Bulletin of Fish Biology Volume 9 Nos. 1/2 15.12.2007 93-97 Short note/Kurze Mitteilung New colour genes in the guppy, Poecilia reticulata (Peters, 1859) Neue Farbgene beim Guppy, Poecilia reticulata (Peters, 1859) Michael Kempkes Am Mühlenberg 25, D-46419 Isselburg-Anholt, Germany, michael.kempkes@web.de Zusammenfassung: Reziproke Verpaarungen vier verschiedener spezifisch gefärbter domestizierter Guppy-Stämme (Caeruleus, Maculatus, Lutino, Metallicus/Pink) mit Stämmen bekannten Erbgangs (Pauper/ Grau, Maculatus/Grau, Albino, Gold) ergaben, dass diese Farben auf fünf Farbgenen beruhen, von denen drei autosomal-rezessiv vererbt (Lutino, Pink, Metallicus) und zwei (Moscow, Caeruleus) vom Y-Chromosom kodiert werden. The guppy, Poecilia reticulata, is the first fish species in which a colour gene (Maculatus) was discovered strictly linked to the Y-chromosome (SCHMIDT 1920, WINGE 1922a, b, 1927). In the first decades of the last century further phenotypes and colour genes have been described, also since the 1940’s some colour genes from domesticated strains have been described (for review see LINDHOLM & BREDEN 2002).The present note describes five new colour genes in four strains of guppies bred since many years in aquaria and named herein Caeruleus (latin = sky blue), Lutino (derived from luteus, latin = deep yellow), Metallicus (latin = metallic) and Pink/Moscow. Caeruleus-males have a light blue metallic colour extending from the head to the base of the caudal fin; in the middle of the body a black spot is present and the colour nearby is a little bit greenish. The unpaired fins are slightly white, light yellow with little black spots or transparent (fig. 1 a). Females are uncoloured. Lutinomales have a double sword; the body colour of both sexes is intensely yellow; eyes are darkred (fig. 1 b). Metallicus-males have a double sword and a body-wide blue-metallic colouring (fig. 1 c). Females are uncoloured. Pink/Moscow-males have a tail like wild guppies. The anterior part up to the middle of the body and the pectoral fins are dark blue. Intensity may slightly change. Body colour of both sexes is similar to the mutant Gold (GOODRICH et al. 1944), which, however, is more yellow in the latter and a dark border of scales is largely missing ventrally. Especially juveniles show a pink pectoral region (fig. 1 d). The known strains used for crosses were Pauper, in which males have a horizontal red spot at the caudal peduncle and a black spot just behind the red one. The body colour is grey (fig. 1 e). And Maculatus, in which males have a red spot in the middle of the body and a black spot at the dorsal fin; the body colour is grey (fig. 1 f). In both strains females are uncoloured and male colouration is determined by loci on the Y-chromosome (WINGE 1922b, 1927). To check more thoroughly the strains Lutino and Pink I used the strains Albino and Gold in some crosses. All strains were kept at 26-27 °C in 120 l tanks, which were planted with Cryptocoryne moehlmanni, Riccia sp. and Vesicularia dubyana. The guppies were fed with Artemia salina, Daphnia sp., crushed Spirulina and high quality flake food. For each cross two of three males and two of three females were mated and kept in 45 l tanks under similar conditions. The offspring of each breed was raised separately until colouring was fully developed. Tables 1-4 show the guppy strains, the number of crosses and guppy strains (abbreviated), the crosses (males first, females last) and data of the F1 generation. Abbreviations: Caeruleus (Ca), Lutino (Lu), Metallicus (Me), Pink/Moscow (Pi/Mo), Pauper (Pa), Maculatus (Ma), Albino (Al) Bull. Fish Biol. 9 (1/2) 93 a b c d e f g Data in table 2 indicate an autosomal-recessive inheritance