Ammonia output by eggs and larvae of the lumpsucker, Cyclopterus lumpus , the cod, Gadus morhua and the plaice, Pleuronectes platessa

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Davenport, John, Lønning, Sunniva, Kjørsvik, Elin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1983
• Subjects: Aquatic Science; Gadus morhua
• Online Access: http://dx.doi.org/10.1017/s0025315400071010; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315400071010

Cod and plaice eggs show a gradually increasing rate of ammonia excretion during development and in neither species was there a great change in individual output at hatching. The rates of ammonia excretion recorded for cod and plaice larvae were similar to those recorded for planktonic Crustacea of comparable size by Conover & Corner (1968). Lumpsucker eggs and larvae have a basically low rate of ammonia excretion (consistent with their slow rate of development and low oxygen consumption), but much ammonia was released from the eggs in the first day or two after spawning. This ammonia was of non-metabolic origin, but was not accumulated from the ovarian fluid prior to spawning. Lumpfish eggs become very sticky when they are first exposed to sea water, but this stickiness is lost within 24 h. Stickiness stems from a viscous elastic slime; it is suggested that the non-metabolic output of ammonia is caused by changes in the composition of the slime as the eggs are bound together in a lattice.