Experiments on the Respiration and in situ Development of Baltic Herring (Clupea harengus L.) Eggs

✍ Scribed by Prof. Dr. Erich Braum

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 915 KB
• Volume: 70
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.19850700108

✦ Synopsis

A primary blastodisc develops 2 hours and 40 minutes after artifical fertilization a t 8 O C and 15 Oho S. The egg then begins embryonic development. When incubated in water with the oxygen concentration reduced t o 50 O/,, or 15 0/0 saturation, the oxygen consumption of the eggs decreased t o 73 O/o or 41 O / , , of normal, respectively. For the i n situ experiments, eggs and sperm taken from living fishes were spread on Plexiglas plates in a way that monolayers adhered t o the surface. The plates were then moored to buoys a t two depths in a spawning area a t Potenitzer Wiek near Travemunde. Egg mortality increased with the duration of incubation. About 90 O/o of the spring spawn died before hatching, but only a 10 O/o mortality occurred among those spawned in autumn. Scanning electron microscope examination revealed structural changes on the egg surfaces caused by bacteria and particles of sediment. The role for survival of the pattern formed by the eggs as they adhere t o the surface is discussed.

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