Threatened fishes of the world: Girardinichthys viviparus (Bustamante 1837) (Cyprinodontiformes: Goodeidae)

Abstract

Common name: Mexclapique (Bustamante 1837) or Chapultepec splitfin. Conservation status: Endangered, NOM-059-ECOL-2001 (Diario Oficial 2002); and critically endangered (CRA1ce+2ce+2abc), IUCN (ContrerasBalderas and Almada-Villela 1996). Identification: Maximum SL 65 mm; at present, males reach only 27 mm and females 39 mm. Dorsal fin, 18–26 rays; anal fin, 20–27 rays. Teeth conical. Scales in lateral series, 40–43. Usually 15–18 gill rakers. Trophotaeniae: two long anterior processes and two shorter posterior processes. Dorsal, anal and caudal fins show a black band terminally in adult males.Distribution: Endemic to Basin of Mexico: Lakes Xochimilco, Zumpango, Texcoco and Chapultepec (Alvarez del Villar and Navarro 1957). Abundance: Abundant in artificial pools in Lake Texcoco, scarce in Lakes Xochimilco and Chapultepec, and absent in Lake Zumpango.Habitat and ecology: In Lake Texcoco, it inhabits highly productive saline pools; water hardness (1,549 mg/l), alkalinity (412± 70.21mg/l), conductivity 10,254±444mS/cm, pH7.82± 0.17, well oxygenated and turbid water, water temperature 13–21°C. Reproduction: March to October, viviparous with multiple reproductive cycles, with occasional superfetation. Females reach sexual maturity at 1 year. Fecundity, 15–47 embryos (Diaz-Pardo and Ortiz-Jimenez 1986). Threats: Habitat loss due to urban and industrial development and water extraction (Contreras-Balderas 2005). Wastewater inputs in Xochimilco (including heavy metal and pesticides) elicited early warning biomarkers damage in G. viviparous (Lopez-Lopez et al. 2006). Conservation action: The National Water Commission maintains the species in artificial pools in Texcoco. Xochimilco has been included in the RAMSAR wetlands since 2004 and was Environ Biol Fish (2009) 84:11–12 DOI 10.1007/s10641-008-9380-4