Net-chasing training improves the behavioral characteristics of hatchery-reared red sea bream (Pagrus major) juveniles

2018 ◽  
Vol 75 (6) ◽  
pp. 861-867 ◽  
Author(s):  
Kohji Takahashi ◽  
Reiji Masuda
Keyword(s):  
Red Sea ◽  
Stock Enhancement ◽  
Sea Bream ◽  
Control Fish ◽  
Control Group ◽  
Behavioral Characteristics ◽  
Red Sea Bream ◽  
Pagrus Major ◽  
Exposure Test ◽  
Start Area

The low return rate of fish released for stock enhancement has often been attributed to hatchery-reared fish having inferior behavioral characteristics. We tried to improve the behavioral characteristic of red sea bream (Pagrus major) juveniles by using a net-chasing treatment. The fish were provided with 2 min of net chasing twice daily for 3 weeks, following which their behavioral characteristics (emergence from a start area, avoidance response to novel stimulus, and foraging following transfer between tanks) were individually tested and compared with a control group. A predator exposure test was then conducted using marbled rockfish (Sebastiscus marmoratus). Net-chased fish exhibited a shorter latency to emergence, a higher avoidance rate, and an earlier foraging time than the control fish, indicating that the net-chasing treatment may improve adaptability for environmental change and alertness to a novel object. The net-chased fish also exhibited a better survival rate than the control fish, with an odds ratio of 6.76. We suggest that net-chasing training represents an easy and efficient method for improving the behavior of fish for stock enhancement.

Genetic diversity of red sea bream Pagrus major in western Japan in relation to stock enhancement

2001 ◽  
Vol 67 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Ricardo Perez-Enriquez ◽  
Masaki Takemura ◽  
Kazuo Tabata ◽  
Nobuhiko Taniguchi
Keyword(s):  
Genetic Diversity ◽  
Red Sea ◽  
Stock Enhancement ◽  
Sea Bream ◽  
Red Sea Bream ◽  
Pagrus Major ◽  
Western Japan

scholarly journals Singular effects of Bacillus subtilis C-3102 or Saccharomyces cerevisiae type 1 on the growth, gut morphology, immunity, and stress resistance of red sea bream (Pagrus major)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Amr I. Zaineldin ◽  
Sayed Hegazi ◽  
Shunsuke Koshio ◽  
Manabu Ishikawa ◽  
Mahmoud A.O. Dawood ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Bacillus Subtilis ◽  
Red Sea ◽  
Stress Resistance ◽  
Sea Bream ◽  
Control Group ◽  
Red Sea Bream ◽  
Pagrus Major ◽  
Gut Morphology

AbstractThe beneficial effects of Bacillus subtilis C-3102 and Saccharomyces cerevisiae type 1 were tested in red sea bream (Pagrus major) feeds. A basal diet (control) and two other diets were prepared by supplementation with B. subtilis C-3102 (PB) or S. cerevisiae type 1 (PY). After 60 days, both probiotic-supplemented groups exhibited significant enhancement in growth performance, the protein efficiency ratio (PER), and digestive enzyme secretion (protease and amylase) compared to the control group (P<0.05). The anterior, middle, and posterior parts of the intestines exhibited significantly increased values of intestinal fold height (hF), enterocyte height (hE), and microvillus height (hMV) in fish fed PB- or PY-supplemented diets (P<0.05). Serum peroxidase, anti-protease, and bactericidal activities were enhanced significantly in both probiotic-treated groups compared to the control group (P<0.05). Serum and mucus lysozyme activities improved significantly in the PB group compared to the control group (P<0.05). Catalase activity was also significantly decreased in both probiotic groups, with relatively lower activity observed in the PY group (P<0.05). Both probiotic groups showed increased tolerance considerably to freshwater exposure (P<0.05). In conclusion, B. subtilis C-3102 and S. cerevisiae type 1 can be used as functional probiotics to enhance the growth performance, digestion capacity, gut morphology, immune response, and stress resistance of the red sea bream with relatively higher efficiency by B. subtilis C-3102.

scholarly journals Angling gear avoidance learning in juvenile red sea bream: evidence from individual-based experiments

2021 ◽  
Vol 224 (4) ◽  
pp. jeb239533
Author(s):  
Kohji Takahashi ◽  
Reiji Masuda
Keyword(s):  
Red Sea ◽  
Avoidance Learning ◽  
Large Scale ◽  
Sea Bream ◽  
Control Fish ◽  
Red Sea Bream ◽  
Pagrus Major ◽  
Catch And Release ◽  
Feeding Motivation ◽  
Stock Assessments

ABSTRACTAngling gear avoidance learning is a possible factor that contributes to the vulnerability of caught-and-released fish to angling. Whereas past studies suggested angling gear avoidance learning, they were based on large-scale experiments on groups of fish and unable to verify learning accurately. Details of avoidance learning are also unclear. The present study investigated angling gear avoidance learning through a series of individual-based experiments using red sea bream (Pagrus major) juveniles. Fish avoided angling gear after only one or two catches while showing feeding motivation for pellets, representing avoidance learning for angling gear. Most of the experienced fish avoided krill attached to a fishing line, but not krill alone or pellets presented near the angling gear. Experienced fish were less vulnerable to angling than control fish. Approximately half of the experienced fish kept the memory of angling gear 2 months after learning. The learning effect through the catch-and-release procedure would reduce catchability and the value of fishery-dependent stock assessments.

Purification, characterization, and molecular cloning of group I phospholipases A2 from the gills of the red sea bream, Pagrus major

Lipids ◽  
2000 ◽  
Vol 35 (12) ◽  
pp. 1359-1371 ◽  
Author(s):  
Noriaki Iijima ◽  
Satoshi Uchiyama ◽  
Yukichi Fujikawa ◽  
Muneharu Esaka
Keyword(s):  
Molecular Cloning ◽  
Red Sea ◽  
Sea Bream ◽  
Red Sea Bream ◽  
Pagrus Major ◽  
Phospholipases A2 ◽  
Group I
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