Effects of Starvation and Delayed Feeding on Growth and Survival of Pacific Cod Gadus macrocephalus Larvae

2019 ◽  
Vol 31 (1) ◽  
pp. 7-15
Author(s):  
Min-Gyu Shin ◽  
So-Gwang Lee ◽  
Hae-Ryeon Jeon ◽  
Jae-Hyeong Joo ◽  
Woo-Seok Gwak
2015 ◽  
Vol 72 (11) ◽  
pp. 1629-1638 ◽  
Author(s):  
Yoji Narimatsu ◽  
Shigeho Kakehi ◽  
Shin-ichi Ito ◽  
Yuji Okazaki ◽  
Ryo Inagawa ◽  
...  

A massive tsunami hit the north Pacific coast of Japan on 11 March 2011. We evaluated the effects of the tsunami on the distribution, growth, and survival of young Pacific cod (Gadus macrocephalus) using data from benthic trawl surveys and otolith microstructure analysis. The distribution of Pacific cod juveniles differed between 2011 and 2008–2010. The 2011 year class was smaller in body size than those in 2008–2010. The majority of 2011 year-class juveniles was captured in deeper areas at a smaller body size, whereas those of previous year classes were primarily distributed in shallower water. The peak hatch of the 2011 year-class juveniles was from early to late February, which was several days later than those of the 2008 and 2010 year classes. The 2011 year class grew at the same rate as those from 2008 and 2010 until the day of the tsunami, but had a lower growth rate during the 30 days after the tsunami, resulting in a decrease in fish size at settlement. Growth of the 2011 year class was also inferior soon after the day of the tsunami in almost all groups divided by the hatching period. Growth of juveniles captured in shallower water following the tsunami in 2011 tended to be slower than that of juveniles captured in deeper water. Our results suggest that the tsunami caused a decrease in growth rates for approximately 30 days and a change in the distribution of juvenile fish relative to prior years. The change in distribution was primarily the result of mortality in shallow water caused by physical damage and (or) subsequent decreased growth. Considering these results and the finding that the recruitment level and the recruits per spawning in the 2011 year class were low, the tsunami may have affected the determination of the recruitment level.


2019 ◽  
Vol 143 (2) ◽  
pp. AB67
Author(s):  
Ichiro Imanishi ◽  
Jumpei Uchiyama ◽  
Takako Matsuda ◽  
Keijiro Mizukami ◽  
Hidekatsu Shimakura ◽  
...  

Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1325 ◽  
Author(s):  
Kai Zhang ◽  
Bafang Li ◽  
Qianru Chen ◽  
Zhaohui Zhang ◽  
Xue Zhao ◽  
...  

Calcium binding peptides from Pacific cod (Gadus macrocephalus) bone have attracted attention due to their potential effects on bone health. In this study, calcium binding peptides (CBP) were prepared from Pacific cod bone by trypsin and neutral protease. Ultraviolet spectra, circular dichroism (CD), and Fourier transform infrared spectroscopy (FTIR) revealed that carboxyl and amino groups in CBP could bind to Ca2+, and form the peptide-calcium complex (CBP-Ca). Single-pass intestinal perfusion (SPIP) experiments indicated that the intestinal calcium absorption was significantly enhanced (p < 0.01) in CBP-Ca treated Wistar rats. The anti-osteoporosis activity of CBP-Ca was investigated in the ovariectomized (OVX) Wistar rat model. The administration of CBP-Ca significantly (p < 0.01) improved the calcium bioavailability, trabecular bone structure, bone biomechanical properties, bone mineral density, and bone mineralization degree. CBP-Ca notably (p < 0.01) increased serum calcium, however, it remarkably (p < 0.01) reduced the levels of osteocalcin (OCN), bone alkaline phosphatase (BALP), tartrate-resistant acid phosphatase isoform 5b (TRAP5b), and C-telopeptide of type I collagen (CTX-1) in serum. Results suggested that the cod bone derived CBP could bind with calcium, improve the intestinal calcium absorption, calcium bioavailability, and serum calcium, then reduce the bone turnover rate, and thus ameliorate osteoporosis.


2009 ◽  
Vol 66 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Kathryn Maja Cunningham ◽  
Michael Francis Canino ◽  
Ingrid Brigette Spies ◽  
Lorenz Hauser

Genetic population structure of Pacific cod, Gadus macrocephalus , was examined across much of its northeastern Pacific range by screening variation at 11 microsatellite DNA loci. Estimates of FST (0.005 ± 0.002) and RST (0.010 ± 0.003) over all samples suggested that effective dispersal is limited among populations. Genetic divergence was highly correlated with geographic distance in an isolation-by-distance (IBD) pattern along the entire coastal continuum in the northeastern Pacific Ocean (~4000 km; r2 = 0.83), extending from Washington State to the Aleutian Islands, and over smaller geographic distances for three locations in Alaska (~1700 km; r2 = 0.56). Slopes of IBD regressions suggested average dispersal distance between birth and reproduction of less than 30 km. Exceptions to this pattern were found in samples taken from fjord environments in the Georgia Basin (the Strait of Georgia (Canada) and Puget Sound (USA)), where populations were differentiated from coastal cod. Our results showed population structure at spatial scales relevant to fisheries management, both caused by limited dispersal along the coast and by sharp barriers to migration isolating smaller stocks in coastal fjord environments.


2020 ◽  
Vol 77 (4) ◽  
pp. 644-650 ◽  
Author(s):  
Benjamin J. Laurel ◽  
Lauren A. Rogers

Pacific cod (Gadus macrocephalus) stocks in the Gulf of Alaska experienced steep, unexpected declines following an unprecedented 3-year marine heatwave (i.e., “warm blob”) from 2014 to 2016. We contend that stock reproductive potential was reduced during this period, evidenced by a combination of new laboratory data demonstrating narrow thermal hatch success (3–6 °C), mechanistic-based models of spawning habitat, and correlations with prerecruit time series. With the exception of single-year El Niño events (1998, 2003), the recent 3-year heatwave (2014–2016) and return to similar conditions in 2019 were potentially the most negative impacts on spawning habitat for Pacific cod in the available time series (1994–2019). Continued warming will likely reduce the duration and spatial extent of Pacific cod spawning in the Gulf of Alaska.


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