It is very difficult (if not impossible) to determine the sex of baby fish, for they have not yet developed distinguishing male/female characteristics. When your fish get older, you should be able to see the difference – I’m referring to both the gonopodium and the distinctive sword tail of the males.

In other words, all your swordtail fry (i.e. baby fish) will lack a sword and will have fan-shaped anal fins. Also, male swordtails are known to sometimes be late bloomers. In extreme cases, it may take up to a year for the distinctive male features to develop!

Hope this info helps, Ruth. And congratulations on your new batch of swordtail fry.

Best,
Luke

I bought 1 male and 2 female orange swordtails. The male had a sword, the females did not. After quarantine, I put them in a big 49 gallon bowfront tank and they had about 15 orange offspring, the oldest being 8 months. The mystery is all the offspring seem to be female (no swords), which doesn’t seem very likely. Any ideas what might be going on? Do the baby males remain latent as long as there is an alpha in the tank? Just curious…

Thanks in advance, Ruth

Thank you for your wonderful comment. It’s nice to hear that my efforts are appreciated

Regarding your question, a mated pair of discus will do great in a 96 gallon aquarium!

Of course, when keeping discus fish in pairs, it’s best to get a male and a female (as opposed to two fish of the same sex) so as to promote harmony. In other words, a male and female will get along splendidly, while two male discus fish may quarrel (with the dominant male imposing far too much authority on the submissive male for the submissive male to bear).

If you have hard water, buy a Reverse Osmosis machine (read about RO water in this Aquarium Care Article), which will allow you to produce prefect water for discus. Yes, an RO machine is a bit of an investment, but it more than pays for itself! I highly, highly recommend using RO water in any aquarium.

Other than these two bits of advice, it sounds like you have a fantastic setup in mind, Tommy.

Wishing you success and a beautiful aquarium,
Luke

Thanks for taking an interest. I am in the process of building TheSmileyFish Members Area. It’s a whole lot of work, but when done, it will include, among other helpful tools, video lessons and hands on video demonstrations. I am currently working with a videographer and editor to put it all together.

When completed, people who purchase my aquarium book will get a free two week trial (a free test run of the members area), after which time, they will have the option to continue subscription.

Both the aquarium book and the members area are coming together wonderfully! I’ve been working on getting everything together for over a year now. It’s a lot of work, but making this complete aquarium guide, a truly comprehensive resource like no other, is well worth the effort

Thanks in advance for the patience. I’ll post an article about the book and members area when all is ready.

Take Care Ivan.

Regarding your male (or female) platy: The sure-fire way to determine the sex of your platy is to look at the anal fin (see article above). If your platy has a gonopodium, then it’s a male (100%), and the spot is perhaps just an example of coincidental coloration.

Also, most pregnant guppies will display the dark spot (called a “gravid spot”) towards the back of the stomach, right in front of the anal fin.

Keep in mind however, that the gravid spot will get darker over the course of pregnancy (it does not appear right at the moment of fertilization). Also, her stomach will noticeably enlarge. If her stomach is still small, chances are that the gravid spot is hardly as noticeable as it will be, say, one week from now.

On the other hand, if the female guppy does not get bigger and doesn’t develop a clearly visible gravid spot, then she is not pregnant.

But, if you’re looking forward to raising guppy fry, don’t worry. As long as a male is present in your aquarium, the female guppy will be pregnant in no time.

Hope this info helps.

Thanks for posting and take care

I successfuly looked after a nice slightly planted community tank for my first go at fish keeping,, until when on holiday my friend managed to kill everything!!!! and then lost the will to do it all again. But now ive decided to get back into it and want a planted aquarium with a pair of discus, not sure on the other fish yet.

I was wondering whether my jewel 96 would be large enough to support this setup? I also live in an area with hard water.

Many thanks

Sounds like you’re planning a nice setup. Your choice of equipment is good (the canister filter you’ll especially appreciate).

There are a few things to consider regarding fish choice: temperature and pH (and, related to pH, water hardness/softness). I’ll cover some basic info first so that when I address your question specifically, it’ll make more sense

pH:

Let’s stat with pH (very briefly). pH is measured on a scale of 1 to 14. A reading of 1 to 6.9 indicates “Acidic” water; a reading of 7, “Neutral” water; and a reading of 7.1 to 14 “Basic” water.

pH, in turn, is largely affected by water hardness: the measure of dissolved minerals in the water. In freshwater aquariums, the harder the water is (i.e. the more dissolved minerals it contains), the higher the pH tends to be. That’s because “Hard” water is more likely to maintain (or support) a higher pH, while “Soft water (i.e. water with little dissolved minerals in it) is unable to keep the pH high, and gives in to the forces of Acidity, so to speak.

This relationship between water hardness and pH I describe above is termed “buffering capacity”. In other words, buffering capacity is the aquarium water’s ability to maintain a high pH. Here’s a hypothetical example/rational: hard water has many dissolved minerals in it, it therefore has a high buffering capacity, and therefore is able to maintain higher pH readings.

Okay, okay… so this is roughly how water hardness and pH work in freshwater aquariums. The important things to keep in mind are that 1) water with lots of dissolved minerals in it tends to have a high pH, and 2) some fish do best in water of a higher pH, while others prefer water of a lower pH.

The platies prefer water that is of a higher pH (in the 7.0 to 8.2 pH range). The guppies can live in water of a wide pH range (about 5.5 to 8.0), but, in my experience, they do best in water that is pH 7.0 or higher. The Otocinclus Catfish (cute little algae munchers, by the way) does best at a pH around the Neutral range. The other fish in your list will do well in water that has a pH of about 6.0 to 7.0.

Temperature:

Zebra danios like cooler water in the range of 65 to 75 degrees Fahrenheit. The other fish will do well in water of about 78 degrees Fahrenheit.

Also, keep in mind that Cardinal Tetras react poorly to cool water (and to rapid fluctuations in temperature, in general) and are not good candidates for shipping during winter.

Conclusions:

If you’d like to go with the lower to neutral pH, warmer water fish, I’d get the platies, guppies, and danios off the list.

Instead, perhaps a nice school of Harlequin Rasboras (nice looking, easy to care for fish) will make for a nice substitute. Rasboras are hardy and will make for a great first addition to your aquarium.

Also, if you can, try to obtain your fish from a Live Fish Store (LFS) near you, as opposed to getting them shipped to you. After all, when you buy the fish from a local source, you have the great advantage of being able to see if the individual specimens are healthy. Also, you avoid the risks of shipment. Of course, I understand that getting your fish locally may not be an option.

Also, if you’re new to the hobby, you may benefit from taking a look through my Aquarium Care series of articles on this site.

Finally, some of the concepts I cover at the beginning of this comment are complicated, so do let me know if I need to re-articulate something to make it more clear. Let me know if you need any further explanation or if you have any more questions TJ. As always, I’m ahppy to help.

Wishing you success with your new fish tank!