|
|
FAQs about Jawfishes, Family Opistognathidae Reproduction
Related Articles: Jawfishes,
Related FAQs: Jawfishes 1,
Jawfishes 2, Blue-Spotted Jawfish,
Pearly Jawfish, &
Jawfish Identification,
Jawfish Behavior, Jawfish
Compatibility, Jawfish Selection,
Jawfish Systems, Jawfish Feeding,
Jawfish Disease, Best not to have
other fishes present. | 
|
Opistognathus aurifrons breeding... sys., fdg...
reference 11/9/09
About 10 months ago I purchased a mated pair of pearly Jawfish
Opistognathus aurifrons to attempt breeding.
They finally started breeding in September.
My setup is as follows:
29g AGA tank drilled w/ overflow connected to a 45g sump, that also runs a 90g display and a 14g frag.
Current USA 48w T5 HO fixture
5.5" DSB, with liverock placed in the substrate to prop up the
liverock on top, excellent for their burrowing.
Temp 76.5-77.5,maintained by 1/3HP chiller on the 90.
pH 8.10 minimum, maintained by Kalk Reactor/Doser in the sump (highest
I have ever seen in the combined system is maybe 8.3)
Sump has a ~20g refugium with 8" DSB, tons of Chaeto, and LR w/ a 80w
PC light, helping to keep the water chemistry stable.
12/12 Light Cycle
Here is the rundown of my larvae batch attempts so far.
Larvae batch #1
Male released late Sept. Died by day 4-5, probably due to lack of
sufficient food, because the culture of rotifers I had (S-type) were
stored to long, so the culture was not very thick.
Larvae batch #2
Eggs noticed: Oct 7
Released: Oct 22 (possibly an newer batch than the one noticed on Oct
7, 15 days incubation time is to long for this species)
This time I was better prepared. I had a L-strain rotifer culture to
work with for this batch, as I couldn't get anymore S-strain on short
notice, so I crossed my fingers.
Day 1 - Once they hatched, I moved them to a 5.5g AGA tank (blacked
out sides), with a 25w heater set on 75, and foam filter. The foam
filter is the yellow ring kind you get from Florida Aqua farms, the
ones with a yellow doughnut of foam, around a central stalk, which I
slowly had bubbling, maybe 1-2 a second. I did 50% daily Water Changes
on the larval tank.
Day 2 - Mortality on seemed to be a lot, but I thought the bulk was
probably just some of the enviable, plus some of the weaker larvae.
Probably about 50 of the 200 or so larvae needed to be siphoned out.
Days 3-5 - Everything seemed to be going better. I fed 1/3 of my live
culture a day, plus some frozen rotifers, because my culture was kind
of small. Less mortality, maybe 20 a day here, but still a lot. I kind
of figured that they were eating the Rotifers, because most of the
batch was still alive. On day 4 I also noticed the pH was 7.8 and the
Ammonia was about .5,
<Need to address this. Is very toxic>
and then after a 50% WC, on Day 5, the Ammonia
level was 1.0.
<Deadly>
I siphoned out all the rotifers from the bottom,
probably mostly leftover frozen I had been feeding, and started doing
larger water changes, by slowly trickling the water from my main tank
into the larval tank, probably about 80% water changes at this point.
(Still a fair bit left alive at this point, even during the 1.0
Ammonia level)
Days 6-8 - On these days I continued larger water changes to keep the
Ammonia level down, keeping it at or below .25, but still kept having
a good bit of mortality, and I noticed something funny about some of
the dead larvae. They were pink. For some reason some of the larvae
that died and ended up in the bottom of the tank had pink spreading
out from them on the tank bottom. (More on this later).
Days 9-10 - By Day 9 I only had about 7 left, and I kept a good eye on
water chemistry, feeding less, and doing less water changing, as it
wasn't necessary, but on Day 10 I only had two larvae left, and on D11
I had none. So batch #2 was down.
Larvae Batch #3
Eggs noticed: ~10/29?
Released: 11/3
For this batch, my L-type rotifer culture was really depleted, and the
little bit of S/SS-type I managed to save from my first wasn't large
enough yet to be used for feeding either. I decided to try feeding the
frozen rotifers, which were Brachionus spp., just like my cultures,
because I thought the larvae were eating the frozen along with the
live in Batch #2.
