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Maturation characteristics and life history strategies of the Pacific Lamprey, Entosphenus tridentatus

Canadian Journal of Zoology

By:
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DOI: 10.1139/cjz-2013-0114

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Abstract

Lampreys (Petromyzontiformes) have persisted over millennia and now suffer a recent decline in abundance. Complex life histories may have factored in their persistence; anthropogenic perturbations in their demise. The complexity of life histories of lampreys is not understood, particularly for the anadromous Pacific lamprey, Entosphenus tridentatus Gairdner, 1836. Our goals were to describe the maturation timing and associated characteristics of adult Pacific lamprey, and to test the null hypothesis that different life histories do not exist. Females exhibited early vitellogenesis – early maturation stages; males exhibited spermatogonia – spermatozoa. Cluster analyses revealed an “immature” group and a “maturing–mature” group for each sex. We found statistically significant differences between these groups in the relationships between (i) body mass and total length in males; (ii) Fulton’s condition factor and liver lipids in males; (iii) the gonadosomatic index (GSI) and liver lipids in females; (iv) GSI and total length in females; (v) mean oocyte diameter and liver lipids; and (vi) mean oocyte diameter and GSI. We found no significant difference between the groups in the relationship of muscle lipids and body mass. Our analyses support rejection of the hypothesis of a single life history. We found evidence for an “ocean-maturing” life history that would likely spawn within several weeks of entering fresh water, in addition to the formerly recognized life history of spending 1 year in fresh water prior to spawning—the “stream-maturing” life history. Late maturity, semelparity, and high fecundity suggest that Pacific lamprey capitalize on infrequent opportunities for reproduction in highly variable environments.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Maturation characteristics and life history strategies of the Pacific Lamprey, Entosphenus tridentatus
Series title:
Canadian Journal of Zoology
DOI:
10.1139/cjz-2013-0114
Volume
91
Issue:
11
Year Published:
2013
Language:
English
Publisher:
NRC Research Press
Contributing office(s):
Coop Res Unit Seattle
Description:
14 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Canadian Journal of Zoology
First page:
775
Last page:
788