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CloseUp- climbing fish


djsurfs

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Did you see the spiel on whitebait/Banded Kokopu habitat?

I hope it can be found online! i want to watch it again.

it was amazing how the fry can scale pohutukawa roots to get further upstream, or in this case, ropes that have been placed to mimic roots where natural habitat has been disrupted by culverts...

reminds me of "salmon ladders"

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I couldn't find a link last night.... Thanks Zev! :bow:

recently went for a bushwalk and saw a big kokopu in some pools... we headed home wading along the creek but then had to get back on track because there was a set of falls much too daunting to go down & were wondering how the fish get up there.

So, now wondering why does most of the whitebaiting go on down near the sea? do the fish go downstream to spawn? or do eggs or fry just get washed downstream or is there a big migration/ spawning Paarrrrrrrrty? and then only the fittest/smartest/luckiest survive & make it back upstream? do these fish go out to sea part of their life, like salmon?

I guess I need to go find Stella's book! it is available now?

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well, *Inanga* go downstream to spawn...

They move to tidal zones of estuaries and spawn in the grasses that get inundated in teh very high autumn tides. The eggs are left behind when the tide goes down. Two-four weeks later when the big tides come back the eggs get stimulated to hatch. The fry spend around three months in seawater then come in as 'whitebait'. (meanwhile the inanga adults died after spawning)

The others species (koaro, and banded, shortjaw and giant kokopu) do not migrate downstream. Instead in the autumn floods they move to the edges of the floodwaters and spawn there, again leaving the eggs to hatch above the normal waterline. The fry are carried downstream by the following floodwaters. The adults of these species can live at least one decade and probably at least two or more for some of the larger ones.

It is amazing when you think of these climbing fish - and some have been found up 60m waterfalls - such a long way for a 5cm fish to climb. But then think og the fry of that fish... they have to be washed over the waterfall on their way out to sea!! :o

It is highly dubious that they return to the river they were spawned in. Charles Mitchell believes this but I think it is pretty unlikely that they have any homing instinct based on the week or two that they might have been in freshwater. However recent genetic analysis is showing that most whitebait are returning to the same stream, but probably becasue they do not venture far beyond the river mouths, rather than deliberately seeking where they were spawned.

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You're more than welcome to come have a wander around the farm's streams DJsurfs, as we usually go digging around most weekends, it can be really fascinating.

Thanks :) such a neat area you are in,will hafta take you up on that sometime!

And thanks Preach & Stella, great info! it IS amazing. I was pretty high up in the Russell Forest where I saw those fish...

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Thanks Stella, just goes to show you can't always believe what you read huh. My Inanga are almost 16-18 months old now and dowing well. They do show a knack for escapism when I flood the pond, though I haven't seen them climb into the top pond. That would be so neat.

I have seen them happily wriggle across wet rocks to get back into the pond if they escape onto the flooded grass. Bullies, shrimp and Koura all seem happy. My frogs have vanished with the arrival of the cold weather but still got tadpoles swimming about. I was out one night looking around and saw a Koura reach out the water to grab a large pond snail and drag it away into its lair.. So I know there's plenty of food for them in there :)

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