Day 1 - At hatch, the larvae, which appeared to be about 250+ this
time, were transferred to the larval tank (AGA 5.5, blacked out sides)
with the same heater/foam filter as Batch #2, but I decided to raise
the temp a bit, to 77-78F. Some time over the course of the first 24h,
I noticed what I think may be the cause for some of the larvae to die
and possibly cause the pink decay on some of the dead. They appeared
to be attempting to eat the foam filter! I noticed some would make
"jabs" at it, and back away twitching like they were trying to take
bites out of the bright yellow foam ring. I really think they were
nipping at it and trying to tear pieces of the foam away. I think this
may be why some of them died and had a bright pink area around them on
the bottom glass. Could this be the foam they swallowed being broken
down?
<Possibly... these fry may have taken the foam for food, or seen food
organisms w/in it>
Day 2-3 - I removed the foam filter, and replaced it with just a
airstone, set to make small bubbles, and set fairly low also. I made
water changes daily, about 50% a day to keep the Ammonia as low as
possible, but by the end of Day 3, I had 100% mortality again. To note
the Ammonia level, without the foam filter in there, it kept rising,
so it stayed around .5, even after doing massive water changes,
probably due to the use of frozen rotifers as food.
<Yes, and the lack of biofiltration>
Larvae Batch #4
So on 11/6, my male had a new batch of eggs in his mouth again. I am
currently awaiting this batch, but would like to get some advice here
so maybe I can finally succeed in bringing a clutch to meta, and
hopefully have some juveniles to give some of my friends. What do you
guys think?
(1) Are SS/S or L-type rotifers good food for this species? I am not
so sure they are. Has anyone done a gut dissection to see if rotifers
are there?
<I would be culturing copepods for follow up food... Please see Frank
Hoff's works, consider Algagen as a source of Calanoids:
http://algagen.com/home.htm... I would also have/leave some live
phytoplankton present with the Brachionus... and leave some light on
24/7
to help/keep the young feeding>
(2) Why would they die and then some have what looks like hot pink
blobs around them when decaying (keep in mind its just some, not all)?
I think its the ones eating the sponge filter that look like this.
<Death likely due to water quality issues... Any ammonia presence is
very
bad. I encourage you to either make DIY or buy (see Aquatic EcoSystems
site
e.g.) a culture vessel w/ overflow screening to do filtration in a
companion, tied-in tank. The color could be just decomposers,
decomposition>
(3) What about the temp for the larval tank? I think 75F might have
been a bit low, so I am thinking 78F is a better setting, more
reflective of the Caribbean temperatures this species is used to.
<Either should do. I like the lower temp. to give the young more margin
for
growth w/o speeding up their metabolism>
(4) What are acceptable Ammonia levels for larval tanks?
<0.0>
(5) Are 50%-80% Water Changes to <too> much? Even when the replacement
water
comes from the main tank to keep with chemistry, and is trickled in
over the course of 1-2hrs?
<... better to drip/trickle new water in... treat it and recycle it back
in...>
(6) Would a bigger larval tank be better? Wouldn't a larger tank make
it harder for the larvae to catch food?
<Mmm, better for rearing, but not necessary... harder in some ways to
keep
sufficient food densities>
(7) Should I try to get Acartia tonsa copepods as a food source?
<One species, possibility... I'd also suggest Pseudodiaptomus pelagicus>
(8) How much should I "bubble" the larval tank? I read large bubbles
were bad, so I tried to use a smaller airstone, with smaller bubbles,
and on a low setting.
<Not too fine... 1 mm. diameter is about right. Glass airstones are far
superior. Again, shop Aquatic EcoSystems: http://www.aquaticeco.com/>
(9) Is a foam filter a bad idea? It seems to be, since they appear to
be eating it! Other methods for circulation/filtration?
<I would use an "open box filter" w/ Dacron polyester media myself...
though I am VERY partial to the HydroSponge line>
Sorry for such a long winded email, but I wanted to be thorough!
Thanks,
Landon
<Thank you for sharing Landon. Please do report back your further
experiences, findings. Bob Fenner>
Re: Opistognathus aurifrons breeding 11/9/09
Hi Bob,
Thanks for the speedy reply. I appreciate the help. I have already found
the glass airstone on AquaticEcoSystems, and sent an email to Algagen
about Calanoids.
<Ah, good>
My question about your responses now are:
(1) You said that "I would also have/leave some live phytoplankton
present with the Brachionus... and leave some light on 24/7 to help/
keep the young feeding", by this I assume you mean keep a light on the
rotifers?
