“Life histories” is a more appropriate term than “ecotypes” to describe ocean- and stream-maturing Pacific lamprey Entosphenus tridentatus

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.

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Predicting larval metamorphosis of Pacific lamprey Entosphenus tridentatus through measurements of length and mass

Journal of Fish Biology ◽

10.1111/jfb.14436 ◽

2020 ◽

Vol 97 (3) ◽

pp. 804-816

Author(s):

Timothy A. Whitesel ◽

Michelle McGree ◽

Gregory S. Silver

Keyword(s):

Larval Metamorphosis ◽

Pacific Lamprey ◽

Entosphenus Tridentatus

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Marine biology of the pacific lamprey Entosphenus tridentatus

Reviews in Fish Biology and Fisheries ◽

10.1007/s11160-019-09578-8 ◽

2019 ◽

Vol 29 (4) ◽

pp. 767-788 ◽

Cited By ~ 9

Author(s):

Benjamin J. Clemens ◽

Laurie Weitkamp ◽

Kevin Siwicke ◽

Joy Wade ◽

Julianne Harris ◽

...

Keyword(s):

Marine Biology ◽

Pacific Lamprey ◽

The Pacific ◽

Entosphenus Tridentatus

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Occurrence of larval Pacific lamprey Entosphenus tridentatus from Japan, detected by random amplified polymorphic DNA (RAPD) analysis

Ichthyological Research ◽

10.1007/s10228-005-0276-4 ◽

2005 ◽

Vol 52 (3) ◽

pp. 297-301 ◽

Cited By ~ 10

Author(s):

Yuji Yamazaki ◽

Norio Fukutomi ◽

Norio Oda ◽

Koichi Shibukawa ◽

Yasuo Niimura ◽

...

Keyword(s):

Rapd Analysis ◽

Random Amplified Polymorphic Dna ◽

Pacific Lamprey ◽

Entosphenus Tridentatus

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Using genetic pedigree reconstruction to estimate effective spawner abundance from redd surveys: an example involving Pacific lamprey (Entosphenus tridentatus)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2016-0154 ◽

2017 ◽

Vol 74 (10) ◽

pp. 1646-1653 ◽

Cited By ~ 9

Author(s):

S.L. Whitlock ◽

L.D. Schultz ◽

C.B. Schreck ◽

J.E. Hess

Keyword(s):

Pedigree Reconstruction ◽

Spawning Ground ◽

Pacific Lamprey ◽

Entosphenus Tridentatus ◽

Mature Fish ◽

Survey Methodologies ◽

Sexually Mature ◽

Substantial Effort

Redd surveys are a commonly used technique for indexing the abundance of sexually mature fish in streams; however, substantial effort is often required to link redd counts to actual spawner abundance. In this study, we describe how genetic pedigree reconstruction can be used to estimate effective spawner abundance in a stream reach, using Pacific lamprey (Entosphenus tridentatus) as an example. Lamprey embryos were sampled from redds within a 2.5 km reach of the Luckiamute River, Oregon, USA. Embryos were found in only 20 of the 48 redds sampled (suggesting 58% false redds); however, multiple sets of parents were detected in 44% of the true redds. Estimates from pedigree reconstruction suggested that there were 0.48 (95% CI: 0.29–0.88) effective spawners per redd and revealed that individual lamprey contributed gametes to a minimum of between one and six redds, and in one case, spawned in patches that were separated by over 800 m. Our findings demonstrate the utility of pedigree reconstruction techniques for both inferring spawning-ground behaviors and providing useful information for refining lamprey redd survey methodologies.

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