Brown A et al. (2018), Metabolic rates are significantly lower in abys...

ECB-ART-49966

R Soc Open Sci 2018 May 01;55:172162. doi: 10.1098/rsos.172162.

Show Gene links Show Anatomy links

Metabolic rates are significantly lower in abyssal Holothuroidea than in shallow-water Holothuroidea.

Brown A , Hauton C , Stratmann T , Sweetman A , van Oevelen D , Jones DOB .

???displayArticle.abstract???
Recent analyses of metabolic rates in fishes, echinoderms, crustaceans and cephalopods have concluded that bathymetric declines in temperature- and mass-normalized metabolic rate do not result from resource-limitation (e.g. oxygen or food/chemical energy), decreasing temperature or increasing hydrostatic pressure. Instead, based on contrasting bathymetric patterns reported in the metabolic rates of visual and non-visual taxa, declining metabolic rate with depth is proposed to result from relaxation of selection for high locomotory capacity in visual predators as light diminishes. Here, we present metabolic rates of Holothuroidea, a non-visual benthic and benthopelagic echinoderm class, determined in situ at abyssal depths (greater than 4000 m depth). Mean temperature- and mass-normalized metabolic rate did not differ significantly between shallow-water (less than 200 m depth) and bathyal (200-4000 m depth) holothurians, but was significantly lower in abyssal (greater than 4000 m depth) holothurians than in shallow-water holothurians. These results support the dominance of the visual interactions hypothesis at bathyal depths, but indicate that ecological or evolutionary pressures other than biotic visual interactions contribute to bathymetric variation in holothurian metabolic rates. Multiple nonlinear regression assuming power or exponential models indicates that in situ hydrostatic pressure and/or food/chemical energy availability are responsible for variation in holothurian metabolic rates. Consequently, these results have implications for modelling deep-sea energetics and processes.

???displayArticle.pubmedLink??? 29892403
???displayArticle.pmcLink??? PMC5990736
???displayArticle.link??? R Soc Open Sci

???attribute.lit??? ???displayArticles.show???

	Figure 1. (a) Shallow-water holothurian metabolic rate (R) as a function of temperature (T). Shallow-water holothurian metabolic rate increases significantly with increasing temperature assuming an exponential function (solid line: R = 4.702 · e0.0750T; F1,36 = 8.796, p = 0.005, r2 = 0.196). (b) Shallow-water holothurian temperature-normalized metabolic rate (RTN) as a function of mass (M). Metabolic rate data were normalized to a temperature of 2.5°C using a shallow-water-holothurian-derived Q10 of 2.12. Shallow-water holothurian metabolic rate increases with increasing mass assuming a power function (solid line: RTN = 0.5436 · M0.5858; F1,36 = 103.000, p < 0.001, r2 = 0.741). Data from [13,28–41].
	Figure 2. Temperature- and mass-normalized holothurian metabolic rate (RTMN) over collection depth (CD). Metabolic rate data were normalized to a temperature of 2.5°C using a shallow-water-holothurian-derived Q10 of 2.12, and to a standard total wet mass (M) of 70 g using a shallow-water-holothurian-derived mass-scaling coefficient of 0.5858. Blue circles represent shallow-water data (from [13,28–41]), black circles represent deep-sea data (from [10,13,56–59]) and open circles represent data from this study.
	Figure 3. Temperature- and mass-normalized holothurian metabolic rate (RTMN) as a function of in situ hydrostatic pressure (H), oxygen concentration (O2), food availability (FMAX) or light availability (LMAX). Metabolic rate data were normalized to a temperature of 2.5°C using a shallow-water-holothurian-derived Q10 of 2.12, and to a standard total wet mass (M) of 70 g using a shallow-water-holothurian-derived mass-scaling coefficient of 0.5858. Blue circles represent shallow-water data (from [13,28–41]), black circles represent deep-sea data (from [10,13,56–59]) and open circles represent data from this study.

References [+] :

Abe, Pressure-regulated metabolism in microorganisms. 1999, Pubmed