<Sorry re the lack of clarity here. I mean/t to say to leave the lights
on continuously (though not bright) on the culture vessel with the
Jawfishes (and algae and rotifers)>
I thought this would have negative effects on the rotifer culture water
quality.
(2) You mentioned an "open box filter" setup, by this I assume you mean
just a regular HOB filter, with Dacron over the intake pipe to keep
larvae out? or Dacron in the filter chamber?
<Actually, an in-tank, air-driven box filter... let me see if I can find
a graphic on the Net:
http://www.csupomona.edu/~jskoga/Aquariums/Cornerfilter.html>
(3) You also mentioned a larval culture vessel with overflow screening.
I checked Aquatic Eco and didn't seem to find one for larval fish, most
of their vessels were either for rotifers/brine/etc, or were huge
commercial applications. Do you have a more specific example?
<Mmm, here:
http://www.thefishsite.com/articles/contents/05-06UMissCultureFig1.gif>
(4) What are some good filter media or overflow screening materials?
Any specific brands/types? I would assume anything such as 53um
(micrometer) or so sieve material would get clogged to easily. Where
could one purchase such fine screen material in the micrometer range?
<... this is too much to answer well here. Again, you'd do well to
invest some time, reading in the field. Chemically inert screening for
the purpose or adaptable for this application is available in many
formats. Most anything that is chemically inert.>
One thing I considered was a 10 or 20 gallon tank, plumbed into my main
system, using some sort of filter/screen material over the PVC overflow
pipe to keep larvae from going into the sump.
<Yes!>
This should
stabilize water quality/temp/chemistry should it not? I would guess the
filter/screen material would have to be smaller than 150um or so
wouldn't it?
<Mmm, maybe for small larvae as in Opistognathids, yes>
Thanks for the advice on the Hydrosponge line, they look great, I must
order some of those also, and thanks again for any input. If I have any
success I will surely post the results to help others.
Landon
<Thank you Landon. I would also proffer it to the Breeder's Registry and
MOFIB.com. BobF>
A source for Brachionus rotundiformis for feeding pearly
Jawfish larvae.
- 10/06/2009
Hi,
I have been searching for a source for Brachionus rotundiformis, the S-
Type rotifer strain. All of the online vendors seem to only sell the
L-Type strain (Brachionus plicatilis). Do you happen to know a place
I could order the S/SS strain from?
<Mmm, yes:
http://www.seahorsesource.com/cgi-bin/shop/search.cgi?&category=Foods-Live>
I am using them to feed Opistognathus aurifrons (pearly/yellowheaded
Jawfish) larvae. Also, would you suggest any particular enrichment to
feed the rotifers?
<Do ask the folks at Seahorsesource re... I would do a bit more looking
about in the scientific literature if this is an important project>
I lost my first batch of larvae either to fact that L type rotifers are
to big for them to eat, lack of nutritional value, or rotifer culture
contamination/crash.
Thanks,
Landon
<Do keep good records... consider making your results, investigations
more widely known. Bob Fenner>
Wife swapping Jawfish 10/14/08
Hey Crew,
So there
are some strange goings on in my biotope. I lost one of my female Pearly
Jawfish 2 weeks ago (I believe due to her mate not letting her out of
the burrow to feed). I now have 1 female and 3 males, and the female is
in a different burrow every few hours! She's pretty assertive, nipping
at the males tails if they try to keep her penned in, as she like to be
roving the entire aquarium as much as possible.
I've been looking,
but have yet to find anything about this sort of behavior, more that
they are pretty monogamous fish as long as their mate is alive. Ever
heard of this sort of "wife swapping"/Jawfish Stud farm sort of thing?
-Darby
<Hello Darby. Jawfish (Opistognathidae) can be polygamous in
the wild, given the chance at least, although usually described as
monogamous fish. Do see "Monogamy in marine fishes", Whiteman and Cote
2004 for an overall review of monogamy/polygamy in small marine fish.
