Livebearing Halfbeaks in the home Aquarium

Keeping Common Livebearing Halfbeaks:

Two genus of Halfbeaks are commonly available to the
Freshwater Hobbyist, Dermogenys and Nomorhamphus,
I will treat each separately, first though an overview of there
Taxonomy and Biology,

Taxonomy:
Order: Beloniforms
Suborder: Exocoetoidei
Superfamily: Exocoetoidea
Family: Hemirhamphinae
Genera: Dermogenys
Hemirhamphdon
Nomorhamphus

Halfbeaks belong to same Order that contains, Flying fishes,
Needlefishes and The odd little Medakas (Ricefish),
Hemirhamphinae were considered to be in the Order,
Cyprinodontiforms (Killifish and Livebearers) this was seen
as largely erroneous and is not accepted by many,
Further reading on the subject:
Rosen, Donn E. and Parenti, Lynne R., ?Relationships of Oryzias,
and the groups of Atherinomorph fishes?, American Museum
Novitates, 2719, pp. 1-25 (1981)
Meyer, Manfred K., Wischnath, Lother and Foerster, Wolfgang,
Lebendgebarende Zeirfische- Arten der Welt, Mergus-verlag (1985)
(the best and most comprehensive Book on Halfbeaks, only
Available in German though, a Translation is in the works last
I heard)

Biology of Livebearing Halfbeaks,
By just looking at a Halfbeak you can tell these fish are well designed
for where they live and what they eat, Halfbeak are a surface dwelling fish,
and normally that is where they spend the majority of their time. Unlike
the Poecilia (guppies etc) the males do not have the familiar gonopodia
shaped anal fin, instead the anal fin is distinctive in having a Knee like
structure in the second ray of the fin then separates into two spines, the
skin between the third and forth ray have a pouch like structure,
These unique characteristics are only found in these fish, it is given the
designation andropodium by most.

Now that the easy part is done now we lead directly into the realm of
Hearsay, contradiction, and confusion, How to keep the little suckers
alive and how to Breed them with any amount of success,
I?ll be separating the two genus and dealing with each
on a genus wide basis, as care is identical for all species for the
most part, I?m leaving out the genus Hemirhamphodon, suckers are quite
rare and unless you really really look your not likely to find them,
( though I do know someone who has H. pogonoganthus, nice fish)

Dermogenys, The Wrestling Halfbeaks:
These are by far the most commonly available Halfbeak,
three common species are often seen, all look the same for the most part,
D. pusillus pusillus from Indonesia, D. p. siamensis from
Thailand (The most common of all) and D. p. sumatranus from
Sumatra and Borneo. Several other subspecies are claimed by
some texts, and often these subspecies will be raised to specific
level by some authors (E.g. D. siamensis, D, sumatranus, etc.),
to add to the mess several other species are known, none though
show up in the hobby as often as the D. pusillus sp. complex,
(which I will refer to from now on as Wrestling Halfbeak)

The Wrestling halfbeak reaches about two inches(6cm) for males,
and three and a half inches(8cm) for females,
Males can be told from the females by the characteristic andropodium,
and more colorful fins, Females are often much more bulky as well,
As the common name implies Males are quite aggressive toward one-
another and will fight for hours in some cases, usually though these
fights do not lead to injury, these fish do best in a species tank
by themselves, they do not fare well in a community tank.
Keeping these fish is not all that difficult with a reasonable amount
of space and good water quality and nutrition,
Tank should have a good amount of surface space, ?Breeder? type
tanks work very well, High and narrow tanks will not work,
For a trio of fish you need over 15 gallons for long-term care, Halfbeaks
do not like to be crowded,
water should have at least 1 teaspoon of aquarium or marine salt per gallon,
Frequent water changes are a necessity, these fish will not tolerate,
Dirty water and will quickly die in it, Temperature should be set at
75 F or higher up to 95 F
Feeding is not all that difficult they will accept Flake and freeze dried
foods, all sorts of frozen foods, and many live foods, at least that?s what
the books say and few people I know,
I my experience:
I had a hell of a time keeping them healthy or breeding without live
or frozen foods, they accepted other foods but would just waste away,
I feed them Fruitflies, live and frozen brine, frozen bloodworms,
Live and frozen daphnia, worms, ants, just about any food I could
catch or buy for them, Key to feeding them is feed them one at a time,
so you know they are eating,

