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This is just a basic report which may tempt you to have a go with an attractive Livebearer which is easy to keep. I'd had a bit of a break from Livebearers so when I saw these in "Aqualife", my local aquatic centre, I decided to buy two pairs. This is a S. American species popularly called the "Dusky Millions Fish" or "Speckled Mosquito Fish" They were ideal for a smaller planted tank, they were a lively fish and added a dash of colour with their movement around the tank.  They are only around 2 cms in size, although the females being plumper seem to be slightly larger. One of the females was really attractively marked and could certainly match the male for subtle body colours and markings.  Fry Just one week later I spotted 3 fry moving about near the surface using the cover of some Nitella and Amazon Frogbit. They were around 4 mms in size and quite an elongated, plain, slim fish. I say "plain" fish but most of the fry had just one blotch around the middle of their body. The following morning, there were still only 3 fry which seemed very unsatisfactory and nowhere near the numbers stated in Baensch (10-40 fry) and John Dawes' book "Livebearing Fishes" (15-80 fry).  Unusual birth sequence.. Also, despite careful observation I had seen no sign of the reported unusual birth sequence;- according to Baensch Vol.1;- "In most cases the fry leave the mother's body "rolled together" and sink to the bottom where they remain for an hour before becoming untangled and freeswimming". Had something gone amiss with this "delayed" free swimming phase and reduced the numbers? I watched for a while and although the fry caught the eye of the adults and they did move towards them, they didn't pursue them with any real intent.Therefore I'm pleased to report that it's safe to leave the fry with the adults. At 6 weeks old they were a little under 1 cm in size but some young females were still lacking the black speckles. Certainly nothing like the many bold blotches on, what I considered to be, very striking parents.  During the next few weeks growth was quite slow, but at last the juveniles' blotches gradually increased. They now had the appearance of the two youngsters below which had reached around 1 cm in size.  It seemed to be the males who were in fact developing the blotches first . This juvenile male below is now over 1cm in size and pleasingly has the markings of the adult male.  Another small drop.... When the third drop arrived, it was quite difficult to do an accurate count, but I could see possibly 6 new smaller fry. So I was still getting far fewer than the reported numbers quoted in the books. These new youngsters were quite easy to spot near the surface plants, where they were feeding well on crumbled Spirulina flake. By now, with females from the first drop having their young, numbers were building up nicely even with single figure drops. This was now a busy aquarium with a lot of activity, with young of various sizes moving in and out of the dense Nitella plant. Summary As I stated previously, a very uncomplicated species to keep but with the attraction of very variable markings. This in turn adds a surprise element to the colour and amount of speckles of the offspring. Therefore it's all positives;- a peaceful species, can be kept in a small tank and left to their own devices, will thrive in a colony situation. A further bonus being that there isn't a skewed sex ratio with the fry (unlike my Phallichthys fairweatheri!);- a very easy to cope with, almost perfect 50% ratio. As a result I was able to trade in a good many pairs in one batch at "Aqualife" where they were soon moved on. Copyright Text and photos; Ivor Hilton. |