Circulating insulin-like growth factor I in juvenile chum salmon: relationship with growth rate and changes during downstream and coastal migration in northeastern Hokkaido, Japan

Abstract

Chum salmon (Oncorhynchus keta) migrate to the ocean in their first spring, and growth during early marine life is critical for survival. We examined the validity of circulating IGF-I and muscle RNA/DNA ratio as indices of growth rate using individually tagged juvenile chum salmon fed or fasted for 10 days. Serum IGF-I level was highly, positively correlated with individual growth rate. Muscle RNA/DNA ratio also showed a positive correlation, but its relation was not as high as that of IGF-I. We next measured these physiological parameters in chum salmon juveniles caught at river, estuary, port and nearshore of the northeastern Hokkaido, Japan, from May to June in 2013 and 2014, respectively. In both years, there was a trend that serum IGF-I levels were high in nearshore fish and low in river/estuarine fish in June. In contrast, muscle RNA/DNA ratio showed no clear temporal and spatial patterns. The present study shows that circulating IGF-I can be used as a growth index in juvenile chum salmon. Monitoring growth status using serum IGF-I suggests that growth of juvenile chum salmon in the survey area was activated when they left the coast

Comparison between Atlantic salmon Salmo salar post‐smolts reared in open sea cages and in the Preline raceway semi‐closed containment aquaculture system

“…Several studies with teleosts suggest that insulin‐like growth factor I (IGF‐I) plasma concentrations are positively correlated with individual growth rates and can be a useful growth index (Beckman, ; Beckman et al ., ; Kaneko et al ., ). Growth hormone is released from the anterior pituitary and stimulates the production of IGF‐I in the liver, which is the principle source of plasma circulating IGF‐I (Daughaday & Rotwein, ; Ohlsson et al ., ).…”

“…However, it seems that as the fish increases in size, the muscle fibre recruitment contribution decreases while the hypertrophy contribution increases (Stickland, 1983;Weatherley et al, 1980). Several studies with teleosts suggest that insulin-like growth factor I (IGF-I) plasma concentrations are positively correlated with individual growth rates and can be a useful growth index (Beckman, 2011;Beckman et al, 2004a;Kaneko et al, 2015). Growth hormone is released from the anterior pituitary and stimulates the production of IGF-I in the liver, which is the principle source of plasma circulating IGF-I (Daughaday & Rotwein, 1989;Ohlsson et al, 2009).…”

The Insulin-Like Growth Factor-1 (IGF1) System as a Potential Biomarker for Nutritional Status and Growth Rate in Pacific Rockfish (SEBASTES SPP.)

“…To date, only a handful of studies have examined the relationship between Igf1 and growth variation in fishes (Beckman, 2011;Picha et al, 2008a). Igf1 was found to correlate positively with SGR in tilapia (Uchida et al, 2003), coho salmon (Beckman et al, 2004a,b), and chum salmon (Oncorhynchus keta, Kaneko et al, 2015). Generally, studies that have examined associations between plasma Igf1 concentrations and SGR in teleost fishes have observed correlations with coefficients within the range of r = 0.26 to 0.76 (Beckman, 2011).…”

“…It is thought that these changes in plasma Igf1 with food ration result from GH resistance in the liver, as GH levels tend to be inversely related to Igf1 levels (e.g., Fox et al, 2006). Positive correlations between plasma Igf1 and growth rate have been seen in tilapia (Uchida et al, 2003), coho salmon (Beckman et al, 2004a,b), and chum salmon (Oncorhynchus keta, Kaneko et al, 2015).…”

“…For fish experiencing food limitation or deprivation, circulating concentrations of Igf1 decrease while some Igfbps increase, ultimately contributing to reduced muscle and skeletal growth (e.g., Kelley et al, 2001;Picha et al, 2008a;Reinecke, 2010;Shimizu and Dickhoff, 2017). Such declines in circulating Igf1 with food restriction have been observed in a wide variety of fishes, including Mozambique tilapia (Oreochromis mossambicus, Breves et al, 2014;Uchida et al, 2003), Arctic charr (Salvelinus alpinus, Cameron et al, 2007), gilthead sea bream (Sparus aurata, Pérez-Sánchez et al, 1995), and several species of salmonids (Beckman et al, 2004a,b;Bower et al, 2008;Breves et al, 2016;Kaneko et al, 2015;Pierce et al, 2005;Wilkinson et al, 2006). Igfbp expression in fishes has also been found to be responsive to variation in food consumption.…”