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Effects of Two Electrofishing Currents on Captive Ripe Razorback Suckers and Subsequent Egg‐Hatching Success
Author(s) -
Muth Robert T.,
Ruppert Jack B.
Publication year - 1996
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(1996)016<0473:eoteco>2.3.co;2
Subject(s) - electrofishing , hatching , sucker , biology , zoology , fish <actinopterygii> , fishery , anatomy
In the laboratory, we assessed direct effects of electroshock by two types of square‐wave pulsed DC in homogeneous fields of 1.0 peak volts per centimeter on ripe razorback suckers Xyrauchen texanus and evaluated subsequent egg‐hatching success. Four males and four females were exposed for 10 s to a simple 60‐Hz (24% duty cycle) current, and four males and three females were subjected for 10 s to a complex pulse pattern of three 240‐Hz, 2.6‐ms pulses delivered at 15 Hz (12% duty cycle). All shocked fish expelled some gametes during treatment. No external hemorrhages were observed, but X‐ray and necropsy examinations revealed injuries associated with the spinal column in two males and two females subjected to the 60‐Hz current and one female exposed to the complex pulse pattern; no injuries were observed in the four control fish (two males and two females). Mean percent egg hatch for fish shocked by either current was significantly lower ( P ≤ 0.05) than that for control fish. Differences in hatching success between treatment currents were not significant. Electrofishing could adversely affect razorback sucker populations by injuring adults and reducing their reproductive success.