(Article initially written for the Silicon Valley Aquarium Society newsletter, as a "species journal" article.)
While doing some research while seriously getting back into fish
keeping for the first time in some years, I realized I kept coming across one
totally new fish again and again—the Endler’s Livebearer. Most of the information I stumbled across was
on the “Are they a guppy or are they not?” debate. (This was before the
Endler’s was officially classified as Poecilia wingii in spring of 2006). This aroused my curiosity, so of course I HAD
to have some.
I found male “Endler’s” at a couple local fish stores, but
ran into two problems—first, a complete absence of female Endler’s, and second,
the fact that the available “Endler’s” really looked like Endler x guppy
hybrids, with lyre tails, extended swords, and snakeskin patterning I was sure
I’d never seen in any quality information page on the fish. (I later learned
this was an issue with the suppliers, not the stores themselves.) So eventually I turned to EBay and Aquabid,
and won an auction on a pure breeding pair with 4 unsexed, but mostly grown,
fry of theirs.
My first sign that these fish were not guppies was when they
arrived in the mail, well packed in a big Kordon breather bag, and I realized that
not only were there 6 near-adult fish, there were ten newborn fry in the bag, alive
and healthy. Cannibalism was one of the
factors that most turned me off to “traditional” livebearers in general and
guppies in particular, so I was shocked and thrilled to find the little ones
unharmed.
The whole lot went into a Marineland Eclipse 12 gallon that had been
set up as a species tank for them, and they settled in happily and
quickly. The mature female did not drop fry the next
month, which I’m attributing to stress, but in the meantime the juveniles quickly,
grew and differentiated into young adults. They turned out to be 2 males and 2 females, and the next month all 3
females dropped fry—the large original had over a dozen, the younger two
dropped 2 and 3 respectively. They’ve
been breeding reliably since then, and the “special delivery” fry became
sexable as well at between 2 and 3 months, although they have not yet started
to breed.
Endlers are very easy keepers. Really, just keep them wet. They'll
take any sort of food, including flakes. They are not at all fussy
about their pH, and can tolerate a range from 6.0-8.0, although there
is no reason to not just keep them near neutral. Water temperature
is equally forgiving. Their ideal range is the normal tropical
aquarium range, 74 to 78 F, but can tolerate water into the high 60's to the high 80's.
They are extremely hardy little fish. I’ve had a fry loss
here and there, but have not had a single Endler’s die after a week of age, and
I’ve had the colony for nearly 6 months. They were the only species in my fish
room to survive a 2-week long heat wave (in the 100’s, without AC) with no
losses. Extreme sensitivity to water
fluctuations and high loss rates caused great frustration with fancy guppies,
and are major reasons why I have not kept them for many years.
The basic color pattern for a male Endler’s starts with a
big black “comma” running from his dorsal fin to his gills. (The comma is the
first marking to appear, and the first sexual distinction—it shows even before
the gonopodium is visible). The tail is mostly clear, with a bright metallic
orange streak on each edge. Typically,
the bottom streak runs the full length of the tail while the upper streak is
roughly half that long. The body then has mottled patches of the same metallic
orange and an equally metallic lime green. A metallic baby blue occasionally shows up, sometimes on the body, often
on the dorsal fin. The females, when
young, resemble female wild guppies, but become a bit more distinct as they
age. Once they reach about one and a
half times the size of the male, their plain silver/gray color begins to take
on a very pretty bronze or gold hue. Their scales pick up more pigment on the
edges, giving them a clear “fishnet” or pineapple pattern as the body color
deepens. Occasionally, the females will
pick up a nearly transparent blue shimmer on the dorsal or anal fins. Although
the females are plain by many people’s standards, and somewhat of late bloomers,
to me they are very simple but quite elegant fish when they mature.
Endler behavior patterns are distinct from the guppy, as
well, particularly regarding their courtship. Male guppies are notorious for attempting to sneak up on and mate with
anything that moves, and some things that don’t, and have been known to gang up
on and harry females to exhaustion and death. Endler’s don’t partake of this
same behavior. They’re not “sneaky”
about trying to get a poke in anywhere they can—they actually court their
females and almost remind me of little bettas. They hover in front of the
female they’re trying to impress, flutter their fins, show off their colors,
and display like tiny swimming peacocks. If the female seems uninterested, they may try to step up the show, but
if she swims off, they’re not prone to sneaking up behind her and trying to
mate anyway.
Endler’s are a fantastic little livebearer for someone
looking for something a bit different, and in fact rekindled my interest in livebearers for the
first time in a decade, and led me to recently begin working with Heterandria formosa (“least killifish”),
halfbeaks, and goodeids as well. They
make a wonderful, colorful display for a small tank and I feel they deserve a
place equally in a small casual office desk tank or in the breeding rooms of a
dedicated hobbyist.