7978

• UCREFRP Catalog Number: 7978
• Author: Tyus, H. M.
• Title: Chemoreception, Imprinting, and Propagation of Colorado Squawfish and Razorback Sucker
• USFW Year: 1992
• USFW - Doc Type: a Plan of Study
• Copyright Material: YES

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by releasing imprinting chemicals (and control water) during the anticipated
spawning period.

Response of the imprinted fish to suitability of the attractant and various
habitats would be monitored by recaptures.

H5: Colorado squawfish and razorback suckers recognize odors from reproductive
byproducts and use them to locate specific sites for egg deposition.

Task: Determine if reproductive by-products can be used to attract fish in
lieu of using a synthetic chemical.

Methods: Obtain biological waste-products (egg cases, feces, et ) from
hatchery-reared fish, and place these in selected spawning locatio s. Monitor
the location by capturing fish during the spawning season. This co ld be done
in the presence or absence of other cues (HSOB or synthetic compou ds)
depending on study design.

Morphology

It is important to determine temporal development of functional I receptors
used in olfaction to determine the timing associated with imprinting.
Therefore it is necessary to determine the comparative functional ~orphology
of sensory organ development and their function. r

Also there are accessory organs involved with reproduction in i' th species:
In the Colorado squawfish, breeding tubercles are hard, horny structures that
may have a tactile function in breeding, and razorback sucker tubercles are
soft and fleshy organs that may be involved with secretions of at ractant
odors.

H6: Functional receptors used in olfaction develop at an early st ge in
Colorado squawfish and razorback sucker
Task: Determine the development of olfactory sensory organs

Methods: Obtain a series of ontogenic stages for both species tnd
determine structures microscopically.

Task: Determine neuroanatomy of sensory system: when do connections become
functional (i.e. "turned on"). I

Methods: Obtain a series of ontogenic stages for both species ~nd
determine structures microscopically. I

H7: Breeding tubercles are important reproductive organs that ma be involved
in attracting mates and influence the successful completion of s awning.

Task: Evaluate the role of tubercles in reproduction.

Methods: Obtain tissues from sexually-mature fish and examine these
structures microscopically to determine possible function.

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