Stella

phthththtbtbtbtb! to everyone putting down the little brown fish! They also come in grey, olive and sandy brown, with touches of silver, gold, yellow, bright orange, bright green and... brown. Blair, you live in the right town! I would be more than happy to show you my natives and take you fish hunting if you wish Have a look at my photos and videos linked below, and there are a lot of threads (even a whole natives section of the forum!). (a hydrologist you say? Are you going to the freshwater sciences conference? )

yeah, some tanks have a fairly immediate die-off, others take longer. In my tanks I had to do the seven day one, and there was no sudden die-of, it just gradually reduced over that time. Took a *very* long time to come back too! (But of course, after you dose it you should be figuring out what caused the nutrient imbalance and making sure it doesn't happen again)

nice! The one on the towel is interesting,shows the shape really well. What prompted that? Did you have to splay the fins? (and did you and the camera get soaked when it flicked up?

I suspect I had little to do with me and more to do with ripe little fishies suddenly finding themselves in close confines and making the most of it! Someone is thinking! Actually, no, these ones are spring spawners and the kokopu are autumn spawners. It relates to diadromy and where the food is. There is not a great deal of food for fry in streams apparently, but there is more over summer than winter. So those that are non-diadromous tend to spawn in spring. The diadromous kokopu spawn in autumn. There is a lot of food for a growing fish in the sea, then when they come back in spring as whitebait they find there is a lot of food in the freshwaters now. Just to completely screw up my theory, both diadromous and non-diadromous bullies spawn in spring. The only timing difference is that the non-d ones spawn in spring *and* summer. But one really interesting thing here is when the common bullies form landlocked populations. A study looked into the differences between the common bullies in a lake and those downstream from the lake in a river. Ones in the lake were non-d and the ones downstream were d. The non-d ones spawned in summer, because the lake would be too unproductive over winter to support fry. The fish downstream spawned over winter/spring. These were part of many factors (including genetics) that indicated that the two populations are diverging. This morning I can see six eggs. One looks milkier than the rest so maybe that one is not fertile. I will pull them out today and put them into another tank.

Male redfin bully. The females have similar patterning but brown where the red is. Bullies are awesome in the aquarium - so territorial and active!

*I* mean ASAP! I wanna get working on this properly!!! :bounce: Not sure when it will be open, but this summer sometime. Of course everyone will be told (sorry to hijack thread...! back to importing cherry shrimp...)

Trout are semi-ok. Yes they kill stuff (Lake Taupo used to be so thick with koaro the Maori would pick the off the beaches after strong winds, a few years after trout were introduced the population crashed). But without trout there would be a whole lot less interest in trying to clean up our rivers and streams. Unlike most other introduced species, trout like the water clean and cool, like the natives. In that sense they are an 'honorary native' for some biomonitoring purposes. They are also considered to be part of the ecosystem now, not ideal, but not going to have population explosions and wipe everything out,or change the habitat like possums. But yes, encourage him to catch as many as he likes Dwarfs are in the South Island, see map: http://www.niwa.co.nz/our-science/fresh ... f_galaxias Tis an odd distribution but quite a few plants and animals have a similar one. Relates to land moving and the cook strait being connected during the Pliestocene.

I have heard of people wiring up banks of computer fans Fans can be noisy though. I think it will depend on a whole bunch of things though: The room should be cool to begin with. The surface area should be vast. If your tank is tall and thin forget it. You want maximum water surface area for evaporation. Your fish should be rockpooly. They can be a bit more hardy when it comes to temps. The aquarium hardware should give off as little heat as possible and insulate the tank thoroughly. Of course I haven't had any experience with marine fish. Others will be able to give you more specific advice.

Well, the adults are in quarantine, and only days into it, which makes things awkward. I will see what I can find under the rocks later, and see if they are fertile. Of course no one knows if the adults are inclined to cause any damage.... Of course if the adults come down with anything I will have to remove the eggs if I want them to survive treating the adults. Quite what I would put them in I do not know! Actually, I know a scientist in the South Island who breeds different non-diadromous galaxias species, she may have some ideas, or have bred these guys before.

700L is pretty big, should be reasonably stable. Reading through thread after thread here on good ways of cooling, it looks like chillers are good on small tanks and fans for big tanks. With a sump you could have a fan on the tank and a fan on the sump. Of course you would need to be topping off with fresh water very regularly.

sigh, spoke to soon. I am almost embarrassed to say: they have now spawned in my tank.... I can see 3 spherical 2mm long eggs. The fish are all hiding and I suspect there may be more eggs under the rocks but I will leave them to it.

