Changes in the distribution of goodeids (Osteichthyes: Cyprinodontiformes: Goodeidae) in river basins of Central Mexico

Abstract

THE MEXICAN CENTRAL PLATEAU HOSTS AROUND 100 NATIVE FRESHWATER FISH SPECIES, 70% OF WHICH ARE ENDEMIC TO THE REGION. FRESHWATER ECOSYSTEMS IN THIS AREA ARE HIGHLY IMPACTED BY ANTHROPOGENIC ACTIVITIES. GOODEIDS ARE THE MOST REPRESENTATIVE FISH IN LAKES AND RIVERS IN THE CENTRAL PLATEAU. IN RECENT DECADES, THESE FISHES HAVE SUFFERED FROM WATER QUALITY DEPLETION AND MODIFICATION OF HYDROLOGICAL REGIMES, LEADING TO REDUCTION OF THEIR ORIGINAL DISTRIBUTIONS. TO UNDERSTAND CHANGES IN THE DISTRIBUTION OF SPECIES OF THIS FAMILY, WE DOCUMENTED LOCAL EXTINCTIONS OF ITS SPECIES AND ITS RELATION WITH THEIR SENSITIVITY TO ENVIRONMENTAL CHANGES. PREVIOUS DISTRIBUTION RECORDS FOR EACH SPECIES WERE OBTAINED FROM BIBLIOGRAPHICAL SOURCES AND MUSEUM COLLECTION DATA. WE COMPARED PREVIOUS DISTRIBUTION WITH MORE RECENT FIELDWORK DATA, WHICH WAS CONDUCTED BETWEEN 1999 AND 2004, IN 287 LOCALITIES IN 15 STATES OF THE COUNTRY. FIELDWORK COVERED 95% OF THE LOCALITIES SAMPLED IN PREVIOUS RECORDS. WE FOUND LOCAL EXTINCTION IN 68% OF THE LOCALITIES SURVEYED. IN 9 OF THE 18 REGIONS, SPECIES DISTRIBUTION WAS REDUCED TO HALF OF THEIR REPORTED AREAS. FIVE SPECIES HAVE DISAPPEARED IN 50% OF THEIR ORIGINAL DISTRIBUTIONAL RANGE, AND AT LEAST 2 SPECIES ARE ALREADY EXTINCT. WE CLASSIFIED GOODEID SPECIES ACCORDING TO THEIR VULNERABILITY AND LOCALITIES WERE CATEGORIZED BY THE QUANTITY OF LOCAL EXTINCTIONS. LOCAL EXTINCTIONS MAY AFFECT SPECIES VIABILITY, AND IT IS THEREFORE URGENT TO GENERATE AREAS OF CONSERVATION FOR GOODEIDS.