It's actually pretty common for fish to switch between breeding modes
depending on the circumstances, and arguably happens even supposedly
monogamous animals such as humans! If one or other partner can get away
with "spreading its genes", it will. Since the female doesn't brood the
eggs, the male does, she can get away with (and evolution will likely
favour) mating with multiple males. It's an insurance policy that means
that even if some of her mates are hopeless fathers, at least some of
them will be better. If she (literally!) puts all her eggs in one basket
-- i.e., mates with just one male -- she's gambling everything on that
male being a skilful father. This behaviour is constrained by
environmental factors. For example, if both parents must work together
to defend the eggs/fry, each parent is less likely to philander. But
that isn't the case here, because male Jawfish have their own burrows
and incubate the eggs alone. Among cichlids, many species form
monogamous pairs in aquaria when forced to do so, but are polygamous in
the wild (Kribs are the classic example). So in your situation, you've
got a tank where the female is able to choose from multiple males, and
is taking full advantage of the situation. Cheers, Neale.>
Pairing Blue Spot Jawfish 03/04/2008
I am writing to ask if it is
possible to have Blue spot jaws pair up? I purchased a small BSJ and
within a week found a larger specimen with a substantial size head. I
rolled the dice and hoped they would form a pair. Well, little BSJ went
fin to fin with large BSJ. The little one escaped alive minus a hunk of
his lip. Now each has started to settle on different ends of the tank,
and engage in stare downs. I have moved LR to create obstructions in
their sight paths. Is there any hope they will pair?
<<I Would guess
not. Keeping two Jawfish such as these does need a large amount of space
between them, and i imagine in your tank, they are literally at opposite
ends>>
or should I just be happy I don't have little bits of blue and
yellow very pricey fish flesh floating about?
<<Yes, be happy>>
Just to add, they are alone in a species only 30 g tank. LR and deep
mixed sand bed. Just hermits and cleaner crew. Both are eating fine,
even the one with the missing lip.
<<To be honest, i would not of
recommended two of these in a tank so small>>
This is my first
attempt at BSJ. I have breeding pairs of pearly jaws in 2 other tanks.
But these flashy fellas seem a very different beast, than their
Caribbean cousins.
<<Indeed. More reading for you here
http://www.wetwebmedia.com/jawfishe.htm>>
Thanks, Beth
<<Thanks
for the questions. A Nixon>>
Weaning a genderless tunnel happy Jawfish. Fdg., sys., repro.
2/17/08
Hello all,
I introduced a Bluespotted Jawfish
(photo attached), nearly a week ago now. Unable to quarantine at
home (a fifth tank might get me murdered by my better half), I had
my buddy at the shop hold him for three long weeks. I had to remove
an ornery (and quite large) Mithrax crab, but the Jawfish settled in
quickly, building a network of caves within mere hours. I've been
feeding frozen mysis, brine, and formula one using a pipette, which
the fish takes to like a baby bottle. Now here in lies my first
silly question: Am I going to cause the fish to develop a dependence
on food coming directly to it?
<Mmm, doubtful... I have observed
and even collected this Opistognathid (at the tip of Baja)... and
seen it in exhibits for years (mainly in home town San Diego's Birch
Aquarium)... and it doesn't seem to lose its natural "hunting
behavior">
Because, as it is, the Jawfish only gets to eat once
per day, unless I were able to convince my girlfriend to spend the
time each morning to nurse it on the pipette, or the Jawfish decides
to join the rest of the group in swimming after food that's just
dropped into the water.
<Mmm, do think on the addition of a
plankton generating refugium here... much to be gained>
Secondly,
I did search the site on sexing the Bluespots, with no definitive
results. So, is there any good way to determine sex of these little
guys (and girls)?
<Not as far as I'm aware... until they
actually spawn (males are mouthbrooders)>
Finally, the wonderful
mountains of sand. I was planning on adding a bit more sand; the
middle to the back of the 125 gal. tank is 3-5 inches of mostly
sugar-fine grade sand, the front...maybe an inch, and now due to
some of the tunnel construction that has occurred I'm concerned that
if the Jawfish removes too much sand from the foundation of a large
rock bad things could happen.
<All large solid objects need to
originate on solid bottom... the bits on top neatly, stably placed
atop this...>
So, as I understand it, these guys like varying
grades of sand. But, should I keep with the sugar-fine grade, or did
NNR go out the window when the Jawfish started tunneling?
<To a
large extent, yes>
I just want to make sure this fish is as happy
as a fish can be inside a glass box. Any knowledge, insight, or
criticism is greatly appreciated.
