Author(s):  
Charles B. Nemeroff ◽  
Coral A. Lamartiniere ◽  
George A. Mason ◽  
Robert E. Squibb ◽  
John S. Hong ◽  
...  
Keyword(s):  
Marked Reduction ◽  
Steroid Hormone ◽  
Gonadal Steroid ◽  
Hormone Levels

Estimating the Juvenile Survival Rate of Male Northern Fur Seals (Callorhinus ursinus)

1989 ◽  
Vol 46 (8) ◽  
pp. 1428-1436 ◽  
Author(s):  
Andrew W. Trites
Keyword(s):  
Survival Rate ◽  
Juvenile Survival ◽  
Callorhinus Ursinus ◽  
Strongly Correlated ◽  
Fur Seals ◽  
Commercial Harvest ◽  
Northern Fur Seals ◽  
Back Calculation ◽  
Number Of Males ◽  
Insight Into

Three methods for estimating the survival rate of juvenile northern fur seals (Callorhinus ursinus) are developed from the earlier works of Chapman, Smith and Polacheck and Lander. Each of the methods I propose divides the estimated number of males alive at 2 yr of age by the estimated number of pups born in their year class. The number of surviving juveniles are reconstructed by back calculation using the number of males killed during the commercial harvest and the subsequent counts of bulls. The three methods differ in their assumptions concerning subadult survival and escapement from the harvest, although all produce similar estimates when applied to the St. Paul Island fur seals. These new estimates of juvenile survival (1950–80) are strongly correlated with the ratio of cohort kill to pup production and with estimates from the currently-used Lander procedure. This is because the harvest morality of males is large compared with natural morality. The new methods perform acceptably over a wider class of data than Lander's. Their greatest advantage over current procedures is that they provide a better insight into the reliability of the survival estimates they produce.

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