Wednesday, July 20, 2011

[Ichthyology • 2008] Oryzias bonneorum • A phylogenetic analysis and taxonomic revision of Oryzias and relatives (Adrianichthyidae)

Figure 38. Oryzias bonneorum sp. nov., holotype, Lake Lindu, Sulawesi Tengah, Indonesia, male, MZB 15499, male, 52 mm SL.

Ricefishes, known best by the model organism, the medaka, Oryzias latipes Temminck & Schlegel, 1846, comprise the family Adrianichthyidae, which ranges broadly throughout fresh and brackish waters of Central, South and Southeast Asia and the Indo-Malay-Philippines Archipelago as far east as Timor. Twenty-eight Recent species are recognized here in two monophyletic genera, Adrianichthys and Oryzias. Xenopoecilus and Horaichthys are placed in synonymy of Oryzias for the first time. Adrianichthys comprises four species from Lake Poso, Sulawesi, Indonesia. Oryzias comprises 24 species that live throughout the range of the family. A fossil genus and species, †Lithopoecilus brouweri from the Miocene of central Sulawesi, is included tentatively in the Adrianichthyidae. Evidence for the sister group relationship of adrianichthyids and exocoetoids is reviewed briefly and that relationship corroborated. Monophyly of adrianichthyids is likewise strongly supported here. Species groups within Oryzias are diagnosed as monophyletic largely based on osteology, colour pattern and meristic variation. They correspond only in part to species groups previously recognized based on chromosome constitution. Miniature species do not comprise a monophyletic group; disjunct absolute size in close relatives has evolved repeatedly. Oryzias latipes is a member of a species complex that includes O. luzonensis, O. curvinotus and the miniatures O. sinensis and O. mekongensis. A new species, Oryzias bonneorum sp. nov., is described from Lake Lindu, Sulawesi, Indonesia. Lectotypes are designated for Haplochilus celebensis Weber, 1894 and Haplochilus timorensis Weber & de Beaufort, 1922.

ADDITIONAL KEYWORDS: comparative morphology – homology – medaka – model organisms – miniaturization – phylogeny.

This study 'nov.':
Family Adrianichthyidae Weber, 1913
Genus Adrianichthys Weber, 1913
• A. oophorus (Kottelat, 1990a) comb. nov.
• A. poptae (Weber & de Beaufort, 1922) comb. nov.
Genus Oryzias Jordan & Snyder, 1906
• O. bonneorum sp. nov.
• O. sarasinorum (Popta, 1905) comb. nov.
• O. setnai (Kulkarni, 1940) comb. nov.

Figure 1. Oryzias dancena (Hamilton, 1822), the first described ricefish species, USNM 313908, adult female, 23.8 mm SL, above; adult male, 25.0 mm SL, below. Sri Lanka. Female is carrying a cluster of embryos.

Table 1. Classification of ricefishes, family Adrianichthyidae, as recognized in the present study

Figure 2. Approximate distributional limits of ricefishes, the family Adrianichthyidae, outlined and shaded. In the Philippines ricefishes are native only to the island of Luzon. Distribution throughout mainland China is estimated.

Parenti, L.R. 2008: A phylogenetic analysis and taxonomic revision of ricefishes, Oryzias and relatives (Beloniformes, Adrianichthyidae). Zoological journal of the Linnean Society, 154: 494–610. doi: 10.1111/j.1096-3642.2008.00417.x