| Popis: |
The spawning habitat of jungle perch is unknown. It coexists in the short, fast-flowing freshwater streams of north-eastern Queensland with sooty grunter, a known freshwater spawner. The duration and intensity of sperm motility in various dilutions of sea-water were compared to indicate whether jungle perch spawn in fresh water or salt water. Sooty grunter sperm was most active in salinities of 0 g l-1 and 5 g i-1, and not motile in salinities above 15 g l-1. Jungle perch sperm was not motile in fresh water, but most active in 25 g I-1. These results, together with fish distribution studies in estuaries, indicated that jungle perch probably spawn in the sea in salinities above 25 g I-1.. |
