9432 ‎(2)‎

• UCREFRP Catalog Number: 9432
• Author: Modde, T. and M. Fuller.
• Title: Feasibility of Channel Catfish Reduction in the Lower Yampa River.
• USFW Year: 2002.
• USFW - Doc Type: Vernal.
• Copyright Material: NO

Table. C.1. Surgical techniques employed to implant Colorado pikeminnow with
LOTEK® radiotags during the Redlands fish passageway evaluation,
1996-1999 (Burdick 2000b).
Following capture with electrofishing, by trammel or trap nets, surgery
occurred in a riverside setting. Fish were then held in a holding tank with 0.5%
salt (by weight) solution to reduce stress and assist the fish's osmoregulation.
Fish were anesthetized with Finquel°, a brand of tricaine methanesulfonate (MS-
222), at a concentration of about 100-200 mg/l for about 2-4 min, or until the
fish lost equilibrium. Fish were then transferred to an operating table where
either fresh river water or anesthetized river water was continually passed over
the fish's gills to provide oxygen and to keep the body moist. Gill opercular
rate was maintained at about one per five seconds. Fish were oriented ventral-
side up so that the internal organs would gravitate dorsally to reduce the
likelihood of severing internal organs with surgical instruments upon entering
the peritoneal cavity. A 30-40 mm long incision, was made about 15-25 mm lateral
to the midline (linea alba), and slightly anterior to the pelvic fin. To
accommodate the trailing, external antenna, a second incision, 5-8 mm-long, was
made ventral, about 5-10 mm posterior from the pelvic fin and about 10 mm lateral
to the midl ine to. provide an exit for the antenna. A stainless steel scalpel and
toothed forceps aided in making the incisions through the ventral musculature.
Once initial entry had been gained to the peritoneal cavity for the primary
incision, a grooved director was inserted in the incision opening which aided in
protecting the internal organs from accidently being damaged or cut by the
scalpel. A curved avian feeding tube facilitated positioning the external
antenna. The feeding tube (17-cm long), hollow with a blunt, bulbous end, was
first inserted through the secondary incision under (dorsal to) the pelvic girdle
and then pushed anterior where it exited the primary incision. The external
antenna was then threaded into the bulbous end and completely through to the
female luer hub of the tube. The tube and antenna were then both pulled
posteriorly through the exit incision. The tube provided a rigid frame in which
the flaccid external antenna could be threaded underneath the pelvic girdle from
the primary to secondary incision within seconds that expedited this portion of
the surgery and minimized tissue trauma. Lastly, the transmitter was inserted
and positioned dorsal to the primary incision. The incisions were closed with
either Ethicon@ absorbable or nonabsorbable sutures (3-0; FS-1 cutting needle)
that were triple-tied, individual surgical knots. Usually, five to seven sutures
were needed to close the primary incision depending on the length of transmitter
implanted; two to three were used to close the secondary incision. Sterile
saline was used to wash the fish's ventral musculature in the immediate area of
the primary and secondary incisions. Gentamicin sulfate (100 mg/ml), a wide-
spectrum antibiotic, was injected interperitoneally in radiotagged fish
immediately following surgery at 0.5 ml/kg of fish body weight. Surgical tools
were immersed in 100% alcohol afield. Wetted cotton toweling was used to
surround the fish to keep the fish's skin moist and aid in supporting the fish's
body. The surgical process required approximately 7-10 minutes. Following
surgery, fish were allowed to recover in fresh river water from the anesthetic.
Fish were released when they regained their motor skills.
C-1