Antifreeze activity in the gastrointestinal fluids ofArctogadus glacialis(Peters 1874) is dependent on food type

Abstract

2.04±0.30°C was observed in the intestinal fluids of fish feeding on B. saida. Native gel electrophoresis revealed that the gastrointestinal fluids contained AFGPs in all the different size groups. However, differences in band intensities for the two food types suggest that the ingested food has an influence on the concentration of the different AFGP-sizes in these fluids. A decrease in band intensities combined with a drop in thermal hysteresis from mid-gut to hind-gut fluid suggests that absorption of AFGP or possibly degradation occur during digestion.

Nonhepatic origin of notothenioid antifreeze reveals pancreatic synthesis as common mechanism in polar fish freezing avoidance

“…For fishes that possess other types of AF protein, presence of intestinal AF is demonstrated for the type III AFP-bearing Antarctic eelpout L. dearborni (Figs. 3 and 4B) in this study, and recently for the AFGP-bearing Arctic ice cod A. glacialis (36), both of which show pancreatic mRNA expression of their respective AF (see L. dearborn and A. glacialis in Fig. 5).…”

De Novo Gene Evolution of Antifreeze Glycoproteins in Codfishes Revealed by Whole Genome Sequence Data

“…The time period when freezing temperatures appeared in the Northern Hemisphere is shaded in blue ( Eastman 1997 ). Species shown to have functional AFGP and thermal hysteresis are denoted with (+): A. glacilis , B. saida ( Praebel 2005 ), G. chalcogrammus ( Tsuda and Miura 2005 ), and G. morhua ( Hew et al. 1981 ).…”

“…1 B ), all of which have been shown to have antifreeze activity in their blood ( Hew et al. 1981 ; Praebel 2005 ; Tsuda and Miura 2005 ). Furthermore, we found some segments of afgp in Merlangius merlangus , but just like in its sister species M. aeglefinus a 3′UTR sequence was not detected, suggesting these two species only possess an afgp pseudogene ( afgpψ1) .…”

Cod movement ecology in a warming world: Circumpolar arctic gadids

“…Despite tolerance of sub-zero temperatures, B. saida are considered to prefer waters >0°C, depending on region and life stage (Drost, Fisher, et al, 2016;Schurmann & Christiansen, 1994;Table 3b). Partly attributed to life stagespecific concentrations of antifreeze glycoproteins (AFGP; Fletcher et al, 2001;Praebel & Ramløv, 2005), body size and life-stage segregation with depth is common with young-of-the-year (YOY) most often occurring in the epipelagic layer at <100 m, while juveniles 1-year + occupy the mesopelagic layer at <400 m, but often <250 m depending on season and region (Cohen et al, 1990;Geoffroy et al, 2016;Majewski et al, 2015). For example, during the transition to the ice-free open water season, B. saida move deeper to stay within the mesopelagic layer that shifts from 200-400 m during winter to 600 m+ in summer in the Beaufort Sea (Geoffroy et al, 2011(Geoffroy et al, , 2016.…”

“…Until relatively recently, the movement ecology of fishes in the Arctic was determined primarily by fisheries catch data and the gut contents of predators (Hollowed et al., 2013). More advanced techniques, however, are now providing biological and physiological support to observed species' distributions and movement behaviours, including chemical tracers to infer diet and foraging location (Brewster et al., 2018) and analysis of antifreeze protein structure to understand adaptation to extreme environments (Devries & Cheng, 2005; Fletcher et al., 2001; Præbel & Ramløv, 2005). Physiological constraints on movements are further being explored through controlled laboratory experiments examining thermal tolerance (Drost et al, 2014; Drost, Fisher et al, 2016; Drost, Lo et al, 2016), temperature‐dependent growth and swim speed (Laurel et al., 2016; Schurmann & Christiansen, 1994), and metabolic rate (Kunz et al., 2016).…”