Are my blue-green Chromis Spawning?

[JoeVandal49]

So i have a group of 4 blue-green chromis.

I started out with 4, lost three to my carpet anemone, decided that was that, and didn't get any more for about 6 months.

So i had the original chromis that lived for 6 months and it had gotten fairly large when i added the new three.

The new 3 consisted of one that was the almost the same size as my original (large), one medium, and one small.

My original put them in line for the first week, but since then there has been no aggression(other than the largest making sure everyone knows its boss, getting to the front of the group at feedings, etc).

They had been in my 55g mixed reef for about three months. They always stick together, but over the last month i have noticed a bit of pairing going on.

A week ago they went into the new 72x18x19 100g.

The last three days my second largest has been hiding in a crevice which seems to be at the base of the rockwork where it has access to the sand bed, but i cant get a view into the crevich (tight entry opening, but opens up like a cave inside). I can just see the fish coming and going from that entry.

The three other fish are in the water column every day as normal. The fish in the cave stays in there all day except at feedings. At feedigns it darts from the cave, quickly rejoining the group where it quickly eats before heading straight back to the crevice.

Could this be a male guarding a clutch of eggs? Has anyone else experienced similar behavior?

I couldn't find much info it seems they are not captive bread much since there wouldn't be any monetary value to breeding them.

Thanks for any opinions on what this behavior could be.

 

[ThRoewer]

As far as I know Cromis lay their eggs, like Dascyllus, at the base of their home coral. Though other damsel fish like yellowtails lay their eggs in caves (I had them lay their eggs on the inside of ceramic flowerpots), so it is quite possible. Usually the eggs take a week to hatch. If after that time they come out again I would say they spawned. You can also look out for the hatched larva.

 

[snorvich]

Most likely they are "reducing the herd". chromis do that.

 

[lifeoffaith]

I had three in a 120 that ended up being two because they just pestered the last one. I'm surprised they even got along at all in the 55, but the 100 is still a toss up. Typically with a large tank you can get away with a few, but sometimes they just decide to take one out.

 

[JoeVandal49]

Thanks for the responses!

I had considered a purging of the herd, but i really don't think that is whats going on here but i certainly could be wrong as i often am.

The fish has no problem joining the group at feedings, and i have seen no aggression when the fish joins. It literally comes out, stays out the entire feeding until food is consumed, then returns. On top of that, i would think the smaller fish would be purged from the group first, but i guess that may not be the case.

I have also heard that even numbers are better to help control aggression, as they will sometimes pair off, so that's why i have stuck with the number 4. I'm not saying that they wont reduce so please don't think that's my response here, and on the contrary, after everything i read prior to purchase, i always expected them to dwindle over time, i just dont think this is the case in this instance.

From what little info i have gathered from other sources, it seems chromis build a nest in the sand bed where the female lays, then the male protects the nest. Can anyone confirm this is the case?

I really wish i could get a good look in there lol.

 

[ThRoewer]

Chromis don't build a nest in the sand. They ether lay their eggs openly at the base of their home coral (like clownfish do next to the foot of their anemone). Some other damsel fish lay their eggs in holes, gaps, empty shells, little overhangs or whatever else covered space is available.
The largest and dominant of a group is usually the male and if that's the one who is disappearing they most likely have eggs.

Here you can read more: Rearing Green Chromis

 

[JoeVandal49]

Thanks for the link!

Yes, it is one of the two largest. It is pretty much exactly the same size as the one i had from the previous 4 where i lost 3 to a nem. It is the new addition however and not the original.

My google foo is sub par. All the info i was getting was from really old threads on different boards and could very well have been the same person discussing the "sand nest" on all those boards. LOL

Thanks!

 

[JoeVandal49]

All 4 are back together in the water column today.

 

[JoeVandal49]

Well all were together for a couple days in the water column all day, now the largest and most dominate fish is in and out of the "cave" the last two days or so. Same location, different fish.

It was the second largest fish last go round.

 

[kizanne]

You can't see into the cave at all? They may be cleaning the surface in preparation of a spawn. Most fish get a little fat before laying eggs. I'm not sure if Chromis do.

 

[JoeVandal49]

Unfortunately i cant see into this spot at all. It has a tiny access and opens into a larger "cave".

Access is barely large enough for the fish to access.

Is there any good way to accurately "sex" chromis? I have been trying to watch and see if one of them looks gravid and maybe a female, but i honestly don't know exactly what im looking for. They have all gotten really fat and look really healthy in my care. I work from home and feed frequently throughout the day. The only experience i have of this nature is with Dart Frogs.

 

[JoeVandal49]

Same behavior, only now the two largest are switching off being in the cave. Seems the largest was going in last week for 1-2 days at a time. Then the second largest is in for the remainder since then till now.

Maybe the largest is a female and was laying, and the second largest is the male and he is now watching?

I'm stumped. All of them seem healthy and happy, and group together at feedings etc. Aggression which was minimal to begin with has been non existent since the Mimic lemon peel tang/ Lamarcks Angel went into the display.

 

[JoeVandal49]

This group of 4 is still going strong. Here is a pic taken today. Still exhibiting same behavior. If work wasn't so busy i would try to do some more documentation.

 

[JoeVandal49]

All 4 are still going strong.