Comparison of Mark Retention and Survival of Sea Lamprey Larvae Marked by Pigment Injection and Tail Clipping: Comparison of 3-Trifluoromethyl-4-Nitrophenol (TFM) Toxicities to Sea Lampreys, Rainbow Trout, and Mayfly Nymphs in Continuous and Interrupted -

摘要

Both mark retention and survival were similar for sea lamprey (Petromyzon marinus) larvae marked by either a subcutaneous injection of pigment or a tail clip. Survival of all marked and control larvae exceeded 86% alter 14 wk. Use of the vent to speed needle insertion into the caudal sinus did not affect survival. Tail clips are recommended for population estimates where only one mark is needed because they are faster to apply and less visible to predators and collectors than injected pigments. Pigment injection is preferred when more than one mark is required for a stream system because larvae from different treatments can be identified by pigment color or injection site. Flow-through tests with 12DGC Lake Huron water were used to examine the toxicity of 3-trifluoromethyl-4-nitrophenol (TFM) to larval sea lampreys (Petromyzon marinus), fry of rainbow trout (Oncorhynchus mykiss), and nymphs of burrowing mayfly (Hexagenia limbata). The objective of this study was to evaluate and compare the effectiveness of a single, continuous 9-h exposure to TFM with two exposures (totaling 9 h) of TFM that were interrupted by 12 h or 22 h of no exposure. Two exposures to TFM interrupted for 12 h were as effective at killing sea lampreys as a single, continuous 9-h exposure, but the toxicity of TFM to sea lampreys sometimes declined when the interruption period was increased to 22 h. The toxicity of TFM to rainbow trout did not differ significantly among the continuous 9-h exposure and two tests where exposures were interrupted for either 12 h or 22 h.