7014

• UCREFRP Catalog Number: 7014
• Author: Valdez, R. A. and A. Wasowicz.
• Title: Non-Lethal Stomach Pumping Technique To Recovery Gut Contents of Roundtail Chub ‎(
• USFW Year: 1992.
• Copyright Material: NO

4

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

RESULTS

Efficiency of Stomach PumDine Method

Of the 20 roundtail chub subjected to the stomach pump, measurable amounts of food were
flushed from eight, eight others yielded only traces of algae or unidentifiable debris, and four
contained no food. Most of the flushed material appeared to be insects, some mixed with algae. In
all cases, gut contents were flushed from the anal vent with no apparent ill effect on the fish.
Material from the gut was evacuated with relatively little water pressure, indicating that there was
little physical stress to the intestine and intestinal lining.

This stomach pump method was 100% efficient, based on examination of the residual gut
contents following flushing. No measurable amount of food was found in any of the pre-flushed
digestive tracts.

Although the fish were not held for an extended time period, no ill effects were observed for
any individuals subjected to stomach pumping. The anesthesia MS-222 (tricane methane sulfonate)
was use only to eutharnze the fish following testing. MS-222 was not used to sedate the fish
subjected to stomach pumping, to determine if sedation is necessary for this process. We concluded
that the fish could be processed without sedation, and therefore eliminate the need to use MS-222
on the endangered humpback chub.

Examination of the Phvarvneeal Teeth

Results of this Study

No evidence of broken phyaryngeal teeth was found in the fish subjected to stomach pumping.
A nearly equal number of control and test fish contained loose phyaryngeal teeth that appeared to
be in the process of being shed or in the process of ankylosis (anchoring on the arch) (Table 3).
These teeth appeared to be in different stages of formation and had soft rounded pulpy bases. Some
of these loose teeth were in alignment with the pharyngeal arch while others were still in the
epithelial tissue adjacent to the arch.

The tubing inserted into the esophagous of the fish was closely examined for marks indicating
contact with the hooked pharyngeal teeth. No evidence of contact between the inlet tube and the
pharyngeal teeth was observed.

The mucosal tissue around the pharyngeal teeth precluded counts of teeth by row, and so only
the total number of teeth on each side was recorded. Roundtail chub and humpback chub typically
have a pharyngeal tooth formula of 2,5-4,2 (Miller 1946), but these are extremely variable (Holden
1968). The bilateral asymmetry, with higher counts of pharyngeal teeth on the left arch, is common
among North American cyprinids (Eastman and Underhill 1973).

About Pharvneeal Teeth

Pharyngeal teeth are one of three kinds of teeth found in bony fishes (Osteichthyes). Jaw
teeth and mouth (palatine, vomerine, etc.) teeth are the other two types. Pharyngeal teeth are the
only teeth of minnows (Cyprinidae) and suckers (Catstomidae). These are located deep in the