8071

• UCREFRP Catalog Number: 8071
• Author: Horn, M. J. and P. C. Marsh.
• Title: Production of Razorback Sucker in a Backwater at Yuma Cove, Lake Mohave, Arizona and Nevada, 1992.
• USFW Year: 1993.
• USFW - Doc Type: Tempe, Arizona.
• Copyright Material: NO

5

METHODS

The Yuma Cove backwater was stocked on 27-28 January 1992 with ripe

adults (28 females and 60 males) captured from the adjacent Lake

Mohave shoreline (a full report on that operation is available by

request). At the time of stocking, 29% (8) of females and 88% (53)

of males were ripe.

Monitoring commenced in mid-February, and consisted initially of

sampling using hand-held spotlights, which were known to attract

the phototactic sucker larvae thereby allowing capture with fine-

mesh dip nets. Light traps, however, were experimentally shown to

be more convenient and efficient than spotlights. These traps were

thus adopted as the standard larval sampling technique (application

of this method is reviewed by Mueller et al., in preparation).

Light trapping also revealed an unanticipated density of predatory

odonate larvae in the backwater, which led to an independent,

experimental examination of their potential impact on razorback

sucker recruitment (Horn et al., in preparation). As fish grew,

seining, entanglement netting, traps, and other techniques were

variously applied in attempt to collect adequate samples to assess

cohort status.

Fish marking (right pectoral fin clip) to enable population

abundance estimation was initiated on 16 June and continued until