PREY FORAGING PATTERNS OF MARBLE GOBY (Oxyeleotris marmorata) FINGERLINGS TO DIFFERENT PREY TYPES
Abstract
A study was conducted in glass aquaria to observe foraging behaviors and patterns of marble goby (Oxyeleotris marmorata Bleeker 1852) fingerlings on different prey types and to investigate prey selectivity, prey capture successfulness and effects of starvation on foraging patterns at the University of Agriculture and Forestry, Vietnam. Marble goby fingerlings of 40.0mm in total length were deprived for 1, 2 and 4 days prior to observing their foraging patterns, predator-prey encounters and prey selectivity using two video cameras which were set up for recording the top and side views of predation processes. The results showed that the typical feeding behavior of marble goby fingerlings included three phases: aim, encounter and capture. After ingesting prey, they moved downward obliquely through the water column and continued their searching. They darted after prey unsuccessfully at the farther range of about 22 mm for silver carp (Hypophthalmichthys molitrix) and tilapia (Oreochromis sp.) fry and 10 mm for rice field prawns. Video recording revealed three patterns of marble goby foraging behaviors. Type A showed the sit-and-wait predatory behavior which occurred to marble goby subject to 1-day starvation. The common foraging pattern was type B - hover search, which included swimming, stationary for a little while then accelerating towards fish fry. When marble goby fingerlings were under deprived condition, the foraging pattern was multiple feeding (type C), for which marble goby fingerlings crept, swam and chased prey throughout water column, attacked all prey encountered during one feeding action. It took only 2 - 5 seconds to strike silver carp fry, but 2 - 10 seconds and 3 -20 seconds to capture tilapia fry and rice field prawns, respectively. The percentage capture success of marble goby fingerlings to silver carp fry was 98.06% compared to 68.35% for tilapia fry and 11.36% for rice field prawns. It was found that the deprivation caused significant response to prey ingestion.
Keywords: Marble goby (Oxyeleotris marmorata), Feeding behavior, Prey foraging
A study was conducted in glass aquaria to observe foraging behaviors and patterns of marble goby (Oxyeleotris marmorata Bleeker 1852) fingerlings on different prey types and to investigate prey selectivity, prey capture successfulness and effects of starvation on foraging patterns at the University of Agriculture and Forestry, Vietnam. Marble goby fingerlings of 40.0mm in total length were deprived for 1, 2 and 4 days prior to observing their foraging patterns, predator-prey encounters and prey selectivity using two video cameras which were set up for recording the top and side views of predation processes. The results showed that the typical feeding behavior of marble goby fingerlings included three phases: aim, encounter and capture. After ingesting prey, they moved downward obliquely through the water column and continued their searching. They darted after prey unsuccessfully at the farther range of about 22 mm for silver carp (Hypophthalmichthys molitrix) and tilapia (Oreochromis sp.) fry and 10 mm for rice field prawns. Video recording revealed three patterns of marble goby foraging behaviors. Type A showed the sit-and-wait predatory behavior which occurred to marble goby subject to 1-day starvation. The common foraging pattern was type B - hover search, which included swimming, stationary for a little while then accelerating towards fish fry. When marble goby fingerlings were under deprived condition, the foraging pattern was multiple feeding (type C), for which marble goby fingerlings crept, swam and chased prey throughout water column, attacked all prey encountered during one feeding action. It took only 2 - 5 seconds to strike silver carp fry, but 2 - 10 seconds and 3 -20 seconds to capture tilapia fry and rice field prawns, respectively. The percentage capture success of marble goby fingerlings to silver carp fry was 98.06% compared to 68.35% for tilapia fry and 11.36% for rice field prawns. It was found that the deprivation caused significant response to prey ingestion.
Keywords: Marble goby (Oxyeleotris marmorata), Feeding behavior, Prey foraging