Philip J. Turk | Geology Reports

USGS2011

Available benthic habitat type may influence predation risk in larval lampreys

Population declines of lamprey species have largely been attributed to habitat degradation, yet there still remain many unanswered questions about the relationships between lampreys and their habitats ( Torgensen & Close 2004 ; Smith et al. 2011 ). One scarcely researched area of lamprey ecology is the effect of predation on lampreys ( Cochran 2009 ). Specifically, the influence of available habitat on predation risk has not been documented for larval lampreys but may be important to the management and conservation of lamprey populations.

West Virginia↗

USGS2011

Selection and preference of benthic habitat by small and large Ammocoetes of the Least Brook Lamprey (Lampetra aepyptera)

In this laboratory study, we quantified substrate selection by small (<50 mm) and large (100–150 mm) ammocoetes of the least brook lamprey ( Lampetra aepyptera ). In aquaria, ammocoetes were given a choice to burrow into six equally-available substrate types: small gravel (2.360–4.750 mm), coarse sand (0.500–1.400 mm), fine sand (0.125–0.500 mm), organic substrate (approximately 70% decomposing leaves/stems and organic sediment particles, and 30% silt and fine sand), an even mixture of silt, clay, and fine sand, and silt/clay (<0.063 mm). Fine sand was selected with a significantly higher probability than any other substrate. Fine sand habitat is limited in many streams, in part owing to geology, but also as a result of channelization and excessive silt/clay sedimentation, which is a conservation concern. Our results indicate that ammocoetes of least brook lampreys are habitat specialists that prefer fine sand habitat. Hence, availability of fine sand habitat may limit distributions and population sizes.

Environmental Biology of Fishes↗