7146

• UCREFRP Catalog Number: 7146
• Author: Hubbs, C. L. and R. R. Miller
• Title: Hybridization in Nature Between the Fish Genera
• USFW Year: 1953
• Copyright Material: YES

Hybridization between Catosfollw.s and Xyrallclwll 'l15

vary little in proportions throughout its range, the graphs for ~hat
genus are based on specimens from all parts of the Colorado Rlv~r
system. The data for Catostomus latipinnis were taken from speCI-
mens from the upper Colorado River system in Colorado (mostly)
and in northern Utah, at and near the places where the hybrids were

TABLE V

MEASUREMENTS OF CATos'rOMUS LATtPINNIS, HYBRIDS, AND XYUAUCHEN TEXAN US

Actual measurements are given for the eight hybrids, along with the average
measurements of. the parental species at the same sizes, determined graphically (Figs.
1-2). The hybrids and most of the specimens of both parental species were measured
by Hubbs; most measurements of the young of Xyrauchen texanus were taken by
Miller. We followed the methods recommended by Hubbs and LagleI' (1947 pp.
13-15, figs. 2-5). Precision dial calipers were used in measuring the smaller pa;ts.

Measurement

Standard length ........ 101. 7 256

Dimension, in mm.

385'

186 391 442
-- -.- -
6.0 77.0 85.6
8.2 78.0 92.8
1.3 102.5 103.6
.t.8 65.5 74.1
ij.7 70.0 78.3
'7.5 88.6 100.0
7.4 27.7 31.4
L.9 29.6 33.7
1.9 34.3 38.7
r .3 38.0 45.0
1.4 3.1. B 33.2
),2 20.6 24.4
..5 19.8 23.3
1.4 22,4 24.9
.8 25.3 29.2
..81 1.82 2.1
.46 2.65 . 2.56
i.62 6.75 8.1
,.76 5.90 6.69
.04 6.UO 7.54
;.28 6.38 7.2
1.2 68.9 77.8
.1 74.7 87.2
1.1 81.9 91.0
.'.0 17.3 .. . t
1.7 13. ~l . ..
1.5 18.75 .. .
52 52 52
70 64 75
23 128 120

collected. The actual measurements of the hybrids are plotted on
the same graphs. The growth lines for the parental species were
drawn by inspection. Several types of curves} some not readily
subject to conventional analysis through logarithmic transformations,
are obviously represented.

Body depth
C. latipinnis. ......... 22.0
Hy brid .............. 24.7
X.texanus ...........28.6
Depth through pectoral in-
sertion
C. latipinnis. . . . . . . . . .
Hybrid ..............
X. texanua ...........
Caudal-peduncle depth
C. latipinnis. . . . . . . . . .
Hybrid ..............
X. texanus ...........
Lips, overnlllcngth (A)*
C. llliipinnia. . . . . . . . . .
lTybrid ..............
X. ieXllnllS ...........
Gape width (B)
C. llltipinnis. . . . . . . . . .
Hybrid ..............
X. texanlls ...........
Separation, lower lipst
C. latipinnis. . . . . . . . . .
Hybrid ..............
X. texanus ...........
Gillraker, length of longest
C. latipinnis. . . . . . . . . .
Hybrid ..............
X. texanU8 ...........
Dorsal fin, length of base
C. latipinnis. . . . . . . . . .
Hybrid ..............
X. texanus ...........
Interpelvic space
C. latipinnis. . . . . . . . . .
Hybrid ..............
X. texanU8 " . . . . .. . . .
Ratio, B/ A (Fig, 8)
C.latipinnis. .........
Hybrid ..............
X. texanus ............

53.0
61.3
70.7

379

384

64.4 64.6
71.7 71.4
87.0 87.2
27.2 27.3
30.1 30.3
33.7 33.8
37.0 87.2
32.2 31.7
20.0 20.1
19.4 19.5
23.8 19.2
24.6 24.7
1.80 1.81
2.55 8.63
6.58 6.60

5.74
5.80
6.24

67.8
73.1
80.7

16.9
14.1
18.4

52
74
123

-9

75.0 75.7 75.8 7
92.3 82.5 87.5 8
99.7 100.7 101.0 10

-8

214

LENGTH OF
7- LONGEST

6
7
8

2'
3
3:

5

17.3 43.8 63.6
19.9 47.65 77.8
22.5 57.7 85.8
6.65 17.8 26.9
8.2 20.3 28.9
9.1 22.7 33.3
7.1 21.7 36.8
6.4 18.6 28.4
5.2 12.4 19.7
4.9 12.2 19.1
6.0 13.15 19.7
6.1 15.2 24.2
0.46 1.16 1.77
0.54 ~.80 4.75
1.14 3.80 6.44
1.26 3.56 5.66
1.42 3.66 5.75
1.69 4.33 6.16
18.8 45.6 67.0
22.2 54.3 78.1
26.1 57.1 79.8
2.6 9.3 16.5
3.2 12.45 12.8
4.1 11.8 18.1
69 56 53
94 71 84
117 123 122

3'
3:
2(

--4---

19
2:
24

1
1
(

o

2

f'

FIG. 1. Relative growth of four parts in Catostomlls latipinnis (circles) and Xyrauchen
texanus (solid dots) and corresponding measurements of the eight hybrids (crosses).
The specimens of C. latipinnis came from the upper Colorado River system in
Colorado (mostly) and northern Utah at or near the places where the hybrids
were obtained. Those of X. texanus are from all parts of the range of the species.
The measurements were made by Hubbs. The growth curves were drawn from
inspection. Measurements of four additional specimens of X. texanU8 from the
Colorado River Mesa County, Colorado (U.S.N.M., Nos. 132468 and 132469),
made after Fi~res 1 and 2 were prepared, confirm essentially the position of the
lines for that species at lengths of 320 to 398 mm., except for the length of the
longest gillraker (as noted in the text).

5.76
6.60
6.!W

68.0
81.6
81.0

7
(

4

6f
77
8

1
2
1

17.0
20.8
18.5

52
61
123

* Distance from front of upper lip to line joining posterior tips of lobes of lower
lip.
t Least distance between papillae at extreme base of lobes of lower lip, but dis-
regarding papillae at isthmus that clearly arise between the lobes.
t Values not entered, since at this length the parental species seem not to differ
in this character.