<I would mix in some larger
grade, even rubble of varying size... makes all tunnels more stable
and is a hoot to see it all get moved about. Cheers, Bob Fenner>
-Cheers-
Jules (Portland, OR) | 
|
Tiger Jawfish Keeps laying eggs, and unidentified coral 01/28/2008
Hi all,
<<Hello, Andrew today>>
It's been a while since I wrote
last. I have a 95 wave tank with 48" metal halides (by orbit) it's also
got actinics and moonlights. Everything is on a timer. I do regular
water changes, about 10-20% every week. I supplement the tank with the
following;
Essential Elements (5 ml/week)
Liquid Calcium (2
tsp/day)
Microvert (5 tsp/week)
Tech M (20 ml/week)
Phytoplankton (10-15 ml/week)
<<Sounds good>>
About a year ago I
purchased two Tiger Jawfish about two months apart. Initially they had a
couple spats but got over themselves. After I moved and re-arranged the
tank they started living with each other. Now the female stays plump and
the male has a new batch of eggs in his mouth every couple of weeks. I
have a brine shrimp tank where I hatch them but I haven't seen any baby
jaws to feed. I use a turkey baster to feed my corals, I used that to
spray some of the hatched brine shrimp into the Jawfish den. It's been
about 3 months since it's started and I was hoping you had some advice
about raising them. I'm moving in the next month so I don't have a lot
of time. I doubt they'll start breeding again after I move.
<<Your
best bet to attempt to raise them is to move them to a separate aquarium
as they will more than likely become a nice meal for other inhabitants>>
I was also wondering what this coral is (only photo of just a coral
attached) It's about the size of a volley ball and it seems happiest
about a foot from the top of the tank.
<<The coral is a Favites SP
closed brain LPS coral. Looks bleached with a severe loss of colour.
Please read more here http://www.wetwebmedia.com/faviidae2.htm >>
If
I need to list what's in my tank I can. I included a couple photos of
where the Jawfish den is (just under the rose anemone)
Thanks ahead
of time! Matt
<<Thanks for the questions. A Nixon>> |
.JPG)  |
Yellowhead Jawfish stkg. 12/27/07
Dear Crew,
Thank you for all the help you have I given me in the
past. You don't know how much you have helped me. Unfortunately a new
problem arises. I have been interested in Opistognathus Aurifrons for
some time now and have been planning to convert my 55 gallon freshwater
tank into a saltwater tank for the soul purpose of keeping these
Jawfish. My question is if I kept nothing but Jawfish and some liverock
in this tank could I fit four?
<Mmm, possibly... but all would be
happier/better with just two or three...>
The reason I would like
four is because I would Like to obtain a pair for breeding purposes. Any
suggestions?
Thanks,
Tuscan Thompson
<Take a bit of time
reading accounts of Jawfish spawning, aquaculture... Maybe start at the
Breeders Registry (.com). Bob Fenner>
Jawfish and Pod
QT! 4/27/07
You have a fantastic site and very worthy of
the days (yes, days) I've spent reading during the past couple months
since starting a 55 gallon SW tank.
<Thank you.>
My
setup is: 5-7" DSB, 60# LR, 360gph canister (bio-balls removed),
<Good…>
two powerheads, SeaClone 100 skimmer,
<not my first
choice, or second. third…but better than nothing.>
130w PC 50/50
actinic & 10k daylight; and water data is: PH 8.2; Ammonia & Nitrite 0;
Nitrate 7.5; Salinity 1.025; Alk 13dKh & Calcium 375. Inhabitants
include 2 Percula clowns, 3 Chromis, 2 damsels (going back to the store
as soon as I catch them),
<Also Good.>
2 BTAs,
<Clones of
each other I hope?>
several hermit crabs, feather dusters, various
snails, mushrooms, Zoas & a couple leather frags. All seem to be doing
well, better now since I caught & took 2 very ornery damsels back to the
store.
<Sounds functional.>
I have a 10 gallon quarantine tank
that has sand and shells on the bottom for two Jawfish I just ordered.
<Neat.>
I have wanted these since I started the tank; also the main
reason for the DSB in the display, although after research here, the DSB
is worth much more than just a substrate for the Jawfish!
<Yes.>
A couple of quick questions on the Jawfish - are they
hermaphroditic?
<As far as I know, they
aren’t. Breeding behavior is different depending on the species. You
can usually distinguish the male of a pair during mating events by their
more distinguished markings and color. To my knowledge there have been
a few successful breeding reports but almost all seen in the trade are
still wild caught.>
I'm guessing that they are not, but was curious
& haven't been able to locate that specific info. And I understand
that the Jawfish need some shells for structure of their burrows –
<…Don’t count out vanity,,,, yes fish can be arrogant too.>
do I
just put in a couple handfuls of crushed shells in a few places on top
of the sand where I would prefer that they burrow?
