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FAQs on the Cyprinodontids, Pupfishes et al.

Related Articles: Cyprinodontid Fishes, Cyprinodontiform Fishes, Killifishes: Part 1 by Dr. Robert J. Goldstein, Killifishes, Part II- The Nothobranchius Family  by Robert J. Goldstein, Ph.D

Related FAQs: Aplocheilid Fishes, Killifishes, Aplocheilids, Rivuline Fishes

Fish I.D. Help   10/6/10
Dear Crew,
During a recent visit to our local zoo we came across this particular fish in a saltwater display (yes I am sure it was saltwater). I have been scouring the internet in an attempt to find some, as they quite interesting
and I enjoy them. I thought perhaps they might make a neat addition to my 125g tank. I have to say though, it appears more freshwater than salt, given it was only about 3" in length and, in my opinion has rather large scales comparative to its body size. Seems to me most of the smaller fish offered in the trade are more "smooth skinned" in appearance, with less defined scales, though this could be a juvenile I suppose. I am by no means any type of marine biologist, and it has merely been a humble observation
of mine in the local shops I frequent, and the books I have read. Any help with an i.d. / possible lead on where to obtain some would be greatly appreciated. Thanks crew!!
<Hello Justin. This looks like Cyprinodon variegatus, the Sheepshead Minnow, one of the American non-annual killifish known as Pupfish. It's distributed across a very wide area along the coastline of the Americas from Massachusetts down to Venezuela. Although sometimes found in freshwater, it is primarily an inhabitant of brackish and saltwater canals, swamps and lagoons. It is famously tolerant of high salinity, including hypersaline conditions up to twice the salinity of normal seawater. In the wild it is commonly associated with Fundulus spp. killifish as well as Poecilia latipinna, all of them being found in brackish to normal marine habitats rather than freshwater habitats. Maintenance is best at a salinity at least one-quarter that of normal marine conditions, i.e., about SG 1.005. It can be kept in freshwater, but it tends to be less easily kept that way and more susceptible to disease. Water temperature should be room temperature or slightly warmer, up to about 25 C/77 F. Males are extremely aggressive towards one another, but otherwise the species generally ignores dissimilar fish. The specimen in your photo is a male, notable for its blue colouration that becomes especially intense when spawning. Females are more
green-brown. Like other Pupfish, this species is an omnivore that eats both algae and small invertebrates. Unfortunately this species is rarely offered in the trade. You may be able to obtain them through a national killifish association, or more easily, through a biological supply house. Although I've never used them and so can't recommend them from experience, biological suppliers Sachs Systems Aquaculture for example offers 4 of these fish for $25. That perhaps gives you some idea of the sort of place you could get them from and what it would cost. Within the aquarium hobby the Florida Flagfish (Jordanella floridae) is the only Pupfish routinely sold. Basic care is similar though it is a freshwater to slightly brackish water fish, and unlike Cyprinodon variegatus, Jordanella floridae is generally more peaceful and both sexes are nicely coloured. Cheers, Neale.>

Re: Betta temperature, and  10/2/10
Alas, I have no basement, but fortunately the temperature spike we experienced was only due to a bad blower motor on the air conditioner, not a regular occurrence.
<Oh, I see.>
Desert goby looks like a fun option. I may try to locate some to keep in an unheated tank. They are not on the Arizona Fish and Game restricted species list, so it's only a question of finding some.
<Arizona does of course have some fantastic desert fish of its own, including various Pupfish species like the Devil's Hole pupfish, Cyprinodon diabolis. But I fear many of these are threatened with extinction in the wild, so may or may not be suitable choices for home aquaria. You might ask around the fish clubs or local universities to find out if there are captive populations available from which you might you take a few. The irony with desert fish generally is that as species they're usually very hardy and breed extremely rapidly, but their habitats are being taken away from them, and even the toughest fish can't cope with a bulldozer flattening their habitat or removal of local water courses that cause their ponds to dry up completely. That we have fish that live in deserts should be the sort of thing we celebrate as a sign of how amazing Nature can be'¦ and yet they're amongst the least familiar and least protected animals on the planet.>
I saw you have a goby article in the November issue TFH. I looking forward to reading it.
<Hope you enjoy it. The Desert Goby is featured in there, I think as my #1 Goby!>
Regarding the small planted tank, I added some Hydrocotyle sibthripoides, a crown tail Betta, and two Amano shrimp. All seem very happy in their new home. (If I tell Bob F that I did not buy the Betta in a cup of blue water, he will know where in phoenix I bought them.)
<Cheers indeed, Neale.>
Re: Betta temperature, now...  10/5/10

