Puntius everetti, A.H. Everett's Clown Barb

Puntius (lateristriga x) everetti (Clown Barb).  Puntius lateristriga was described in 1842 by the pioneer ichthyologist Achille Valenciennes. The British herpetologist George Albert Boulenger named P. everetti in 1894 to honor its discoverer, Alfred Hart Everett, a dedicated amateur who sold  to the British Museum two collections of fishes and herps made in Sarawak, on the northwest coast of Borneo.
 
 
Have these two similar species within the B. pentazona group, according to Yasuhiko et al. 1977,  been carelessly hybridized in captivity? The "Clown Barb," Puntius everetti, has caused confusion since it was first imported, initially to Hamburg on the eve of World War I, then to New York, where it was miscalled "Barbus lateristriga" until the "real" B. lateristriga turned up in 1932.
 
 
The English call this the "Spanner Barb." The confusion is excusable, for both these barbs have crisp silver and black juvenile patterns but develop more blurred and colorful mature patterning. Even the ichthyologists have been misled: in 1957 W. Klausewitz declared that a "Barbus zelleri" that had been described by Ernst Ahl was identical with a juvenile P. lateristriga. But I think that captive-bred populations of the Clown Barb, the "Puntius everetti of aquariums" have also been carelessly hybridized to some extent with Puntius lateristriga. And then there's just the possibility that these two similar barbs, with overlapping natural distributions and interchangeable fin and scale counts, were never genuine separate species in the first place. Gunther Sterba 1967 gave completely overlapping fin formulas for P. everetti and P. lateristriga, two barbs that occur widely in overlapping populations on the Malay Peninsula, on Sumatra, Java, and Borneo, and the table in Yasuhiko et al. "Comparative morphology and interspecific relationships of the cyprinid genus Puntius" (1977) makes no morphological distinctions between the two, which Yasuhiko suggested were in the process of speciating from a common ancestor. Both species also occur naturally  on some smaller islands that remain in the now-drowned watershed of the vast Ice Age river paleogeographers call the Sunda River, which joined all these areas into a single freshwater drainage basin until  as recently as 8000 years ago.
  
V.P. Vasiliev wrote an article, "Chromosome numbers in fish-like vertebrates and fish" in the Journal of Ichthyology, 1980, v. 20(3), pp 1-38, mentioning these two species. But Maurice Kottelat, A.J. Whitten, S.N. Kartikasari and S. Wirjoatmodjo, in Freshwater Fishes of Western Indonesia and Sulawesi, 1993, reckoned them separate genuine species in the wild.
 
P. lateristriga is naturally found from Thailand and the islands of Sumatra and Java to the western drainages of Borneo, in clear mountain streams strewn with rocks and boulders, often below waterfalls. That habitat description should suggest that the advice you generally hear, which is to keep these fishes slightly on the warm side, 76-84º, might be keeping these fishes a little too warm. They'd appreciate some extra current and plenty of surface oxygen exchange. And though they'll school loosely as youngsters, as they mature they turn into solitary hiders. In their natural habitat they can get to 18cm. (Puntius everetti remains a smaller fish, to 10cm.) Females will fill with eggs after a year, but males take about 18 months to reach sexual maturity. I inherited a mature male about 10 cm. total length. His scaleless head, with two pairs of barbels, is a dusty purple-brown; his back shades to olive, each scale with a mushroom-colored edging. His flanks are overcast with an iridescent yellow, lightly peppered with golden guanin dusting, that shades to a silvery belly. He has four blue-black vertical markings of blotchy bars on his flanks and a distinctly different horizontal scheme, a warm ink-black horizontal streak down the flanks and blotch on the caudal peduncle. His fins have rosy-brick rays fading out distally and milk-white edges to his dorsal and tail fins; the first ray of the dorsal dorsal fin is mushroom purple-brown. In Baensch 1, p.387, the illustration of P. everetti shows the same four vertical blotches that my fish has, even to the ink-black informal ocellus that overlies the vertical band on the caudal peduncle.
 
A secret to the confusing variability of P. lateristriga lies in the two different black patternings that are superimposed on each individual fish. It certainly looks as though two different genetic pathways, each coding for a black patterning, were concerned. One sequence appears to code for the iridocytes that form the blue-black splotchy vertical bars. The other sequence independently would be coding for the melanin-produced interrupted horizontal streaking. The two kinds of black are quite distinct when you look at the fish. My hunch is that when a closer look is taken, using DNA sequencing, any attempt at a consistent genetic distinction of captive breeding populations of these two species will evaporate.
 
What's important to remember is that this little black and silver barb is a late-bloomer that might take 18 months to show the colors of sexual maturity. Almost all the images in the Web show immature specimens. It will need a 36-inch tank when it reaches maturity, and it responds to regular water changes with improved colors.
 
Puntius everetti at FishBase. Puntius everetti at Wikipedia.