Group foraging by a stream minnow: shoals or aggregations?

Freeman, Mary C.; Grossman, Gary D.

doi:10.1016/0003-3472(92)90050-j

“…Date foraged in one small area of pool 1 during December, and of pool 2 during October and December, despite habitat conditions similar to August, when foragers were relatively widely dispersed. Analyses of group dynamics (Freeman & Grossman 1992b) also provided evidence of greater attraction among foragers in autumn. However, both the timing and degree of increased grouping varied among pools, suggesting that increased contagion was not a fixed response to lower water temperatures or some other seasonal change.…”

Section: Discussionmentioning

confidence: 93%

“…Date feed on drifting invertebrates and may forage solitarily or in groups. Analyses of group dynamics, however, revealed only weak evidence of social attraction (Freeman & Grossman 1992b). We thus hypothesized that forager dispersion primarily depends on the availability of suitable foraging habitat, and we tested for correlations between date dispersion and total habitat availability.…”

Section: Introductionmentioning

confidence: 99%

Effects of habitat availability on dispersion of a stream cyprinid

Freeman

¹

,

Grossman

²

1993

Self Cite

View full text Add to dashboard Cite

“…They forage both solitarily and in groups, and occasionally display intraspecific aggression (Grossman & Freeman, 1987;Freeman & Grossman, 1992;Rincó n & Grossman, 1998). In the present study, interindividual differences in aggressive behaviour were examined and the effects of fish size on aggressiveness and the outcome of contests quantified.…”

Section: Introductionmentioning

confidence: 94%

“…As the relationship between intraspecific aggression and access to food resources was being investigated, behavioural observations began 3 min after a delivery of food into the stream. During the 3 min of observations on each specimen, the number of food pellets captured, the number of times the focal fish displaced another fish, the number of times the focal fish was displaced by another fish, the number of chases performed, and the number of chases received were recorded using the methods of Freeman & Grossman (1992). Depending on the particular analysis, behavioural events were expressed as either number of events 3 min 1 , or as total number of events per treatment.…”

Section: Observationsmentioning

confidence: 99%

“…In temperate streams, drift feeding cyprinids often dominate fish assemblages (Jenkins & Burkhead, 1994;Matthews, 1998;Moyle & Cech, 1999) and they are also common in both African and Asian streams and rivers (Matthes, 1964;Moyle & Senanayake, 1984;Skelton, 1993). Although there is a general lack of information on aggressive behaviour in cyprinids, there is some evidence that it may influence their use of trophic and spatial resources (Symons, 1975;Reeves et al, 1987;Freeman & Grossman, 1992;Katano, 1996). Consequently, the dynamics of intraspecific aggression in rosyside dace Clinostomus funduloides Girard, a drift-feeding stream cyprinid native to portions of the eastern U.S.A., was quantified.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intraspecific aggression in rosyside dace, a drift‐feeding stream cyprinid

Rincón

¹

,

Grossman

²

2001

Journal of Fish Biology

View full text Add to dashboard Cite

Individual rosyside dace Clinostomus funduloides in a semi-natural, artificial stream displayed substantial differences in their aggressiveness and could be classified as: (1) non-aggressive (NA, 18 of 30 rosyside dace), (2) moderately aggressive (MA, 9 of 30) and (3) highly aggressive (HA, 3 of 30). Rosyside dace groups, however, did not exhibit linear dominance hierarchies and fish size was only weakly correlated with the number of aggressive acts performed per individual. Small rosyside dace (<56 mm L F ) were always non-aggressive, but larger fish were present in all three aggression classes. The difference in size between the contestants was significantly, although not very strongly, correlated with the probability of winning an agonistic interaction (r 2 =0·39). Aggressive rosyside dace may have ultimately gained higher fitness than less aggressive ones. HA individuals occupied the upstream-most position within foraging groups significantly more often than other rosyside dace. This location should be the most profitable one because its occupant will be the first to encounter prey. HA rosyside dace also occupied significantly higher focal velocities that were closer to energetic optima than MA and NA ones. They also had greater foraging rates and were less solitary than less aggressive fish, but these differences only were significant at the P=0·066 and P=0·081 level, respectively. Finally, HA fish performed significantly more aggressive acts and feedings backwards than other individuals. Despite these differences, the effects of intraspecific aggression in rosyside dace appeared less substantial than those that have been observed in stream salmonids. 2001 The Fisheries Society of the British Isles

show abstract

Intraspecific aggression in rosyside dace, a drift-feeding stream cyprinid

Rincó¹

2001

Journal of Fish Biology

View full text Add to dashboard Cite

Individual rosyside dace Clinostomus funduloides in a semi-natural, artificial stream displayed substantial differences in their aggressiveness and could be classified as: (1) non-aggressive (NA, 18 of 30 rosyside dace), (2) moderately aggressive (MA, 9 of 30) and (3) highly aggressive (HA, 3 of 30). Rosyside dace groups, however, did not exhibit linear dominance hierarchies and fish size was only weakly correlated with the number of aggressive acts performed per individual. Small rosyside dace (<56 mm L F ) were always non-aggressive, but larger fish were present in all three aggression classes. The difference in size between the contestants was significantly, although not very strongly, correlated with the probability of winning an agonistic interaction (r 2 =0·39). Aggressive rosyside dace may have ultimately gained higher fitness than less aggressive ones. HA individuals occupied the upstream-most position within foraging groups significantly more often than other rosyside dace. This location should be the most profitable one because its occupant will be the first to encounter prey. HA rosyside dace also occupied significantly higher focal velocities that were closer to energetic optima than MA and NA ones. They also had greater foraging rates and were less solitary than less aggressive fish, but these differences only were significant at the P=0·066 and P=0·081 level, respectively. Finally, HA fish performed significantly more aggressive acts and feedings backwards than other individuals. Despite these differences, the effects of intraspecific aggression in rosyside dace appeared less substantial than those that have been observed in stream salmonids. 2001 The Fisheries Society of the British Isles

show abstract

Group foraging by a stream minnow: shoals or aggregations?

Cited by 23 publications

References 34 publications

Effects of habitat availability on dispersion of a stream cyprinid

Effects of habitat availability on dispersion of a stream cyprinid

Intraspecific aggression in rosyside dace, a drift‐feeding stream cyprinid

Intraspecific aggression in rosyside dace, a drift-feeding stream cyprinid

Contact Info

Product

Resources

About