eee 5 ‘ 6we te ge . 2 wt ast BL ma ates Ay eoiet aoe a RM ( the coral used was withoot the ofl scum and had ne count above background on the survey meter. The fish in #6 has likewise fed regularly, Aquaria #1, 3 and 4 were retained as controls, Six larger aquaria, 12" x 24" x 16", were set up originally but were not as satisfactory as the setup for the smaller aquarina described above, The large aquaria are now being used as supply tanks for fish and other marine animals as well as for an irradiation mortality experiment with the marine snail, Thaislamsliosa. On April 14th six more of the smaller aquaria were delivered and were set up in the same manner as those for the fletfish, Tide Pool johnnies, a sculpin, Oligocuttus maculosus, were placed in these aquaria, They have not yet been used axperimentally but seem well adapted to their new environment. fhe experiment in aquaria #2 and #5 will be contined until it is believed that the fish is about to die, At that time tissues will be preserved for histological studies, Project VI. Observations on the amphipods were discontimed because of high mortalities among the controls. Varine snails, Thais lamellosa, A report will be submitted. that had been surviving well and X-rayed on April 2, Exposures given, and mumbers of snails e «3 1) in 15-gallon aerated aquaria, were individually marked with a number irradiated, were: 10,000 r - 23; S00 r - 6; 200 r- 9) SO r=- 93 and 200 r~- 9, 1250 r = 93 After 3 weeks the mortalities among irra- diated and control snails were approximately equal, The snails spawned in the aquaria, attaching their egg cases to rocks, shells, and especially to the glass sides of the aquaria. When only a few egg cases were deposited, thelr positions were recorded along with z we _, DO® ARCHIVES