Cyprinodon diabolis appears to be extremely endangered, with one source (Virginia Tech dated 2006) stating only 40 wild specimens remaining.
<Very sad.>
I'm guessing they might be a bit hard to come by, but I will definitely keep my eyes open for them.
<Good luck. Even if this species isn't available, other Southwestern killifish species might be. But honestly, I don't know. There is presumably an American killifish association or club, and they may be able to share
with you information on these species.>
I've wanted to keep Endler's livebearers simply to help keep them around.
Devils Hole Pupfish might be another one if I can find any captive population.
<Indeed. There are several aquarium species that no longer exist in the wild. I've got Ameca splendens here at home, a nifty if aggressive livebearer.>
<Cheers, Neale.>
For Neale (Cyprinodon of Nevada)  10/8/10

Thought you might find this of interest.
<Interesting. Does sound as if there are some captive populations, which is good to know. Fascinating fish. Sadly, the European killifish aren't in much better shape thanks to the same intense pressures on water and real estate in sunny but dry parts of the world. Do research the Desert Fishes Council, which I suspect you'll find publishes some interesting stuff.
Cheers, Neale.>

Florida flag fish in with chicklids  7/10/10
Hi there,
We have two florida flag fish
<A subtropical fish.>
in a 50- gallon tank with chicklids
<Cichlid, as in "sick lid"...>
we added a couple of parrot chicklids tonight and one of the flag fish keeps pushing the one parrot fish around
<Yes, it's what they do.>
...doesn't seem to be nipping at them just rubbing up against and almost like herding it into other areas or against the tank...Why is this?
<The sarcastic answer is "because you shouldn't be keeping them together"!
What I mean by that is they have no overlap at all in terms of requirements and behaviour. Florida Flagfish need subtropical conditions, 18 C/64 F is about the ideal, and are territorial and potentially fin-nippers. They work
best on their own or with fast-moving cool water fish, Swordtails or Rosy Barbs for example. Parrot Cichlids are of course hybrids, and deformed, handicapped ones at that. The people who bred them didn't give any thought at all to the well-being of these cichlids, and consequently while their brains tell them they're territorial, semi-aggressive fish, their bodies just can't handle that kind of life. As we say in England, "all mouth and no trousers" if that makes any sense to you. Parrot Cichlids are an easy target for nippy fish, and mustn't be kept with them. Bottom line, these two fish need to be separated. Cheers, Neale.>

Re: Florida flag fish in with chicklids   7/11/10
Thank you so much for your help :-)
we will separate them asap :-)
<Cool. Glad to help. Cheers, Neale.>

Possible fin-nipper? - 06/27/07 Well.... Along with the Rainbow fish, I added 1 American Flagfish (male), I have a female on order. I did read that they can be territorial, but I've watched him interact with the other fish, and while he will chase them away from his preferred location, there's no nipping and it seems quite harmless. He's the only possible culprit, but again, he seems harmless (when I'm watching him). I've wanted a Flagfish for some time as the Otos weren't touching some of the algae and Flagfish have a reputation for eating algae that no one else likes. If you think he's the culprit, will he settle down and change his fin-nipping ways (would a female companion help) or should I return him to the shop. I've only had him in the tank for 5 days and he does live-up to his reputation as an algae eater... he's quite a cute little guy. Thank you and regards, Michelle <Aha, the plot thinnens. My guess is the Flagfish is to blame. They have been reported to be fin-nippers. Not consistently, but frequently enough that I'd be cautious about keeping them in a community tank. They are, as you say, lovely fish and excellent algae eaters (they enjoy hair algae in particular). Now, there are two ways to approach this. One is to remove him and see if things settle down. The other is to build up a fair size group of them, so they concentrate on one another rather than the other fish. This is the way it works with tiger barbs -- more tiger barbs you keep, the less nippy them become. A tough choice. The problem with nippiness in fish is it isn't always consistent. I keep pufferfish in a community tank, and although they did nip the Corydoras, once I removed the Corydoras, they've been good as gold. Some species of fish maybe attract the attention of nippers. Corydoras seem to be real targets because they are slow and blunder into territories. They also seem to very stupid, and don't learn to avoid threats. In the meantime you do need to treat the fish with damaged fins before infection sets it. Cheers, Neale>

