Vertical Movements of a Mekong Giant Catfish (Pangasianodon gigas) in Mae Peum Reservoir, Northern Thailand, Monitored by a Multi-Sensor Micro Data Logger

Habitat use and movement of hatchery-reared F2 Mekong giant catfish in the Mae Peum reservoir, Thailand, studied by acoustic telemetry

“…However, in September, the possibility that the thermocline as well as hypoxic water limited the vertical movement of the fish cannot be discounted. This hypothesis is supported by a previous report that hypoxic water might limit the vertical movement of F1 giant catfish [18]. Similar movement patterns in relation to hypoxic water have also been observed in both marine and freshwater fishes [27][28][29], although fish sometimes dive down in hypoxic water; for example, the mudminnow occasionally dives below DO stratification to forage [28].…”

“…1). The data of vertical profiles of water temperature and DO, measured at 4-14 sites throughout the reservoir on 29 July, 17 December 2003, 2 August, 10 October, and 21 December 2004, were reused in order to help understand the environment in the reservoir [18,19].…”

“…Among this biological research, detailed understanding of habitat use and movement patterns with environmental fluctuation is prominently important for design of protected areas (residential and spawning areas) [11][12][13][14]. However, only a few studies have described the habitat, movement patterns, and migration of giant catfish [15][16][17][18][19] as well as other catfishes [20][21][22][23]. In the Mekong River, wild giant catfish may use deep holes as residential habitat and may also engage in long-distance spawning migration [4,24,25].…”

ENDOGENOUS CIRCANNUAL RHYTHMICITY IN BODY MASS, MOLT, AND PLUMAGE OF GREAT KNOTS (CALIDRIS TENUIROSTRIS)

“…To our knowledge, this is the first quantitative study of the periodic feeding rhythm associated with a long-term fasting in teleost fish, although numerous instances have been described in avian and mammalian species (Hissa, 1997;Piersma et al, 2008). According to previous studies, adult catfish use shallow waters as a feeding habitat (Mitamura et al, 2007) and are likely to feed mainly on filamentous attached macroalgae of the Cladophora spp. (Akagi et al, 1996).…”

“…The goal of our study is to understand the ecological features of the catfish. Although Mitamura and colleagues have extensively described the movement patterns of this fish by performing telemetry studies (e.g., Mitamura et al, 2007Mitamura et al, , 2008Mitamura et al, , 2009), other aspects of its ecology are less well understood (Hogan, 2004). Although many aspects of the ecology of P. gigas are known, we have hitherto focused on feeding ecology, because feeding ecology is one of the important information for fish culture management.…”