<Just place them
randomly around the tank, they will put them where they want them…and
may occasionally steal shells from each other as well….which as long as
no one gets hurt is actually fin to watch.>
I also ordered a group
of copepods, and am wondering about a quarantine procedure for them.
<Most people forgo it, but there is no “standardized” way to do it
really…>
I'm trying to go forward with the "quarantine everything"
adage,
<Good!>
but when I previously purchased some copepods for
the display tank, the instructions were to add the entire contents of
the bag directly to the tank, water and all (which I did with no ill
effects).
<You don’t mention which company you are
getting them from, but typically the reputable folks who market these
are very meticulous with their products. Keeping the strains
pure….literally down to a “science”, hehehe. There aren’t (again
typically) any pathogens or micro-organisms that would be a threat to
your fish.>
The new copepods are planned for the 20 gallon refugium
I am setting up, which is not attached to the display tank yet.
<Perfect, if the fuge is offline, go ahead and add the ‘pods directly to
the fuge, and wait a week or two before plumbing it inline….if you have
the space/ability to do so.>
I plan to put refugium mud as a
substrate covered with crushed coral, with red mangroves for nutrient
export.
<Mangroves are rather poor in comparison to other organisms
when it comes to nutrient export, read this by Mr. Calfo:
http://reefkeeping.com/issues/2004-12/ac/feature/index.htm .>
I
have planned on hooking up the refugium to the display tank as soon as I
get it put together in order to let the display tank cycle it. I
understand (from reading here) that there are different opinions about
whether the refugium should be cycled separately, but since I didn't
plan to add any bioload right away, I figured it would be okay to add
the refugium to the display as soon as it is set up.
<I
did this, had to compensate with extra water changes. It should also be
noted I precured the rock in a separate container though.>
However,
if I need to quarantine the pods, I would need to do that in the
refugium area before I hook to the main tank, and probably before adding
the substrate, right?
<Yes, as I mentioned above that
would be a good way to go……it will also give the pods sometime alone
(without being preyed on) to populate the refugium.>
The big
question is: Do I need to quarantine the copepods,
<Probably not,
but it wouldn’t hurt.>
& if so, what is the procedure?
<See
above.>
Thanks for all your help.
<Anytime.>
Lillian
<Adam J.> Question about male Jawfish 2/12/07
Dear Sir,
French journalist for the magazine "ça m'intéresse", I'm
searching data about gold-specs Jawfish. So, would you kindly please
help me ?
Here is the photo I have to comment :
http://www.acclaimimages.com/_gallery/_print_pages/0462-0701-2210-4201.html
> Is it Opistognathus gilberti ?
<Mmm, no... O. gilberti is found
only in the tropical West Atlantic... this fish is in Mabul, Malaysia...
I have photographed it in various places in Indonesia... The species is
undescribed as yet as far as I'm aware>
My questions are about eggs
:
> Why do the male incubate eggs in the mouth ?
<Mmm, likely a
useful species survival technique... though this family and the
Apogonids (Cardinalfishes) are the only marine fish families to employ
such mouthbrooding behavior)... Much more possibility of
success/survival with this technique than production of many more
gametes, dispersal to the environment...>
How long ? How many eggs ?
<A few weeks, hundreds...>
He never "eat" one of them ? What about
the female ?
<Not likely, and no>
> Something special or
surprising fact about those eggs that could interest the readers ?
<Likely all sorts...>
I thank you very much,
Bests regards,
Adeline Colonat
Magazine "ça m'intéresse"
<Robare Fenner>
Dusky Jawfish eggs 8/3/05
I have had 2 dusky Jawfish for a
year and now I notice 1 of them (the male) has a mouthful of eggs. Have
not noticed them before, but he has turned darker on his head. Anyway,
to assure that some, if not all of these eggs have a chance in my reef
tank, I am asking you for suggestions. I have a Sailfin tang, a blue
tang, a coral beauty, a niger trigger,2 percula clowns, 2 green Chromis,
a fairy wrasse, a psychedelic mandarin ,a cleaner shrimp and a
hitchhiker crab; some of which would love to get there little jaws
around some small live meals. What is the best way to raise some
Jawfish in captivity?
