9492

• UCREFRP Catalog Number: 9492
• Author: Snyder, D. E.
• Title: Computer-Interactive Key to Sucker Larvae and Early Juveniles of the Upper Colorado River Basin with Description of Longnose Sucker.
• USFW Year: 2003.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

Table 5. Continued

2. Pigment over ventral to ventro-lateral surfaces of gill covers (opercula)
1. absent.
2. present but not consisting of or including a distinct oblique row of 3 or more melanophores near or along margin of either preopercle.
3. consisting of or including a distinct oblique row of 3 or more melanophores near or along margin of one or both preopercles.
3. Pigment on ventral surface of heart region
1. absent.
2. present.
4. Pigment under chin (anterior ventral surface of lower jaw)
1. absent.
2. present.
5. Dorsal body pigmentation between head and last myomere (for specimens with> 12 melanophores on dorsal surface)
I. not scattered or scattered with at least a partial distinct line of melanophores on or lateral (and parallel) to dorsal midline.
2. scattered with no distinct lines ofmelanophores on or lateral (and parallel) to dorsal midline.
6. Dorsal body pigmentation between head and last myomere
1. scattered more or less evenly (with or without emphasis on distinct lines ofmelanophores on or lateral and parallel to dorsal midline).
2. scattered but in a blotchy pattern (with or without emphasis on distinct lines ofmelanophores on or lateral and parallel to dorsal midline).
7. Dorsal midline from shortly behind head to near last myomeres
1. with s24 melanophores in a short, discontinuous, or well-spaced line, or (rarely) with no distinct line ofmelanophores.
2. with ,,25 melanophores but in a short or distinctly discontinuous line.
3. with ,,25 melanophores in a distinct continuous or nearly continuous, full-length line.
8. Dorsal surface lateral to midline from shortly behind head to about 2/3 distance to last myomeres
I. without distinct lines of melanophores along either side of dorsal midline.
2. with distinctly short or discontinuous lines of melanophores along one or both sides of dorsal midline.
3. with distinct continuous or nearly continuous, full-length lines ofmelanophores along (parallel to) each side of dorsal midline.
9. Melanophores in lines lateral (and parallel) to dorsal midline between head and 2/3 distance to last myorneres mostly
1. in single file.
2. in obliquely oriented pairs or groups resulting in a herringbone pattern.
10. Dorsal surface of head pigmented
1. only over hindbrain (posterior to middle of eyes).
2. over both mid- and hindbrain (anterior and posterior to middle of eyes).
11. Lateral surface of body above horizontal myosepta (or lateral midline), exclusive of melanophores associated with horizontal myosepta, air
bladder, visceral cavity (peritoneum), or gut,
1. unpigmented.
2. with 1-5 melanophores.
3. with ,,6 melanophores.
12. Lateral surface of body below horizontal myosepta (or lateral midline), exclusive of melanophores associated with horizontal myosepta, air
bladder, visceral cavity (peritoneum), or gut,
1. unpigmented.
2. with 1-5 melanophores.
3. with ,,6 melanophores.
13. Lateral surface of head posterior to eyes
1. unpigmented.
2. with 1-5 melanophores.
3. pigmented with ,,6 rnelanophores.
14. Pigmentation on lateral surfaces of body above bottom-of-eye level and anterior to vent, exclusive ofmelanophores associated with horizontal
myosepta, air bladder, visceral cavity (peritoneum), or gut,
I. scattered only partially down to the horizontal myoseptum (lateral midline).
2. scattered fully and evenly down to the horizontal myoseptum with few if any melanophores below the myoseptum.
3. scattered evenly or in blotchy pattern (continuous with dorsal and dorso-Iateral surface pattern) down to horizontal myoseptum and at
least partially to bottom-of-eye level below. /
15. Pigmentation on lateral to ventra-lateral surfaces of body below bottom-of-eye level, exclusive of melanophores associated with horizontal
myosepta, air bladder, visceral cavity (peritoneum), or gut,
I. absent including caudal peduncle.
2. absent except on caudal peduncle.
3. present.
16. Mid-lateral surface of body
1. with no distinct, near-eye-size spots of pigment.
2. with I distinct, near-eye-size spot of pigment on caudal peduncle near base of caudal fin.
3. with 2 distinct, near-eye-size spots of pigment, one between head and dorsal fin and the other between pelvic and anal fins.
4. with 3 distinct, near-eye-size spots of pigment, one between head and dorsal fin, the second between pelvic and anal fins, and the third on
the caudal peduncle near the base of the tail.
17. Pigment outlining scales
I. absent or light.
2. bold.

31