| Author’s
note: I happened to find myself with a surplus of the three species described
below, so before taking them to a meeting to be auctioned (our club has a "mini
auction" at the end of each meeting)), I wrote the following notes about them for the
newsletter I edited. The next month I asked one of our keen plant-keeping members to bring along three plant species and to write about them beforehand, which he did. May I suggest that you add interest and anticipation to your meetings by including newsletter articles about the fish your members breed and bring to meetings. THREE UNUSUAL LIVEBEARERS by Howard Norfolk First published in The Vancouver Aquatic Hobbyist Club newsletter Aquarticles 1) AMECA SPLENDENS: Butterfly Goodeid.
You have kept Poecilidae, but have you ever kept a Goodeid ? The three families of livebearing toothcarps all come from Central and South America: Poecilidae (guppies, mollies, platies and swordtails), Anablepidae, and Goodeidae. Ameca splendens is a Goodeid. Goodeids all come from Mexico, from a variety of niche habitats in the highland catchment area of the Rio Lema in Western Mexico, and Ameca splendens comes from the Rio Ameca basin (hence the name). Ameca splendens is endangered in the wild. They grow to be two or three inches long. The male is particularly attractive, with iridescent blue-green spotted flanks and a pale orange underside. His tail has a strong vertical black band and a bright yellow one. The female is more plain, but with her spotted silver body and squarish (rounded) tail reminds me of nothing less than a miniature big fat spring salmon! They will live in a wide range of water conditions and temperatures (13°C/55°F to 28°C/82°F) and are good community fish. They are very active and are voracious feeders, supposedly typically vegetarian, so I feed mine regular flakes and spirulina flakes, but find that they love frozen bloodworms or any other food for that matter. They will also eat filamentous green algae off plants and aquarium equipment. They are livebearers. Their young are few but are born large: up to ½" long (11cm.), fully developed and able to eat their adults' food right away. Gestation period is about sixty days, and in the womb the developing embryos have an umbilical cord (the trophotaniae) through which they obtain nutrients from the mother. During pregnancy the mother needs lots of food or she might abort. Fertilisation is required for each pregnancy (unlike Poecilidae). They breed readily when kept in a shoal, and once a few youngsters are present, the newcomers are left alone. The young like to hide near the surface amongst floating plants (in the wild they live amongst floating water hyacinths). The adults are fast, smart, and difficult to catch in a landscaped aquarium. But the young ones have a curious habit of “fainting” – floating on their side apparently dead - the instant they are caught in a net, or even chased by a net. They "come back to life" as soon as they are released. This is a defensive mechanism which makes them unattractive to predators that only eat "live" food. I wonder how many have been released for this reason when netted in the wild! I have them spread around various tanks now, but mostly in a 15 gallon species tank and in my indoor pond. (October 2002: Putting them in my indoor pond turned out to be a problem - they bred so successfully that they virtually took over the pond! I couldn't catch them, so I had to completely drain the pond and remove every single one). They reproduce readily in a flock setting without being given any special treatment. I find that I get far more females than males. P.S. July 2002: I have had a few enquiries about the availability of these fish, but do not have the inclination to package and ship them. To this end I have given a stock to my friend Jason Shaw, of Campbell River, British Columbia, Canada, who is selling them via his web site www.anythingfishy.ca 2) HETERANDRIA FORMOSA: Mosquito Fish, Dwarf Top-minnow, Dwarf Livebearer, Least Killifish, Lesser Killifish, Pygmy Livebearer.
Heterandria formosa is not a killifish as some of the common names suggest, but is in fact the smallest species of livebearer, and for that matter one of the smallest fish species in the World, and until recently was considered to be the smallest known vertebrate in the U.S.A. The males grow to 0.8", and the females 1.4". They are tiny North American fish, found in weedy, slow moving fresh and brackish waters from Florida to North Carolina, and were recently also discovered in Texas. They are not normally found in pet stores, since they are so small and not too showy, being olive green in colour with a dark brown line running down the side of their body. Don't say I told you because it says so in the books, but the males proudly sport very large gonopodiums! They accept all foods but should have some vegetable matter. I feed mine regular flakes and spirulina flakes, pinched to a small size. They are not greedy eaters and are rather lazy swimmers, and are best kept in a well planted small species tank at room temperature in hard, slightly alkaline water with some tannin. Both adults and young like to hide amongst plants. The young are produced continually on a "production line" system ("superfoetation") rather than in distinct broods, and it is said that adult females can produce one or two fully developed young almost every day of their adult lives. I acquired a young pair from our member Matt Hennig a few months ago, and now have well over a dozen. Despite being a North American fish, Matt's strain came from Germany. Having kept them before and liking them, Matt's father bought some in Germany and flew here with them in a bag in his shirt pocket, aerating the bag every now and then with a straw! 3) POECILIA sp. "ENDLERS" : Endler's Livebearer, Endler's Poecilia.
Endler's livebearers are small guppy-like fish. They were first collected in 1937, and then re-discovered in 1975 by Professor John Endler. He took the fish to The New York Aquarium, from where they were taken to Germany. German aquarists bred them, sometimes mixing them with guppies of various breeds, and in the 1980's they found their way back to America, and to Japan and elsewhere. Dr. Endler says that the "Endler's livebearer" is its own species, since although it will interbreed with the guppy (many livebearers will interbreed), it will only produce F1 hybrids. It should be kept apart from guppies unless hybrids are desired. "Endlers" were found in a small lake called Laguna de Patos, near Cumana, in the hot dry coastal desert area of north-eastern Venezuela, and were rumoured to be in another lake nearby. The Laguna is a warm (81°C) marsh, with hard brackish water, and is green with unicellular algae. It is only two miles from the city dump, and Dr. Endler speculated in 1995 that the fish may be extinct in the wild by now. I have also been told that a resort has recently been built in the area and that the lake has been filled in. The female is larger and looks like a female guppy, but the male is a very unusual looking little jewel of a fish, with iridescent metallic green, orange, gold and black blocks of colour, a white dorsal fin and a red forked tail. The markings are unusually laid out: if there is such a thing as an "Art-Deco" fish, this is it! The water in which they were found was so green with algae that it is supposed that the bright colouration evolved as the only way a female could see a prospective mate! As with many other fish, the most dominant males are the brightest coloured, which is believed due to hormones in alpha males. The intensity of the colour patches also varies according to the conditions this fish finds himself in, and what is more, even in the wild, there were further variations in colour between individuals (e.g. 10% of males had black pectoral fins). Endlers are active fish that swim at all levels and eat and breed readily, and should be happy wherever you might otherwise keep guppies. Author's
note: I added this to the end of the article in the club newsletter: |
