Threatened fishes of the world: Pangasius sanitwongsei Smith 1931 (Siluriformes: Pangasiidae)

Abstract

Common name: Chao Phraya giant catfish (E), giant pangasius (E), pla thepa (Thai), pa leum (Lao), trey po pruy (Khmer). Conservation status: Endangered in Thailand (Humphrey and Bain 1990). Identification: Maximum size 300 cm TL, 300 kg. Long, dark filaments on anterior dorsal, pectoral, and pelvic rays (Rainboth 1996). Mouth width more than 17% SL (Roberts and Vidthayanon 1991). Distribution: Chao Phraya and Mekong River Basins in Southeast Asia. Abundance: The size and abundance of P. sanitwongsei has declined steadily over the past several decades. Smith (1945) reported fish up to 3 m from the Chao Phraya prior to 1920. By 1945, fish over 2 m were rare. By 1967, IUCN estimated fewer than 2,000 fish in the Chao Phraya (Humphrey and Bain 1990). P. sanitwongsei no longer occurs in the Chao Phraya River (Na-Nakorn et al. 2006). Along the Thai Mekong, fishermen report adult P. sanitwongsei disappeared around 1995. In Cambodia, fishers report a 60% decline since 1980 (Hogan et al. unpublished data). Habitat and ecology: Adults occur in deep pools areas. P. sanitwongsei is carnivorous, feeding on fish, shrimp, and crabs. Reproduction: Spawning occurs in April and May. Eggs adhesive, diameter of 2–2.5 mm, fecundity 433 600 eggs (41 kg female) and 876 800 (110 kg female). Broodstock show low genetic variation (NaNakorn et al. unpublished data). Threats: Overharvest, pollution, habitat fragmentation, and possible loss of forage base (Hogan et al. 2004). Lack of Environ Biol Fish (2009) 84:305–306 DOI 10.1007/s10641-008-9419-6