Where do Jacks Breed..?

[supertuned]

the EAC is kickn hard in summer and get a SE wind the eddies push right into the coast, thats why marlin and so forth wander right in sometimes, microscopic fry could easily ride in that and get far enough that once in the green water direction is easily sensed. There are plenty of big reef jacks not to far from the coast in SEQ but also some a long way out. even thou you would assume far NQ always has millions more jacks than SEQ anyone thats fished there will know the waters not affected inshore by the EAC anywhere as much and pretty green, maybe more fry simply find there direction better than they do in SEQ

[gecko]

Nothing like a jack thread to get everyones opinion, lol...........

The research is divided, becuase we dont have many good studies on jacks. The few that Ive read from dpi say that jacks reach sexual maturity at 50-60cm, and head out to the reefs to breed. Breeding size jacks are just not found in esturies, except for rare cases.

theres no surprise about about small fish finding there way up to the back creeks, most other species do it too.

Id say any fish that is landlocked in a small lake would stop breeding.They dont want offspring competing for the foodsource. Most caged animals dont breed in zoos, so why would fish? It would be interesting to hear from the fish stockists on this. Do fish have hormones that shut down when stick in confines?

cheers
Andrew

[mylestom]

Would love to hear from Kurt on this, he has successfully breed them and with his qualifications, I am sure he could enlighteen us all.

[ActiveAngler]

I think that jacks and jungle perch have similar habits. Both breed outside of the river systems, JP's inshore reef habitats for breeding, jacks inshore and offshore breeding locations. I also think that the jacks up to about 60cm will venture to inshore reefs during the breeding cycles and return to the creeks soon after. Why? Because of the numbers of jacks i have seen that are about 35-60cm on inshore reefs during the breeding season at some places i have dived in CQ and NQ. A week later there were none in the area. I dunno, maybe they have a few dry runs before productive breeding takes place??

I agree with you mate, for the same reasons,the large numbers of big jacks i have seen diving at the mouths of estuarys,with big schools of large fish there one day,gone the next...then back again a month or so later,for a week or so. Im guessing like everything,some of the fish stay on the reef,and some head back in.