Halfbeaks - Fighting, Breeding

[0x0000ff]

Hey all

I've had these particular halfbeaks for around 5 months without any dramas, and I have a bunch of other halfbeaks (same species, same fish store) for well over a year.

2 of them started fighting a couple of days ago, i've never seen any of my halfbeaks act like this before.. it seems a little too violent so I thought i'd check (most likely with nmonks halfbeak wizard )

click the thumbnails to open (much) LARGER version of picture










Yes, their beaks are bent. every halfbeak i've ever bought had a bent beak at time of purchase. the only ones I have that don't have bent beaks are 2nd generation captive-bred



Do you think they'll be ok? There's 9 in the tank including the 2 which are fighting. 3 males 6 females.

 

[nmonks]

Those are wrestling halfbeaks, Dermogenys sp., and the males fight. They're used in the same way as Siamese fighting fish in parts of Asia, as "sport fish" for gambling. So the males are going to fight whatever you do, and they aren't going to stop.

In my experience, male Dermogenys and Nomorhamphus ("Celebes") halfbeaks are all fairly aggressive towards one another. It's best to keep either a single male per tank or lots of them (say, ten) so that you either have no aggression or aggression that is so spread out it doesn't do any harm. When I have kept three Nomorhamphus males in a 180 litre tank, one male becomes dominant and swims at the top, and the other two end up looking slightly battered and hiding at the bottom of the tank.

Bent beaks on halfbeaks can be because the beaks are normally bent (as with N. liemi, where the male has a curly beak). But in your case it is because the fish have either been fighting and broken their beaks or else bumped into the glass and damaged them. Both of these is fairly common. You can avoid having the fish bump into the glass by putting tall plants or rocks around the edges so that the fish has a sense of "boundaries".

Anyway, your fish will likely be fine provided you can moderate the male-male violence a bit. A bigger tank, more plants, or removing all but one male would be possible solutions.

Cheers,

Neale

2 of them started fighting a couple of days ago, i've never seen any of my halfbeaks act like this before.. it seems a little too violent so I thought i'd check (most likely with nmonks halfbeak wizard )

Yes, their beaks are bent. every halfbeak i've ever bought had a bent beak at time of purchase. the only ones I have that don't have bent beaks are 2nd generation captive-bred

Do you think they'll be ok? There's 9 in the tank including the 2 which are fighting. 3 males 6 females.

 

[0x0000ff]

OH ok thanks heaps for the reply.

You know your halfbeaks so I'll take your word, but see the problem is none of them have ever done this before.. and as I said i've had these fish (not this exact pair) since august 2005 !

and are you saying both fish in the 2nd picture are male? In the larger version you can see their fins side on. I don't understand the whole almost-gonopodium thing... I've been trying to track their gender by remembering which have fallen pregnant before.

 

[diburning]

they are dermogenys sumatrana.

 

[nmonks]

Like people, the behaviour of fish isn't 100% predictable. I've seen aggressive angelfish and pufferfish that liked company... So what normally happens isn't what always happens.

Anyway, perhaps the males have only just become sexually mature? Or perhaps something changed in the aquarium that threw out the original social hierarchy? Males and females will fight with each other, too. Females will also fight with each other. In fact halfbeaks just like fighting, as far as I can tell!

OK, sexing halfbeaks. Females are usually bigger and less colourful. Males are smaller and in Dermogenys spp at least have bright red and/or yellow markings on the unpaired fins.

Some species aren't that brightly coloured, in which case you do need to go by the andropodium (gonopodium is only on poecilids and goodeids). If you look at the anal fin of the females, it is obviously triangular and shaped more or less like the dorsal fin. On males, the anal fin looks like someone took a knife and sliced off the bottom half of the anal fin, so it has a sort of irregular shape, flat towards the front and then triangular at the back. It is a different shape to the dorsal fin.

Male halfbeaks also usually have longer beaks, though if they've been fighting this isn't always obvious.

Anyway, in this photo of yours, the male is on the left and the female is on the right. Note the shapes of the anal fins are quite different, and that the female is very solidly build around the chest, where the male is quite spindly. I'd say these are testing each other out prior to mating and wouldn't worry about it. The females are well able to handle themselves and take no nonsense from the males!

Hope this helps,

Neale

 

[0x0000ff]

Thanks again!!! I've learnt more about halfbeaks on this forum then I have everywhere else combined.

If you want to use my photos for your wikipedia article I don't mind, i haven't seen many hi-res photos of them online.

 

[0x0000ff]

2 hours after I posted the last message, I was changing the water in the tank, and ...




Hurrah There's 12 of them, this is the 1st time this halfbeak has given birth. An older far more experienced halfbeak is in the same tank and she looks to be days away from birth too. Happy times

 

[nmonks]

Very nice. Keep us posted on how they do!

Neale

 

[0x0000ff]

Hello Hello

It's been exactly one month since the birth of these fry.

This is them at less then 1 hour old, miniature duckweed leaves give a good size comparison

the day after, I found 2 more in the tank they were born in, bringing the total to 14 fry

One of the fry was ... rounder .. then the others, and wasn't able to swim properly. It was dead by the end of day 3.

Now, one month later they're all still alive, but it's clear one of them is ah, defective.

The tank they're in is made of thick perspex making it very hard to photograph them at about 16-20mm in length.

They have been a translucent, generic "fish" colour up until the last week, now they have started taking on the metallic sheen of their parents.

silhouette (sp?) of the defective one:

heres some pics i managed to snap of some of the others

imageshack has been slow lately, let me know if the pics don't work and i'll rehost them.


They have been greedily eating prepared foods, crushed pellets and common ants

they have refused to eat grindal worms, which is strange as every other baby fish (including halfbeaks) i've had has loved them more then any other food.

they haven't eaten daphnia very readily either

when first born they ate baby brine shrimp, but I stopped feeding it to them as soon as they started taking fry pellets as brine shrimp are too hard and expensive.


That's all I can think of right now!

 

[nmonks]

Looking good!

You are right about them being tricky to feed. Sometimes, a batch will take daphnia straight away, another time, they go for flake. The batch I have right now only like one brand of flake and ignore another. It's all pretty random, so as you're doing, the best thing is offer a little of everything and see what they go for.

Funnily enough I had one with the exact same spine deformation, so I don't think it is rare. She lived for around 2-3 months, and then died for no obvious reason. It's up to you whether you keep it alive or not, but certainly avoid breeding from it.

Keep us posted with how things progress,

Neale

 

[helterskelter]

I've only breed these once many years ago, but my friend breed then on a regular bases.

He's just posted a small article on the link below.

http/www.livingfish.co.uk/forum/article.asp?art=856