Re: possible fin-nipper? -- 06/29/07 > Hello Neale, Just wanted to say thank you. I know they're not the brightest, but Corys are such cute little guys, mine "groom" each other. I fear I'll be overstocked if I add too many more Flagfish. I'll watch for another week & see how it goes. The good news is the damaged tissue is growing back: I've been treating with Maracyn II and Melafix. So all is better for now. Thank you again. Michelle <Cool. Sometimes fin-nipping stops when the fish settle in. Perhaps the new fish are just hungry or annoyed? So if the other fish are healing up nicely then perhaps they've learned to avoid the nipper. Keep an eye on things though. I agree, Corydoras are the best! Make sure you have a go at breeding them -- baby Corydoras are cute beyond words. Cheers, Neale.>

Coralline algae growth/20 Gal pupfish tank:    2/16/07 In my pupfish tank there is red coralline algae starting to grow and spread all over the artificial corals I have in there.  Since they are artificial, over time will this be a problem?   <Nope> Thank you so much for your advice/comments. Regards,   Debra P. <Thank you for sharing. BobF>

Pupfish With Goiter?   1/11/07 Hi Crew, <Debra> I have a 20 gallon long saltwater tank housing pupfish, what I believe to be Cyprinodon variegatus.   <Mmm: http://fishbase.org/Summary/speciesSummary.php?ID=3181&genusname=Cyprinodon&speciesname=variegatus+variegatus> I acquired them when my brother had to move and said he had some "saltwater fish" that he was going to flush (yes down the toilet)  if he couldn't find someone to take them. <Poor practice, attitude>   I later learned he was offered the 55 gallon tank for free and these fish came with it.  I had an empty 20 gallon tank which I planned to set up for saltwater so I agreed (sight unseen) to take them (visions of the typical saltwater fish you see at the LFS danced through my head as I headed to his house to collect them.) <Some surprise now!>   It took me over two weeks to ID them on the internet.  The conditions the fish were kept were to say the least very poor.   The only maintenance he said he performed in the 4 months of having the fish was water top offs (tapwater treated with dechlorinator) and the lights were only occasionally turned on.  The gravel was filthy, the water reeked of tobacco smoke so I opted to start anew and unfortunately put the fish through a cycle.  The LFS (I no longer use) after selling me all the equipment they thought I needed, told me to "...do nothing..." and "...I might lose more than half the fish." <I do hope they fold... soon> About halfway through I learned about fishless cycling and products like BioSpira, Stability and Right Now! which I utilized all at some point to bring the tank under control. I did lose a few fish but they were fish in very poor condition when I acquired them.  I later learned more about live rock and started adding that to the tank as well (from new LFS).  I have a total of 15 pupfish of which four are new babies. well not babies now, only one has not reached maturity yet.   He/she is about 2 months.   The salinity is kept at 1.021 to 1.022 <I would keep this egg-laying toothed carps somewhere more "middling" in spg... 1.010 myself> set up with live sand and live rock.  It has a clean up crew of blue legged & red legged hermit crabs and snails consisting of Cerith, Nerite, one Margarita and one hitchhiking bumble bee snail; some bristleworms and I've seen a couple Brittlestars. <Cancel the above... need to keep the spg near where you have it for this other life>   I utilize a Prizm skimmer which I eventually plan to replace (now that I have a Tunze DOC Nano in my 10 gallon and can see a big difference in how skimmers should work) <Oh yes> and a Bio-wheel 150 filter with two filter pads.   Ammonia, nitrite & nitrate are 0.  About 8 cup water change daily.  After researching the site I think one of my pupfish may have a goiter.  Attached is a picture for your comment.  She is in the center of the picture and you can see the lump just under her right eye. <Mmm... rather than a goiter, I suspect this is evidence of some sort of tumorous growth... or parasitic mass... not endocrinologically linked... Only able to discern through necropsy, microscopic examination> Tonight I'm noticing some redness on the lower part of the lump.  Although I had not been monitoring or adding iodine I started last night using Salifert's Natural Iodine.  I also use this in my 10 gallon tank. <Good>   The reason for using Salifert's Natural Iodine is when I added some Kent's iodine to the 10 gallon tank and then tested the water using a Salifert Iodine test kit I could not get a reading. <Yes... this is one of Kent's poorer products...>   After switching to Salifert's Natural Iodine I can get iodide readings but still cannot get a reading on the combined iodate/iodine test. <This is a transient valence state...> At this point I'm not sure if it's me or I'm not adding enough iodine supplement. <Best to test... not to over-dose> Throughout the site Lugol's seems to be the preferred iodine supplement. <Mmm... only due to its easy availability> Will the Salifert test kit easily read the Lugol's iodine levels in the water or is another test kit needed? <It will read sufficiently to give indication of presence of useful amounts of this element> Why is Lugol's preferred over other Iodine supplements?  If this is a goiter she has, how much iodine do you soak the food in? <Very little... Iodine/ate will/can be absorbed sufficiently through the water> Should I place their food in a teaspoon and just add a couple drops of iodine? <A drop will likely be more than enough... and much of any may make foods unpalatable> They are fed twice daily a variation of Formula One flakes or frozen Formula One, Spirulina, or rolled seaweed on a clip.  If adding iodine to the food, should I also continue to add iodine to the water and of course monitor it with testing? <Yes>   The current level for iodide is .03, but as stated earlier I can't seem to get an iodate reading. <Not to worry...> Will the addition of iodine to their food have any negative affects on the invertebrates or the smaller pupfish? <Overdose exposure could, yes> In other words, is there any chance of an overdose? <Yes, though small> On another note, from what I've read in the wild the typical lifespan for pupfish is approximately one year.  Do you have any knowledge of how long they may live in captivity? <Yes... a few years... as shown in the fishbase.org link above... maximum longevity is about 4.4 years in the wild>   In my research all I've found is "...can live longer in an aquarium setting." but nothing definitive.  They have wonderful, spunky, playful personalities... but I keep hoping for no more babies! Thank you so much,  Debra Piedra <Do post what you have in the way of young on the Internet, ask your local stores if they'd like to sell... Bob Fenner>

