Table 9. — Xunthcr of slimy siulpins taken per 10-minule Irawl low at various depths, Fettruari/ IS to November Jf, 196^ 



Depth 



]5ate 



Fttttioms 



3 



5 



7 



in _ _ 



12 



15 



17 



20 



2."i__ ___ _ . 



:!() _ _ . 



35 



40 



45 



.')() 



1 No data. 



jii-eat quaiititie.s of alewives). Smsill numbers a])- 

 pcared in the catches at 45 and 50 fatlionis on 

 Marcli If), ))iit distribution had not chaiifred si<i- 

 nificantly. In every later series, slimy sculpins were 

 found at all depths greater than 17 fathoms. A 

 sli<>ht shift shoreward was evident on April 15, 

 when jii'eatest numbers were at 7 to 30 fathoms. 

 They had started to move away from shallow water 

 by May 5, when relatively few weie at 12 fathoms 

 or shallower, and none were at 3 fathoms. A gen- 

 eral trend away from shore continued thereafter 

 until fall. On May 2(5 the shallowest dei)th of cap- 

 ture was 12 fathoms, and on August 21 it was 17 

 fathoms; largest numbers in the period May 26- 

 Augnst 21 were at 20 to 40 fathoms. On Octo])er 14 

 and Xovembei- 4 most were at 25 to 40 fathoms, and 

 few were at 20 fathoms or shallower. 



Slimy sculpins beyond the earlier growth stages 

 ordinai'ily are considered strict bottom dwellers, 

 but at times larger ones may ascend several fath- 

 oms above the bottom in T>ake Michigan. On May 

 20, 1055, 20 (i)i'obably slimy sculpins, but possibly 

 spoonhead sculpins) were caught at night (al)out 

 2000 e.s.t.) in a trawl fishe.l by the R/V fisro 6 

 fathoms above the bottom where total depth was 

 23 fathoms: another was taken at night on Novem- 

 ber 18, 1954, 27 fathoms al)ove the bottom at a 40- 

 fathom depth. On Jmie 20, l!)fi7, 31 slimy sculpins 

 wei'e caught dui-ing daytime by the Bureau's R/V 

 S/scoii-ef 3 to !) fatlionis abo\-e the bottom in turliid 



water 13 to 14 fathoms deep in western Lake Su- 

 perior (Merry 11 Bailey, personal communication). 



Slimy sculpins were concentrated in deeper 

 water in the Apostle Islands region of Lake Su- 

 perior than in southeastern Lake Michigan; they 

 were most common in the Apostle Islands at depths 

 greater than 40 fathoms, and probably the greatest 

 numbers were at 50 to 59 fathoms (Dryer, 1966) . 



The depth distribution of .slimy sculpins in 

 southeastern Lake Michigan varied noticealily with 

 size in winter and early spring, but not thereafter. 

 Scul])ins at intermediate depths were smaller than 

 at otiier depths in February to May. In tlie live se- 

 ries of February 13 to May 2(1, tlie average weights 

 of sculi)ins taken at depths less than 30 fathoms 

 were 0.36, 0..34, 0.32, 0.24, and 0.23 ounce (10.2, 9.6, 

 9. 1 , 6.8, and 6.5 g. ) respectively ; at 30 to 40 fathoms 

 the averages were 0.27, 0.27, 0.14, 0.12, and 0.16 

 ounce (7.7, 7.7, 4.0, 3.4, and 4.5 g.) ; and at 45 and 50 

 fathoms (no data for FelnMiary 13 and March 11) 

 the weights were 0.30, 0.21, and 0.25 ounce (S.5. 

 6.0, and 7.1 g.). Xo obvious size-depth relation 

 e.xisted after May, but some tendency existed for 

 the lai-ger fish to be in intermediate depths in Au- 

 gust-November — the opix)site of the situation in 

 early season. 



FOURHORN SCULPIN 



Fourhorn sculpins (also called deepwater scul- 

 pins) are confined to deep water much more than 



FISH DISTRIRIITIOX IX SOUTHEASTERN LAKE MICHIGAN 



11 



