My bully has eggs!

[BigBossPants]

Woo hoo!

I have 3 common bullies (I think) in a 55l tank, they are about 7cm long. The largest one turned totally black 2 days ago and has been guarding its cave very strongly. Today I lifted its rock to do a water change and it was covered with eggs!!

Do I need to do anything special to make Mrs Bully happy, or will she do everything she should?

Should I remove the other two bullies or the eggs or will they grow up ok in the same tank?

Filtration is an aqua one CF500, water changes are 50% weekly, diet is a frozen puree of heart, liver, fish, kidney, vegetables and garlic.

[Stella]

Oooh congratulations!

And I believe you will find that it is Mr Bully doing the work

Here is what bullies do:

Male establishes a nest site, usually under a stone.

He gets really stroppy and drives everyone away.

He will frequently turn black when being defensive,

and spend his time popping in and out of his nest trying to attract attention to himself and his nest.

Eventually a ripe female gets attracted by this display of testosterone ( :roll: )

She will turn very pale golden and start laying her eggs upsidedown on the ceiling of the nest, in a tightly-packed single layer.

He will turn quite black and take turns between buzzing around and fertilising the eggs.

This takes many hours.

Then she sods off and leaves him to it.

He is a very attentive father - fanning the eggs with his pectorals to oxygenate them and reduce silt etc build-up, and chasing off others.

However he isn't very loyal and will try to get as many females to lay in his nest as possible.

When they hatch he leaves them to their own devices.

They take 2-3 weeks to hatch (temp dependent) and after one week you should start seeing little eyes staring back at you (SO CUTE!) though common bully eggs are pretty tiny (1.5mm compared to 2-2.5mm for non-diadromous bullies).

Now, being diadromous it is unlikely that they will survive. Diadromous fish go to sea after hatching, which is somewhat hard to stimulate in the aquarium! However it is possible, if they came from a lake or well inland and the eggs are big, that they are from a non-diadromous population of commons...

Sorry to deflate your excitement... but it is still pretty cool! Neat behaviours to watch and shows that you are doing things just right

[BigBossPants]

They are from lake Tarawera... Any idea what species are found there?

I suspect that daddy is either a Cran's or Upland, he has quite a blunt face and a yellowish stripe on top of his first dorsal fin and the base of his pectoral fin. His face has some broken squiggly markings on it, kind of an orangey colour. The other two look like common's to me, I will try to load pics if I can. The eggs are tiny, they look like less than 1mm and are a pale colour.

Can different species interbreed?

How soon after hatching would they head to sea if they indeed need to do this? And at what pace should the salt be increased?

I have never bred any kind of fish and would really like the babies to survive. Would it be best to wait until they hatch before moving them to a nursery tank or should I take the rock out just prior to hatching? I suspect newly hatched fry would be a tasty treat for the other fish in the tank, any idea if the dad will eat them too?

[Ira]

Now, being diadromous it is unlikely that they will survive. Diadromous fish go to sea after hatching, which is somewhat hard to stimulate in the aquarium! However it is possible, if they came from a lake or well inland and the eggs are big, that they are from a non-diadromous population of commons...

Sorry to deflate your excitement... but it is still pretty cool! Neat behaviours to watch and shows that you are doing things just right

May not be that hard to simulate if you have some kind of time range from hatching to reaching the ocean. I'd imagine a couple weeks?So you could give them a week or so in freshwater to as they travel down stream then over another week raice the salinity of the water by maybe .002-.003 each day until reaching full marine?

[Matto]

will they die if not gradually introduced to marine water?

[livingart]

i have some saltwater rotifers if you need them

[Stella]

While it seems an insane amount of faffing around, if anyone has a stupid amount of time of their hands and wants to try this...

This paper goes over a technique for raising diadromous inanga (the most common whitebait, a galaxiid, not a bully/gobiomorphus) in the lab.

http://www.informaworld.com/smpp/conten ... a920426973

I don't know if it has been tried on bullies.

People tend to estimate much faster times to sea, though I guess it depends on flow conditions and distance inland. Given that diadromous common bullies are normally not too far from the coast (can't remember, something like most under 30km inland?), they probably get there pretty fast.

[BigBossPants]

I'll have a read thanks

If they aren't a diadromous species, the salt will kill them yes? Still not 100% what species they are as dad looks very different to the others.

[Stella]

What the adult looks like should have little effect. The only physical difference that I am aware of is the sensory pores on the head (fewer in non-diadromous ones).

The main difference that you can easily spot is egg-size. I don't have the right book on me at the moment, but I think non-diadromous SPECIES have 2-2.5mm long eggs, while diadromous SPECIES have 1-1.5mm long eggs.

I do not know if there is a size difference between diadromous and non-diadromous forms of the same species. It is a possible convergent evolution.

Salt probably won't kill them. All native fish have diadromous ancestors. Not sure about hatchlings though.