Premium
Osmotic and structural changes during early development of eggs and larvae of the cod, Gadus morhua L.
Author(s) -
Davenport J.,
Lønning S.,
Kjørsvik E.
Publication year - 1981
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1981.tb05835.x
Subject(s) - gadus , biology , atlantic cod , salinity , osmotic concentration , perivitelline space , fishery , larva , zoology , anatomy , ecology , fish <actinopterygii> , biochemistry , embryo , oocyte , zona pellucida
Newly extruded cod eggs have a similar osmoconcentration ( c. 400 mosmol kg ‐1 ) to maternal blood, maternal ovarian fluid and paternal semen. After extrusion, average egg osmolarities rise rapidly to about 520 mosmol kg ‐1 but this is entirely due to the cortical reaction resulting in the formation of a perivitelline space filled with fluid isosmotic with the external medium. The ovoplasm remains at around 400 mosmol throughout development; free swimming cod larvae also possess body fluids of this concentration. Over the salinity range 10.2‐37.4% 0 , salinity had no effect on egg dimensions and average egg osmolarities were consistent with a model assuming changes in perivitellic fluid concentration only.