The Company of Biologists

Table 1.

Estimated osmotic contribution of initial osmolytes in the hemolymph and osmolytes produced during exposure of Belgica antarctica larvae to hyperosmotic seawater (∼1000 mOsm kg^–1)

	Seawater (1000 mOsm kg^–1)					Control (freshwater) 6
Days of exposure	0	1	3	6		Control (freshwater) 6
Osmolality (mOsm kg^–1)	407±7^a	491±10^b	646±12^c	779±15^d	391±10^a
Total body water content (g H₂O g^–1 DM)	2.51±0.07^a	2.17±0.05^b	2.07±0.03^b	1.89±0.05^c	2.46±0.06^a
Osmotically active water (OAW)content^{^*} (g H₂O g^–1 DM)	2.04	1.72	1.63	1.46	1.99
Loss of OAW (%)	–	15.7	21.1	28.5	–
Osmotic contribution of original solutes due to loss of OAW (mOsm kg^–1)	–	480	516	569	–
Osmolyte concentration (μg mg^–1 DM)
Glycerol	2.17±0.27^a	2.96±0.46^a	6.87±0.58^b	9.56±0.46^c	1.94±0.31^a
Glucose	3.75±0.34^a	4.71±0.42^a	8.30±0.48^b	12.68±0.54^c	3.82±0.28^a
Trehalose	4.91±0.31^a	6.62±0.36^b	9.11±0.41^c	14.38±0.53^d	4.23±0.37^a
Osmotic contribution of synthesized osmolytes^{^†}(mOsm)	–	11	54	108	–
Total explainable osmotic pressure (%)	–	∼100	88.2	86.9	–

	Seawater (1000 mOsm kg^–1)					Control (freshwater) 6
Days of exposure	0	1	3	6		Control (freshwater) 6
Osmolality (mOsm kg^–1)	407±7^a	491±10^b	646±12^c	779±15^d	391±10^a
Total body water content (g H₂O g^–1 DM)	2.51±0.07^a	2.17±0.05^b	2.07±0.03^b	1.89±0.05^c	2.46±0.06^a
Osmotically active water (OAW)content^{^*} (g H₂O g^–1 DM)	2.04	1.72	1.63	1.46	1.99
Loss of OAW (%)	–	15.7	21.1	28.5	–
Osmotic contribution of original solutes due to loss of OAW (mOsm kg^–1)	–	480	516	569	–
Osmolyte concentration (μg mg^–1 DM)
Glycerol	2.17±0.27^a	2.96±0.46^a	6.87±0.58^b	9.56±0.46^c	1.94±0.31^a
Glucose	3.75±0.34^a	4.71±0.42^a	8.30±0.48^b	12.68±0.54^c	3.82±0.28^a
Trehalose	4.91±0.31^a	6.62±0.36^b	9.11±0.41^c	14.38±0.53^d	4.23±0.37^a
Osmotic contribution of synthesized osmolytes^{^†}(mOsm)	–	11	54	108	–
Total explainable osmotic pressure (%)	–	∼100	88.2	86.9	–

Values are mean ± s.e.m. Different letters indicate significant differences between days of exposure (ANOVA; Bonferroni-Dunn test)

OAW was calculated from Worland et al.(1998). [(OIW) = 0.069(TBW) +0.3, where OIW is osmotically inactive water content, TBW is total body water content and is the sum of OIW and OAW]

†

Assuming that osmolytes are only dissolved in OAW

View Large

This Feature Is Available To Subscribers Only