Meristic variation in the threespine stickleback, Gasterosteus aculeatus L., in eastern Canadian waters

• Published in: Canadian Journal of Zoology
• Main Authors: Garside, E. T., Hamor, T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1973
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Pacific; Newfoundland
• Online Access: http://dx.doi.org/10.1139/z73-079; http://www.nrcresearchpress.com/doi/pdf/10.1139/z73-079

Samples of threespine stickleback, Gasterosteus aculeatus L., collected from several areas of Newfoundland and Nova Scotia, and single sites from Iles de la Madeleine, Quebec, and eastern Lake Ontario, were analyzed for variation in numbers of anterior lateral plates and vertebrae. Counts of vertebrae varied from 28 to 35 and mean counts from 30.3 to 33.4, without being related to any obvious geographic gradients. Trunk and caudal segments of the vertebral column had about the same degree of variation. Counts of lateral plates exclusive of ossicles of the caudal keel ranged from 0 to 31 with a range of means from 1.6 to 24.7. Incomplete development of potential plate number and absence of caudal keels were observed in 1st-year individuals. These results are discussed in relation to information about this species complex from populations of Pacific North America and Europe.