Internal dynamics and the interrelations of fish in schools

SummaryThe three-dimensional structure of schools of saithe (Pollachius virens) and the interactions between individuals over time were analyzed in 12,240 frames of videotape sampled at 2.7 Hz. Time series analyses of the interactions between identified individuals allowed testing of assumptions of anonymity vs. leadership in schools and investigation of the transfer of information between individuals by which collective decisions are made. Results include the following:1.Saithe match changes in both swimming direction and speed of their neighbors but correlations are greater for swimming speed. Average speed of the school does not greatly affect correlations between neighboring fish although the reaction latencies may be somewhat increased. As shown previously (Partridge et al. 1980) nearest neighbor distance (NND) decreases with increasing school velocity.2.Saithe simultaneously match the headings and swimming speeds of at least their first two nearest neighbors within the school (NN1 and NN2). Partialling out the correlation between a fish's neighbors demonstrates that a fish's correlation to his second nearest neighbor (NN2) is not simply a transitive function of mutual correlation between the NN1 and NN2.3.Several sources of individual variation in schooling performance were examined. In all respects except one, that of preferred positions within the school, saithe showed no individual differences, i.e., some were not “better schoolers” than others. Although fish in the school differed in length by up to a factor of 2.5, no size related effects in NND or nearest neighbor positioning were found.4.Single Linkage Cluster Analysis (SLCA) of the cross-correlations of fishs' swimming speeds and directions demonstrated quantitatively the existence of subgroups within schools if they contain more than 10–11 members. Subgroups acting more-or-less independently in terms of short term variations in speed and direction nonetheless remained within the school as a whole and were not often apparent to observers since members of one group interdigitated with those of another. How individuals know to which subgroup they belong remains unanswered.

[1]  W. Bateson,et al.  The Sense-organs and Perceptions of Fishes; with Remarks on the Supply of Bait , 1890, Journal of the Marine Biological Association of the United Kingdom.

[2]  A. Parr.  A contribution to the theoretical analysis of the schooling behavior of fishes , 1927 .

[3]  Certain effects in the habits of schooling fishes, as based on the observation of Jenkinsia. American Museum novitates ; no. 382 , 1929 .

[4]  E. Selous.  Thought Transference (or What ?) in Birds , 1932, Nature.

[5]  An Experiment on the Shoaling Behaviòur in Fish , 1950 .

[6]  Charles M. Breder.  Studies on the structure of the fish school. Bulletin of the AMNH ; v. 98, article 1 , 1951 .

[7]  C. Breder.  Equations Descriptive of Fish Schools and Other Animal Aggregations , 1954 .

[8]  M. Keenleyside,et al.  Some Aspects of the Schooling Behaviour of Fish , 1955 .

[9]  S. Siegel,et al.  Nonparametric Statistics for the Behavioral Sciences , 2022, The SAGE Encyclopedia of Research Design.

[10]  Sir James Gray.  How Fishes Swim , 1957 .

[11]  R. Bainbridge,et al.  The Speed of Swimming of Fish as Related to Size and to the Frequency and Amplitude of the Tail Beat , 1958 .

[12]  S. Dijkgraaf.  THE FUNCTIONING and SIGNIFICANCE OF THE LATERAL‐LINE ORGANS , 1963, Biological reviews of the Cambridge Philosophical Society.

[13]  J. Hunter,et al.  Net Avoidance Behavior of Carp and Other Species of Fish , 1964 .

[14]  K. John.  Illumination, Vision, and Schooling of Astyanax mexicanus (Fillipi) , 1964 .

[15]  C. Breder.  Vortices and fish schools , 1965 .

[16]  H. A. Baldwin,et al.  Methods for measuring the three-dimensional structure of fish schools. , 1965, Animal behaviour.

[17]  J. Hunter,et al.  Procedure for Analysis of Schooling Behavior , 1966 .

[18]  J. Gower,et al.  Minimum Spanning Trees and Single Linkage Cluster Analysis , 1969 .

[19]  J. Hunter,et al.  Communication of velocity changes in jack mackerel (Trachurus symmetricus) schools , 1969 .

[20]  J. Hunter,et al.  Some Aspects of the Organization of Fish Schools , 1970 .

[21]  T. Postelnicu,et al.  Sokal, R. R., and I. J. Rohlf: Biometry. W. H. Freeman and Company, San Francisco 1969, XXI + 776 S., 89 Abb., 56 Tab., Preis 126/— , 1970 .

[22]  J. R. Nursall.  Some Behavioral Interactions of Spottail Shiners (Notropis hudsonius), Yellow Perch (Perca flavescens), and Northern Pike (Esox lucius) , 1973 .

[23]  D. V. Radakov.  Schooling in the ecology of fish , 1973 .

[24]  C. S. Wardle,et al.  Limit of fish swimming speed , 1975, Nature.

[25]  R. Muzinić.  On the shoaling behaviour of sardines (Sardina pilchardus) in aquaria , 1977 .

[26]  Brian L. Partridge,et al.  A low-cost interactive coordinate plotter , 1977 .

[27]  C. S. Wardle.  Effects of size on the swimming speeds of fish , 1977 .

[28]  Behavioural Studies on Schooling of Fishes II : Leading-Following Relationship of the Immature Yellowtail, Seriola quinqueradiata Temminck et Schlegel in Captivity , 1978 .

[29]  J. Murray,et al.  Scale Effects in Animal Locomotion. , 1978 .

[30]  Behavioural Studies on Schooling of Fishes I. : Leading-Following Relationship of the Young Golden Trevally, Caranx speciosus (Forsskal) in Captivity , 1978 .

[31]  T. Pitcher,et al.  Sensory information and the organization of behaviour in a shoaling cyprinid fish , 1979, Animal Behaviour.

[32]  T. Pitcher,et al.  Fish school density and volume , 1979 .

[33]  C. Levings,et al.  Energy flow and population dynamics of the barnacle Balanus glandula , 1979 .

[34]  T. Pitcher,et al.  Evidence against a hydrodynamic function for fish schools , 1979, Nature.

[35]  B. Partridge,et al.  The effect of school size on the structure and dynamics of minnow schools , 1980, Animal Behaviour.

[36]  G. Lauder.  How Fishes Swim , 1984 .

[37]  G. Helfman,et al.  Patterns of community structure in fishes: summary and overview , 1978, Environmental Biology of Fishes.

[38]  T. Pitcher,et al.  The three-dimensional structure of fish schools , 1980, Behavioral Ecology and Sociobiology.

[39]  T. Pitcher,et al.  The sensory basis of fish schools: Relative roles of lateral line and vision , 1980, Journal of comparative physiology.

[40]  L. Dill,et al.  The three-dimensional structure of airborne bird flocks , 1978, Behavioral Ecology and Sociobiology.