Insulin-like growth factor (IGF)-I, IGF-binding protein (IGFBP)-1 and RNA/DNA ratio are endocrine and biochemical parameters used as growth indices in fish, however, they are subjected to environmental modulation. Chum salmon (Oncorhynchus keta) migrate from freshwater (FW) to seawater (SW) at fry/juvenile stage weighing around 1g and suffer growth-dependent mortality during the early phase of their marine life. In order to reveal environmental modulation of the IGF/IGFBP system and establish a reliable growth index for juvenile chum salmon, we examined effects of SW transfer and fasting on IGF-I, IGFBP-1 and RNA/DNA ratio, and correlated them to individual growth rate. Among serum IGF-I, liver and muscle igf-1, igfbp-1a, igfbp-1b and RNA/DNA ratio examined, muscle RNA/DNA ratio and muscle igfbp-1a responded to SW transfer. Serum IGF-I, liver igf-1 and liver RNA/DNA ratio were sensitive to nutritional change by being reduced in 1week in both FW and SW while muscle igf-1 was reduced 2weeks after fasting. In contrast, igfbp-1a in both tissues was increased by 2weeks of fasting and igfbp-1b in the liver of SW fish was increased in 1week. These results suggest that the sensitivity of igf-1 and igfbp-1s to fasting differs between tissues and subtypes, respectively. When chum salmon juveniles in SW were marked and subjected to feeding or fasting, serum IGF-I showed the highest correlation with individual growth rate. Liver igfbp-1a and -1b, and muscle igf-1 exhibited moderate correlation coefficients with growth rate. These results show that serum IGF-I is superior to the other parameters as a growth index in juvenile chum salmon in term of its stability to salinity change, high sensitivity to fasting and strong relationship with growth rate. On the one hand, when collecting blood from chum salmon fry/juveniles is not practical, measuring liver igfbp-1a and -1b, or/and muscle igf-1 is an alternative.
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http://dx.doi.org/10.1016/j.ygcen.2016.07.020 | DOI Listing |
Conserv Physiol
December 2024
Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8564, Japan.
The physiological performance of ectotherms is influenced by temperature, raising concerns about the impact of global warming on ectotherms. Understanding the relationship between ecologically relevant temperatures and the physiological performance of ectotherms provides a basis for assessing their resilience to changing environments. Absolute aerobic scope (AAS) is a functional metric of the thermal performance of aquatic ectotherms.
View Article and Find Full Text PDFPhotodermatol Photoimmunol Photomed
January 2025
Department of Medical Science and Pharmaceutical Engineering, Soonchunhyang University, Asan, Republic of Korea.
Background: Exposure to ultraviolet (UV) light promotes reactive oxygen species (ROS) production and metalloproteinase (MMP) 1 expression, leading to skin damage. Several studies have reported that protein-rich fish byproducts from enzymatic hydrolysis exhibited a variety of health benefits such as antioxidant and anti-inflammation. In the current study, we investigated the protective effect of protein hydrolysate from salmon byproduct (SBPH) in ultraviolet B (UVB)-irradiated human dermal fibroblasts (HDFs) and zebrafish.
View Article and Find Full Text PDFInterspecific competition can significantly impact marine ecosystems by affecting species distributions and abundances. Understanding how sympatric species utilize available food helps identify potential competition and its effects when resources are limited. Here, we applied a suite of analytical methods (diet analysis, stable isotopes, and biomass estimates) to identify potential competitive interactions among North Pacific pelagic predators.
View Article and Find Full Text PDFMicroorganisms
November 2024
Department of Aqualife Medicine, Chonnam National University, Yeosu 59626, Republic of Korea.
Genes (Basel)
October 2024
Department of Pediatrics, Fujita Health University Bantane Hospital, Nagoya 454-8509, Japan.
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