NATURAL HISTORY OF THE SEA LAMPREY, PETROMYZON MARINUS, IN MICHIGAN.

-319 -

APFEYD IX G
Table 7. Depths, dimensions, and materials used in the construction of sea lamprey nests in the Little Ocqueoc
River (Station 5B). (All depths and dimensions in inches. Bottom type symbols: "P" - pea gravel. 3/16" to
3/8" in diameter; "'" - marble gravel, 1/2" to 1" in diameter; "E" - egg gravel, 1 and 1/4" to 2 and 1/2" in diameter; "R" - rubble; nS" - sand. All bottom types listed in order of dominance.)
Depth to Downstream rim of nest Upstream rim of nest
center Dimensions Depth to Depth to Bottom t7ype- Remarks on
of nest of nest summnit Materials samnit Materials floor of nest location of nest
7.5 20.0 2.0 M, E 4.0 o, E, R P, R Forward slope of bar
6.0 16.0 0.8 9, E 1.0 M, E, R P " " " "
7.5 10.0o.0 E, R 4.0 E, E P Intermediate between bars
8.5 17.0 4.0 U, E 7.0 U, E P Midstream
9.0 10.0 5.0 B,! 6.0 U P, R "
10.5 17.5 11.5 R, P, E 8.0 M, E, P, R "
10.0 17.0 x 23.0 5.5 P, E S.O P, S, R P, Tinder roof of logs and cedar
9.0 16.0 4.5 U, large rock 4,5 i, E P Midstream bOWs
6.0 18.0 x 20.0 2.0 m, E / U, E P Close to bank
11.0 19.0 x 20.0 3.5 UM E 9.0 S, P, M P, S Midstream
6.0 I4.0 3.0 P, M, E 4.0 M, R P, S Forward slope of bar
7.5 13.0 x 14.0 2.5 P, M, E 3.0 M, E P, S a n n"
8.5 23.0 2.0 PF U, E / E, B P, R Midstream
8.5 13.0 x 21.0 2.0 M, E P, R P
10.0 22.0 3.0 M, E 6.0 P. E, R P, R R
10.5 14.0 5.5 E, large rock 8.0 P, R P, E Forward slope of bar
10.0 24.0 2.5, E 4/ U. P, " " " "
7.0 13.0 2.0 M, E-, E P, S Under snags near bank
7.0 17.0 2.0 P, U, E 3.5 P, M P Midstream
7.5 23.0 1.5 P, M, E 4.5 P. M P "
9.5 21.0 3.5 U, E / U, E P, B Forward slope of bar
8.5 12.0 6.0 P, M, R 7-0 1, R P, M, E ~" B n
10.0 22.0 x 24.0 2.5 P, M, E M, E P, M " n " n
9.0 22.0 4.5 E, B, 5.5 R P, R Midstream
7.0 o 1.0 3.5 E., 4.5 E P, E R
9.0 16.0 4.0 P, M 7.0 P, R P, S Close to bank
15.o0 20.0 3.5, E 11.0 E, R P Midstream
9.0 14.0 2.0 M, E 4/ E, R P Close to bank
11.0 14.0 7.5 P, M 4/ P. M P Midstream
12.5 25.0 6.0 E. u, S 10.0 M, B P *
13.5 19.0 7.0 Large roc* 9.0 P, U, B P, B ~
Average 9.0 17.71/ 3.6... 6.1
4 Upstream rim of nest poorly defined or not elaborated during nest constraction. Materials listed are
bo tom type immediately vpstream from nest proper.
Mean diameter of asymetrical nests included in average.