Breeding Wrestling halfbeaks is quite easy just throw a male with
two females and bingo you get two big fat pregnant females, that?s
where easy ends, if your really lucky she will not prematurely abort
the fry outright, then six to eight weeks later
she does give birth and 90% of the fry die in
the span of a few hours or days, (or get eaten, if the mother is not well
fed,)

Not all livebearers are simple fish to breed, in fact, most are not once
you go past the fab” Hobby strain four” of, guppy, molly, platy, sword.

There are though some Guidelines and methods you can use to
increase your odds at getting fry and having them survive, this is
what masochistic frustration Lovers such as myself have learned,
1. Feed a lot of live foods and feed often, even to the point of having
a swarm of Daphnia in the tank at all times, this will greatly
improve your success rate.
2. Keep the temperature above 85 F, this tends to reduce the
premature aborting of the young.
3. Keep the water very very clean in the fry raising tank,
1/4th of the water Daily should be changed,
Feed the fry often with Baby brine, grindel worms, and
Daphnia, again having a swarm of Daphnia helps

I could go on about the 20 other ways of keeping Wrestling Halfbeaks,
but will spare you, enough should be covered above to get you started

Now for the second Genera:
Nomorhamphus, the Celebes Halfbeaks
The most commonly available species is N. liemi and its subspecies
N. liemi snijdersi, often though some of the oddball ones can be
found in shipments of them, five some other species are known,
and some are not yet described, Color variations exist depending
on the fishes origin, (there has been debate on whether some
of the currently described species really merit specific status,
until the taxonomists figure it out I?m sticking to the older names
according to Meyer et al Lebendgebarende Zierfische)

N. liemi and N. l. snijdersi can be deferred from each other from fin
color, N. liemi will have mostly red fins slightly edged in black,
N. l. snijdersi will have red fins but with broad black bands on the
edge, (aside from this you have to go by merits and that?s a pain on
a live fish swimming around a tank)

Nomorhamphus are quite a stunning fish and they get quite large,
Females can reach lengths to 4 inches, males are smaller growing to
about 3 ? inches, Males again have the characteristic andropodium,
Both sexes are fairly colorful the male being more intense, older males
grow a fleshy black recurved appendage on the tip of the lower jaw,

Care is much the same as Wrestling halfbeaks with some distinct
differences, Nomorhamphus are not a brackish water fish and prefer
soft, slightly acidic water, a good range to keep them in would be
6.5 to 7.0 pH with soft or medium hardness,
Water quality again though should be kept very high, with frequent
water changes being a necessity, Aquaria should not be under 20 gallons
for one trio of fish, Males of this genus are not all that territorial, and do
not exhibit the aggression toward other males that Dermogenys does,
Feeding is non-problematic and they will eat all the foods listed for
Dermogenys, they also will eat any small fish they can catch in
addition, I have not had any problem maintaining this fish with a diet
of mostly prepared foods, Breeding proved to be difficult with out live
foods,
these fish particularly enjoy fruitflies and small crickets and are quite
amusing to watch stalking them,

Breeding is problematic and many of the same problems with
Dermogenys are problems in Nomorhamphus, Premature birth
being the top problem, Lots of live and frozen foods seems to help
some in this area,
these also are not very prolific fish with an
average brood is about 10 fry, the fry are born at about one inch,
unlike Dermogenys though, the fry do not seem as delicate and grow
quickly if well feed.

I highly recommend Nomorhamphus over Dermogenys for beginners
new to this type of fish,