American shad (Alosa sapidissima) concentrate each summer in the basins of the inner Bay of Fundy during their coastal migration. Tag returns from 6124 marked shad indicated that these fish return to every important shad spawning stream on the Atlantic coast. Ten meristic and 16 morphometric characters of shad collected from 14 rivers (range: Florida to Quebec) were used to develop linear discriminant functions (LDF). Variables which differed significantly (p < 0.05) between the sexes, year of sampling, and the time of collection during the spawning run were removed prior to LDF classification. The highest mean percent correct classification was achieved by the allocation of fish into regional groups, after classification into individual rivers, using pooled meristic and morphometric variables: 87.2% for males and 82.4% for females. The functions were then used to assign shad from a mixed populations (Cumberland Basin) to individual rivers and regions. Of these, 10.9% were assigned to rivers south of Cape Lookout, North Carolina, 38.1% to rivers between Cape Lookout and Cape Cod, 32.5% into rivers of the Bay of Fundy, and 18.5% into rivers in the Gulf of St. Lawrence. In-river tag returns were compared with LDF classification and were found to be similar.
The reproductive behavior of aquarium-held and free-living ninespine sticklebacks was studied at South Bay, Manitoulin Island, Ontario. In general their behavior resembles that of the Northwestern European Pungitius, which has been described in the literature, but several differences were discovered. The European form breeds in quiet, weedy streams, whereas the South Bay form breeds in rocky, barren, often turbulent lakeshores. The breeding males of the South Bay form have a black ventral patch that has not been described for the European form. Like Gasterosteus, the South Bay form nests on the substrate, unlike the European form, which nests in weeds. Differences in the details of nest building, agonistic, courtship, and parental behavior have been discussed in terms of adaptations to specific breeding habitats.
The agonistic responses of the male brook stickleback have been described. These displays do not follow or precede each other randomly. It is concluded that common causal factors are operating within the animal. Sequential analysis of these responses reveal that they can be related to states that vary between the tendency to attack and the tendency to flee. The fact that biting rarely occurs in territorial border encounters supports the theory that threat as a social signal evolved to accomplish spatial restriction without bodily injury.
The courtship behavior of a population of Culaea inconstans from London, Ontario, has been described in detail. Sequential analysis of the courtship of eight males for 77 half-hour periods shows that there is a sequence of behavior elements which go from pummeling to leading to showing to quivering and to fertilizing. During courtship the male shows aggressive and nest-building elements of behavior which are described as displacement activities. The courtship elements of behavior of this population differed from those described for another population from the state of New York. The differences probably represent postglacial evolution in this species.
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