Distribution and ecology of lampreys Lethenteron spp. in interior Alaskan rivers
Citation
T. M. Sutton. 2016. Distribution and ecology of lampreys Lethenteron spp.
in interior Alaskan rivers. Journal of Fish Biology (2017) 90, 1196–1213
doi:10.1111/jfb.13216, available online at wileyonlinelibrary.com
Summary
This study describes phenetic characteristics and examines the life history of anadromous Arctic lamprey Lethenteron camtschaticum and freshwater-resident Alaskan brook lamprey Lethenteron alaskense in two tributaries of the middle Yukon River, Alaska. Larval lampreys could not be identified to species using pigmentation density patterns or trunk myomere counts, but adults could be identified to species based on colouration, body size and oral-disc dentition. Although larvae were patchily distributed in both rivers, there was a greater proportion of sample locations where Lethenteron spp. were absent in upper reaches than in middle and lower reaches. Relative abundance, density and median and maximum total length (LT) of larvae were [...]
Summary
This study describes phenetic characteristics and examines the life history of anadromous Arctic
lamprey Lethenteron camtschaticum and freshwater-resident Alaskan brook lamprey Lethenteron
alaskense in two tributaries of the middle Yukon River, Alaska. Larval lampreys could not be identified
to species using pigmentation density patterns or trunk myomere counts, but adults could be identified
to species based on colouration, body size and oral-disc dentition. Although larvae were patchily
distributed in both rivers, there was a greater proportion of sample locations where Lethenteron spp.
were absent in upper reaches than in middle and lower reaches. Relative abundance, density and
median and maximum total length (LT) of larvae were highly variable among sampling locations.
Current velocity, substratum type and coarse woody debris were most strongly correlated with larval
Lethenteron spp. density; velocity and substratum size was negatively correlated, whereas woody
debris was positively correlated. Water depth, dissolved oxygen levels and specific conductance
did not influence habitat selection. Length–frequency distributions, diet composition (organic
detritus≥98%), assimilation efficiency (>70%) and gut fullness (<0·2mg diet ash-free dry mass)
were similar for larvae, regardless of river or sampling location. These results increase understanding
of Lethenteron spp. biology and ecology in interior Alaska drainages and add to the existing literature
on Lethenteron spp. life history.
