Identification of larval Pacific lampreys (Lampetra tridentata) , river lampreys (L. ayresi) , and western brook lampreys (L. richardsoni) and thermal requirements of early life history stages of lampreys. Annual report 2001

Meeuwig, M.H.; Bayer, J.M.; Seelye, J.G.; Reiche, R.A.

BPA Report DOE BP uary; 00004695-1: Unpaginated

2002


Accession: 022798727

Download citation:  
Text
  |  
BibTeX
  |  
RIS

Article/Abstract emailed within 1 workday
Payments are secure & encrypted
Powered by Stripe
Powered by PayPal

Abstract
Two fundamental aspects of lamprey biology were examined in order to provide tools for population assessment and determination of critical habitat needs of Columbia River Basin lampreys (the Pacific lamprey, Lampetra tridentata, and the western brook lamprey, L. richardsoni). In particular: 1) we examined the usefulness of current diagnostic characteristics used for identification of larval lampreys, specifically pigmentation patterns, and collected material for development of meristic and morphometric descriptions of early life stages of lampreys, and 2) we examined the effects of temperature on development and survival of early life stages of Columbia River Basin lampreys. In 1999 thirty-one larval lampreys (ammocoetes) were collected from locations throughout the Columbia River Basin and transported to the Columbia River Research Laboratory. They are being examined and identified to species at approximately sixweek intervals until they metamorphose and their identity can be confirmed by dentition patterns. Currently, these lampreys have been sampled 14 times, and two individuals have metamorphosed allowing confirmation of species identification. Of the lampreys that have not metamorphosed, only one has been inconsistently identified (Pacific lamprey 83% of sampling events and western brook lamprey 17% of sampling events)suggesting that pigmentation patterns do not change appreciably through time. Also, in 2001 we artificially spawned Pacific and western brook lampreys in the laboratory and collected 150 Pacific lamprey and 140 western brook lamprey embryos and 110 Pacific lamprey and 70 western brook lamprey prolarvae/larvae for meristic and morphometric description. Pacific and western brook lampreys were artificially spawned and resulting progeny were reared at the Columbia River Research Laboratory at 10° C, 14° C, 18° C, and 22° C. Temperature had an overall significant effect on survival from fertilized egg to 50% hatch with increasing survival from 10° C to 18° C and decreased survival at 22° C for Pacific (F3,28=74.10, P<0.0001) and western brook (F2,24=66.50, P<0.0001) lampreys. Temperature had an overall significant effect on survival from fertilized egg to the time when prolarvae had assimilated 50% of their yolk reserves with increasing survival from 10° C to 18° C and decreased survival at 22° C for Pacific (F2,21=53.00, P<0.0001) and western brook (F2,24=70.16, P<0.0001) lampreys. Based on survival data, the occurrence of embryonic abnormalities, and the occurrence of abnormalities at 50% yolk assimilation, the optimal temperature for development of early life stage Pacific and western brook lampreys appears to be approximately 18° C.