Dr. Ron Widen
<Really need to be moved...
via the male mouthbrooding parent, to another system to avoid predation,
and foods cultured for... Please read here:
http://www.wetwebmedia.com/jawfishe.htm
and the Related FAQs
file linked above, the references cited... Bob Fenner>
Jaw
Fish Breeding
Hi Bob,
<Anthony Calfo, here in your service>
As many others have said, the Conscientious Marine Aquarist, was the
first in our marine library. It gave us a good start, and continues to
answer our questions along with WetWebMedia. Thanks!
<an important
and must-have reference, indeed!>
We have three yellow tail damsels
(Chrysiptera parasema) and two yellow head jaw fish (Opistognathus
aurifrons) in a 55 gallon tank with 6 inches of mixed substrate
(aragonite sand, crushed coral, and Aruba shells) and about 30# of Fiji
live rock. For external filtering we have a CPR backpack (OK) and an
Eheim 2026 canister (worth every penny).
Additionally there are some
sponges, several Aiptasia, and various worms that came with the rock and
for cleanup we have some janitors from GARF. (We also have a 75 gal
reef tank with a bunch of corals from GARF and a few fish.)
Today we
noticed one of the jaw fish was holding its mouth slightly open and
looking in we can see glistening beads. WOW! looks like we're pregnant!
<Wow! you have a mouth full of eggs too?! How exciting and
bizarre!...actually, Congratulations!. How wonderful.!>
We are
overflowing with questions about how to give the potential new arrivals
the best chance to survive. Any sage advice? I can't find much of
anything searching the web. We have your jaw fish bibliography, and will
try to find Young's book on breeding.
<yes, realistically...be
prepared that this first batch is not likely to survive in the community
tank with pumps, filters and predators... but do seriously consider a
dedicated species-specific tank for breeding. Secondly, get set up with
a live food culturing station promptly. Refer to Moe's marine handbook
"Beginner to Breeder" or the Marine Aquarium Reference" for basic food
culture advice. And do look up Florida Aqua Farms for algae, rotifer and
shrimp culturing supplies and handbooks (they even have a plankton
culturing manual)>
Following are a few observations that I have not
seen on the web:
When the brooder needs to eat or do burrow
maintenance he puts the eggs somewhere down in the burrow, does the
work, then picks up the eggs when done. Since this whole operation
can happen quite fast (a few seconds) the egg mass must be sort of
sticky.
From time to time in the past (while in quarantine and when
first introduced) we would see the two sharing a burrow but lately they
seem to stay separate. The burrows are about 8 inches apart along the
edge of a pile of rock. At this point there is no evidence that these
tunnels are connected. In quarantine, the substrate was not very deep so
they had connected tunnels with several openings under a large piece of
live rock. When first introduced to the 55 gallon tank we expected they
would take a while to acclimate but they seemed to be right at home,
maybe because we also brought in the large chunk of live rock. It did
take a few weeks of excavating and trying different locations before
they settled in to their current locations. They sure can move a lot of
material around.
<yes...and very entertaining! have you noticed them
stealing shells from each other at night to cover their burrows...a
hoot!>
When the lights go out (sometimes a short time before lights
out) both jaw fish completely cover their burrows. This cover is so
complete there is no evidence that there was ever a hole there. After
the lights come on they remove the covers.
<ahah! I should have read
further...hehehe>
Have been looking for a way to tell the male from
the female and don't see anything except the brooding.
<difficult...but notice the enlarged folds of the buccal cavity (chin)
and broader skull>
Lee & Mary Powell
<please write a follow-up...
looking forward to future spawns! Anthony Calfo> Breeding
Pearly Jawfish
Hi Bob,
<cheers, friend from afar. Anthony
Calfo in your service whilst Bob travels>
I have a 200l tank with a
pair of Pearly Jawfish in it. I have set this tank up solely for the
purpose of breeding the Jawfish.
<it is very exciting to hear an
aquarist with a proper system for fish breeding>
I live in South
Africa so we do not get the Jawfish here very often as flights are long
and the losses are great.
<understood... a fascinating fish indeed>
I have had the pair now for close on to a year and they have now started
breeding. The female will really swell with eggs (Clearly visible behind
the stomach). The female enters the males borough about 1Hr after
lights on and spends about 15 to 20min with the male. When appearing
again the male will be carrying eggs in his mouth. The eggs are white in
color and are about 1mm in diameter. The problem is that the male eats
the eggs after 1 to 3 days.
