The effectiveness of gill nets in trapping turtles is indicated by information kindly supplied by Mr. Alfred Houser on gill-net operations from July through December, 1952, under the direction of Mr. "Bud" Oldham, a commercial fisherman. The 4-inch mesh nets were in Lake Texoma at the mouth of Briar Creek, two miles south of Powell, Marshall County, Oklahoma, in 25 to 30 feet of water. Eighty to 90 per cent of the turtles secured were softshells; more were taken near shoreline than away from shore even though the depth was about the same. An average of only one turtle every four days was taken in July and August when the turtles presumably are most active (Table 1). One gill-net day is equivalent to one gill net, 200 yards long, operated for 24 hours. TABLE 1. The Abundance of Turtles as Revealed by Gill-net Operations in Lake Texoma, 1952. ===========+==========+===========+=============== | Gill-net | Number of | Gill-net days MONTH | days | turtles | per turtle -----------+----------+-----------+--------------- July | 835 | 213 | 3.9 August | 816 | 199 | 4.6 September | 743 | 42 | 17.7 October | 1661 | 82 | 20.3 November | 1322 | 48 | 27.5 December | 864 | 5 | 172.8 -----------+----------+-----------+--------------- Dr. Virgil Dowell, while making fishery studies two miles east of Willis, Marshall County, Oklahoma, caught, on the average, 1.5 turtles per day. Of 75 turtles collected from July 1 through October 18, 1953, 66 were _Trionyx_ (_spinifer_ and _muticus_), five were _Graptemys_ and four were _Pseudemys scripta_. No more than two gill nets were used simultaneously. The nets were moved from time to time and varied in dimensions, but those used most of the time were 200 feet long and eight feet deep with a 3-inch mesh. The few captures by Houser probably resulted from long-continued trapping in one place; the gill nets were not moved in the entire six-month period or for some time previously. Breckenridge (1955:6) commented on the sedentary nature of _spinifer_ (in Minnesota) and quoted a professional turtle trapper as stating that "after a section of a river has been trapped heavily for softshells, little success can be expected in that area for as much as three or four years thereafter." Both Houser's and Dowell's data indicate a higher percentage of soft-shelled turtles collected than any other species. The number caught probably depends, at least partly, on the food habits of the species and is influenced by the enmeshed fish, which, serving as a food source, attract the turtles. Materials and Procedures