decided preference for the slow-flowing, soft- 

 bottomed pools of Divisions 7 and 8. 



Sand Shiner. --The sand shiner showed a sharp 

 change in abundance between the wooded and open 

 areas, with 99 per cent of the individuals coming 

 from the upper, sunny area. Notropis volucellus, 

 which closely resembles the sand shiner, was 

 present in the Salt Fork River but was not collected 

 in Jordan Creek. 



Suckermouth Minnow. —Minnows of this species 

 were most abundant in divisions of the wooded 

 area and were associated with a steeper gradient 

 and harder bottom than are found farther upstream. 

 They were usually collected in riffles of moderate 

 current and depth. 



Silverjaw Minnow. — The weights and numbers 

 of minnows of this species increased in an 

 upstream direction. There was a distinct rise in 

 abundance from the wooded area to the open area; 

 86 per cent of the specimens were collected in the 

 open area. Moore, Pollock, & Lima (1950) pointed 

 out that this minnow is morphologically adapted to 

 tolerate intense light over a bright sandy bottom. 



Fathead Minnow. --One specimen of the fat- 

 head was collected in Division 3 following high 

 water stages during the fall. Forbes & Richardson 

 (1920) reported that in Illinois this species is 

 practically limited to the Mississippi River drain- 

 age, as they collected it from only four localities 

 in the headwaters of the Embarrass River of the 

 Ohio River drainage. Gerking (1945) had few 

 records for it in western Indiana. 



Bluntnose Minnow. -- This, the second most 



numerous minnow in the study section, appeared in 

 every collection. The greatest numbers were taken 

 in quiet waters over soft bottoms in the open area. 

 Its abundance was inversely proportional to the 

 steepness of the stream gradient. 



Stoneroller. -- In number the stoneroller was 

 the most abundant fish in the study section; in 

 total weight it was exceeded by only the hog 

 sucker. Minnows of this species, present in every 

 collection, seemed to prefer narrow, shallow pools 

 with gravel bottoms and rapid currents. 



Catfish Family 



The four species belonging to this family 

 comprised a relatively small part of the total fish 

 population of the Jordan Creek study section, 

 table 9. These species, table 4, can be separated 

 into two groups, based on habitat preferences: (1) 

 the bullheads, which seek mud banks along larger 

 pools, and (2) the stonecat and madtom, which in- 

 habit rocky areas of moderate to swift currents. 

 Because of differences in habitat preferences of 

 the species represented and because of great 

 differences in average size of individuals of these 

 species, there was comparatively litUe correlation 

 between the numbers and the weights of catfish 

 taken in the eight divisions, table 8. The yellow 

 buUhead made up 86 per cent of the total weight of 

 representatives of the family. 



Block Bullhead. " Four specimens of this 

 species were collected. They were taken in three 

 collections, each of which included yellow bullheads. 



Table 4. -- Number and weight (in pounds) of each of the species of catfishes collected, 1950, in 

 each of the eight divisions of Jordan Creek, and the total number and total weight of each species 

 collected in all divisions combined. 



11 