<this is not at all uncommon with many
young pairs... even the best suited mates often fail with the first
several to a dozen spawns>
I feed them once a day with a well varied
diet which includes live food. I keep feeding them while he is carrying
the eggs which he leaves in his borough to come and eat. Could the eggs
be infertile?
<quite possibly as they are a bit clumsy with each
other at first>
Should I try to recover the eggs from his hole when
he is eating and then try and agitate them with a small pump?
I
would wait to see after several more attempts before trying to rear
artificially>
Could this work as I have read that some people hatch
their Dottyback eggs in this manner?
<yes my friend, but it is a lot
of work and very tedious. Lets see if the natural parents don't evolve>
Any help would be appreciated. Tokkie.
<keep up the good work! With
kind regards, Anthony> Mixing Jawfish? 3/24/03
I would
be grateful for an opinion on Jawfish compatibility:
<easy one...
they are scary territorial>
Can more than one Blue-Spotted Jawfish
get along in and 80G tank?
<probably... seek females (smaller
head/jaw, buccal cavity)>
How about one Blue-Spotted and one
Yellow-Headed?
<not recommended... but a very tight cover on the tank
for all is... they are serious jumpers>
More than one Yellow-Headed?
<perhaps yes... 2... not more than 3 conspecifics. All need very deep
substrates too. Some say 12" ideally. Most all say 6" minimum>
What
about Dusky Jawfish--can they be kept more than one to a tank?
<indeed, not. Quite aggressive to each other.>
Thanks!
<best of
luck... do try to purchase a pair/trio from the same tank/dealer for
better chance of compatibility. Anthony> Sexing Jawfishes
2/6/04
Hi (love you're site!) I was wondering if you new how to
tell how to tell the difference of the Yellowheaded Jawfish.
<the
one that won't stop to ask for directions is the male...>
I couldn't
find it on your fish articles all it says is that it's hard to tell the
with the Yellowheaded Jawfish.
<true. Its not reliable, and best
done with a group to compare to. Males have larger skulls, thicker lips
and larger buccal cavities (chin-pouch so-to-speak). Rather like sexing
FW cichlids. Anthony> Breeding Jawfish
Dear Mr.
Fenner,
<John>
Recently, I noticed one of my Jawfish
carrying eggs in its mouth. I have read the FAQ's page discussing
Jawfish breeding but still have many questions. My questions are geared
toward the raising of the Yellowheaded Jawfish (Opistognathus aurifrons)
from eggs to larva to adults. Currently the pair is being housed in a 90
gallon display tank, with wet/dry filtration, powerheads, and a skimmer.
I Don't think the larva will survive the display tank but I've been
thinking of setting up a twenty gallon species tank, for the purpose of
breeding. I would appreciate any thoughts and recommendations on
equipment for this set-up.
<A twenty might do... you should
(quickly) read through Frank Hoff's works on food culture, start your
gear going for same... see Florida Aquafarm's site re>
Also, I have
no idea what the requirements for caring for and feeding the larva and
on to the fry (hoping they make it that far) should be. I would
appreciate any advice you can give me, and any references to web sites
or books where this may be discussed. Also, I was wondering if many
people have had success raising Jawfish to adulthood.
Thank you for
your time,
John
<There are a few protocols. Take a look on the
"Breeder's Registry"... Bob Fenner> Info. on Opistognathid
culture?
Hi,
<Hello there>
First off, I want to say that
this website is great! I've just stumbled across it while doing a search
for info. (which brings me to my question in a second...) and it is very
cool that you (Bob) and the other generous persons on this site are
providing all this information. :-)
<Welcome>
Ok -- on to my
question: Do you know where I could get information on rearing
techniques for Opistognathus sp.? I saw on your site that "some species
of Opistognathids have been bred and reared in captivity" and I was
wondering who or what organization I could contact to possibly get
details.
<Mmm, Frank Hoff's works, general searches on the Net, there
are some recent books... Do you read German?>
I recently completed my
Master's thesis project at a university on the East coast involving
finfish culture and I'm now on the West coast and getting ready to start
up some culturing of my own to possibly sell to LFS/warehouses in the
area.
<Ahh! There is much anecdotal (as opposed to more scientific)
information/observational work on Jawfish reproduction... but many
species have been cultured.... though the principal (aurifrons) is still
mostly wild-collected...>
Thanks in advance for any information or
advice you can give me.
Sincerely,
Kristin
<Will help you...
more... if you'd like, on return to the States (where ref. works are).
Bob Fenner, in Quito>
|
|