Nope, Ira's not a stirrer! Not a boring brown lump: Piggyvir, actually some people are selling them to petshops, namely Mahurangi Tech. While they are doing some breeding, a decent proportion of our native fish can not be bred in captivity because the juveniles need to go to sea for a few months after they hatch (hence the whitebait runs of all the juvenile fish returning from sea). I have written a book on keeping native fish in aquaria (nearly published) and am generally trying to encourage the hobby so that people become more aware of their existence. I had not heard of them myself before I saw them in a tank at the pet shop! I am involved in creating this awesome public native aquarium in Turangi, and the aquarium water discharges into a stream that goes to Lake Taupo. You wouldn't believe the mental gymnastics involved in trying to come up with a way of not spreading any new organisms into the lake - pest fish, diseases, didymo, zooplankton, phytoplankton etc! We do not even know what we are guarding against (are there catchment-specific diseases etc?) nor can we even see what we are avoiding, so a fish may get through quarantine fine but then some nasty might be lurking in the water that then destroys the Taupo trout fishery! I *know* it is overkill, but we have to be doing it by the book, and much though I dislike trout, I don't want that on my CV!

well, filter feeders suck up water, filter out all the lumps, and spit the water out again. They are like a living mechanical filter. They will eat single-celled algae and bacteria that cause green or cloudy water. They won't eat algae that is stuck on or large bits, like hair algae. Of course they are a sort of long-term project - they will gradually build up to a working population that keeps the water nice and clean for you fairly permanently. In the mean time, green water is usually caused by too much sun. If the green water is a new thing it is probably because the change in where the sun is at means your pond is getting too much sun. Can you give us some more details about your pond? How big it is, how long established, etc etc etc?

I doubt it, they eat tiny amounts of fixed algae. I am playing with the idea at the moment of using filter feeding molluscs for bacterial bloom issues. There is a tiny native bivalve with a variety of names (pea mussel, pea clam, fingernail clam, fingernail mussel, inSpheridae family). They get to no bigger than 10m, usually 6mm,are fairly symmetrical, a domed fragile shell and a pale pink colour. They can reproduce in captivity. They are super cute and whizz around really fast! This is a really teeny one: I have some in my critter tank, which has a leaf litter bottom and had terrible bacterial blooms. Since I put some pea mussels in there I have had no problems. I really want to get a whole lot for my mudfish tank as that has awful bloom problems from the leaf litter. You can find them in lowland farm troughs and silty, slow-flowing soft-bottomed streams. They are fairly common and widespread. Unfortunately I must recommend against using the native freshwater mussels frequently for sale in pet shops. They are in serious decline in the wild and recruitment of juveniles is terribly low, partly due to the decline in a native fish that is host to the juveniles. I imagine most pet shops are unaware of the conservations issues (or that it is virtually impossible to not starve them slowly to death in aquaria).

The nearest stream

I would be worried about the strength. Most polyboxes are quite thick and being formed in one with thick curved corners is a lot stronger than gluing slabs together. Cardboard boxes would probably work better and be less hassle.

oh cool! Thank you

hehe indeed! Various bits of recent research on co-existence of certain non-diadromous galaxiids with trout tends to show that where there are distribution overlaps, there is a usually trout-free breeding population upstream that is supplying galaxiids to the trout/galaxiid area. Take away that population and the lower one dies out. Similarly in braided rivers there can be side-braids that are not suitable for trout, so the galaxiids hang out there. Abstract water for farming irrigation and the side-braids are lost and so are the galaxiids. I am looking forward to my dawrfs coming out of quarantine in a few weeks so I can put them in with my other dwarf - I want to see him all excited about getting some new friends!

They don't need salt to live, but I *think* they need it to reproduce. Not sure if it can be done in captivity easily.

awesome!! Ok, can someone please explain the difference between polypterus, birchir and delhezis?? They are beautiful fish, they look so much like the native mudfish, but much older.

Thanks It should be possible to breed them, not sure if anyone has. Very little is known (ie published) about these guys.

I did a trip on the weekend with a couple of friends to the Manawatu headwaters (inland from Norsewood) to find some dwarf galaxias - Galaxias divergens They are a teeny native, same family as the whitebait but they don't go to sea. They don't get much bigger than a large whitebait (circa 5cm). They live in fast flowing, bouldery headwaters, and have been decimated by trout. They look a bit like a koaro, and move like one, but have much smaller fins and a really blunt face, and seem to be upper-water drift-feeders. More info and a distribution map: http://www.niwa.co.nz/our-science/fresh ... f_galaxias I already have one in my riffle tank, but wanted to get him a few friends. To took a while to catch any, but now I have seven dwarfs in the quarantine tank! :lol: The photos are about as good as I can do at the moment given the state of the tank and how tiny and timid the fish are!

they were filed under weasels, they are the water variety ...

if you quarantine and done then you don't have to dose your already clean fish, nor do you have to worry about all the other diseases the new fish are potentially bringing in. *All* new things should be quarantined and observed to be clean for 2-4 weeks before you introduce them to your tank. How do you know the parasites are causing problems? I did a bit of research into internal parasites (my fish are all wild) and came to the conclusion that the chances of a parasite actually causing any problems was pretty low. With fish it is very hard to tell if they have them, and even if they do and you worm them there is a very low chance you will see any change in condition. The parasites actually want to be pretty benign - your host getting sick and dying is not helpful to the host. My native parasites tend to have different stages requiring different hosts, so the chain is broken once they are in the tank. Anyway, that is my $0.02 on different fish, your mileage may vary.

Are you even thinking the consequences through at all?? :evil: This is not just the silly laws being all mean and making it sooo harrrd for the nice little hobbyists to get perfectly charming pets into the country! Think varroa mite. Think painted apple moth. Think old man's beard. Rats, mice, possums, ferrets, stoats, weasels. White butterfly, garden snails, on and on and on. Think every freaking weed and annoying pest. Almost all of them are exotics and the result of accidental importation or poorly researched intentional introduction. The weeds clogging our streams mostly came via ponds and aquariums. No matter how wonderful these shrimp might be, or how little risk *you* think they pose, you still have to go through the same process.