for the ground colour Lutino. Autosomal-recessive characters in P. reticulata follow the Mendelian rules (K IRPICHNIKOW 1987), however, Lutinos did not reach the theoretical proportion, i.e. 1:4 (Lu 2) pairing with siblings) or 1:1 (Father/daughter pairing) 94 Figs. 1 a-g: Representatives of the guppy strains, in which the colour genes were detected (a-e) and the strains Pauper and Maculatus used for crosses (f-g). a Caeruleus; b Lutino; c Metallicus; d Pink; e Pink/ Moscow; f Pauper, g Maculatus. Abb. 1 a-g: Vertreter der Guppy-Stämme mit den neuen Farbgenen (a-e) und der für die Kreuzungen verwendeten Stämme Pauper und Maculatus (f-g); a Caeruleus; b Lutino; c Metallicus; d Pink; e Pink/ Moskau; f Pauper, g Metallicus. (Lu 3). Deviations may be attributed to the relative small number of offspring. In guppy populations with a mixed age distribution the yellow offspring was selectively feed by the adults. Also prenatal lethal factors cannot be excluded as discussed e.g. for albinotic guppies (HASKINS & HASKINS 1948; see also KIRPICHNIKOW 1987). Results listed in table 1 indicate that Caeruleus is y-linked. Table 3 shows that Metallicus appears to have an autosomal-recessive inheritance, although the theoretical proportions could not be obtained, e.g. 1:2.67 (Metallicus: Pauper) in Me 2 instead of 1:3, and 1: 2.71 (Metallicus: males with other colour patterns) instead of 1:3 in Me 5. Results in table 4 indicate that Moscow is ylinked, whereas the body colour Pink has an autosomal-recessive inheritance, which was questioned previously (e.g. LUCKMANN 1990, FOERSTER 1993). Acknowledgements Literature FOERSTER, W. 1992. Eine weitere Überraschung beim Pink-Guppy. DGLZ-Rundschau 15, 31-32. GOODRICH, H. B., N. D. JOSEPHSON, J. P. TRINKAUS , & J. M. SLATE ,1944. The cellular expression of two genes in Lebistes reticulatus. Genetics 29, 584-592. HASKINS, C. P. & E. F. HASKINS (1948). Albinism, a semi-lethal autosomal mutation in Lebistes reticulatus. Heredity 2, 251 – 267. KIRPICHNIKOW, V. S. (1987). Genetik der Fischzüchtung. VEB Deutscher Landwirtschaftsverlag, Berlin. LINDHOLM, A. K. & F. BREDEN (2002). Sex chromosomes and Sexual Selection in Poeciliid Fishes. The American Naturalist 160, 214-224. LUCKMANN, H. (1990). Die Grundfarbe des PinkGuppys. DGLZ-Rundschau 17, 4-8. SCHMIDT, J. (1920). Racial investigations. IV: The genetic behaviour of a secondary sexual character. Comptes Rendus des Travaux de Laboratoire Carlsberg 14(8), 1-12. WINGE, Ø. 1922a. A peculiar mode of inheritance and its cytological explanation. Journal of Genetics 12, 145-162. WINGE, Ø. 1922b. One sided masculine and sexlinked inheritance in Lebistes reticulatus. Journal of Genetics 13, 201-219. WINGE, Ø. 1927. The location of eighteen genes in Lebistes reticulatus. Journal of Genetics 18, 1-43. I thank the Japanese guppy breeder, who donated me the Caeruleus-strain during the world guppy show in Vienna in June 2000 and Harald AUER, Ömer GÜLMEZ, Kees DE JONG, Hans LUCKMANN, and Claus OSCHE, who gave me some individuals of the different strains. I also thank my friends Frank BUDESHEIM (Kerpen) and Fred N. POESER (University of Amsterdam) for several good discussions on guppy genetics. Many thanks to Hartmut GREVEN (University Düsseldorf) for his support. Special thanks go to Chris LUKHAUP, who took the photos. Received: 18.05.2007 Accepted: 10.11.2007 Bull. Fish Biol. 9 (1/2) 95 Tab. 1: Crosses with Caeruleus. Tab. 1: Kreuzungen mit dem Stamm Caeruleus. Tab. 2: Crosses with Lutino. Tab. 2: Kreuzungen mit dem Stamm Lutino. 96 Tab. 3: Crosses with Metallicus. Tab. 3: Kreuzungen mit dem Stamm Metallicus. Tab. 4: Crosses with Pink/Moscow. Tab. 4: Kreuzungen mit dem Stamm Pink/Moscow. Bull. Fish Biol. 9 (1/2) 97