In:
Canadian Journal of Zoology, Canadian Science Publishing, Vol. 68, No. 6 ( 1990-06-01), p. 1202-1208
Abstract:
Previous studies of migratory populations of sticklebacks (Pisces: Gasterosteidae) have been exclusively limited to their biology on the spawning grounds during the spring breeding season. In 1985 and 1986, we studied the ecology of the threespine stickleback (Gasterosteus aculeatus) in three subhabitats of the middle St. Lawrence estuary before, during, and after the breeding season: (i) the open waters of the estuary, (ii) a series of intertidal salt marsh pools, and (iii) two tidal rivers (Rivière des Vases and Rivière Trois-Pistoles). In spring, our catch data in the various subhabitats showed that adults moved from the open waters of the estuary towards the tidal rivers and tide pools. Catches of adults in all subhabitats subsequently declined, whereas the young of the year (age 0+) became increasingly abundant. In this area, G. aculeatus live for 2 years and are physiologically capable of breeding during their first summer as adults. However, we found age-related differences in habitat use between the two adult year classes. Age 1+ fish were never more abundant than age 2+ fish in Rivière des Vases, in the tide pools, and in the open waters of the estuary, whereas age 1+ fish were more abundant than age 2+ fish in Rivière Trois-Pistoles. Throughout the breeding season, gonadosomatic indices of female G. aculeatus were the same for the two age groups. Total lengths of age 0+ fish captured in the various subhabitats suggest that the major spawning period is limited to May and June. Age 0+ fish do not leave the tide pools for the open waters of the estuary before having attained a certain minimum size.
Type of Medium:
Online Resource
ISSN:
0008-4301
,
1480-3283
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1990
detail.hit.zdb_id:
1490831-1
SSG:
12