Ameca splendens "fainting" Hi Bob: Thank you for letting me put some of your articles on my web site Aquarticles, which has now been done. Now I have "discovered" you, I find I have a question!- I wrote a piece about the Butterfly Goodeid Ameca splendens, (Fish Breeding/Three Unusual Livebearers) in which I mention a curious habit they have, of "fainting" as soon as they are caught in a net - they lay on their side as if dead, but come to life again immediately upon release. This is not cause by stress or over-exertion, since it happens even if they are caught with the first dip of the net. It is particularly noticeable with younger fish. Has this reflex been written about anywhere? <Likely so... do know of this "reflex defensive mechanism" with "baby birds" like Chickens (Gallus)... thought to have "survival value" for the individuals/species in avoiding predation... Don't recall such being recorded about Goodeids... Would do a library/computer search on the species, behavior: http://www.wetwebmedia.com/litsrchart.htm> Does it have a name? <Probably... but I don't know it, yet> Do any other species do this? <Assuredly yes... many species young that have slow neural development... neoteny... "faint" with certain types of stimulation...> What could be its advantage in nature? <Imagine being a snake, coming up on a palatable meal/organism, having it, instead of "running away", faint on the spot... you might well "leave it alone", continue in search of other prey... Or, imagine circumstances that might "scare to death" an individual Ameca splendens or likely cause its demise from struggling (like scraping its skin in a net...). The individuals, species that "pass out" might be more likely to survive, pass on their genes, including the disposition to hard wire behavior stated... than ones without> I would like to add more info. to my article. I posed the question in the newsgroup alt.aquaria but got no satisfactory answers. Sincerely, Howard Norfolk, Aquarticles.com <Be chatting. Bob Fenner> 

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