12 MORTALITY OF FISHES, WEST COAST OF FLORIDA. 



ii|)i);r.eiitly Avholesome food. The liver was slightly abnormal in 

 appearance, being faintly mottled with a lighter shade of brown. 

 The mucous covering of the body was transparent and colorless; 

 none of the organs were distended by gas, nor were gas bubbles 

 observed in the blood vessels. The eyes were clear, and no evidence 

 of fungus was seen. The coloring of the fish was vigorous. 



Fishes in a moribund condition were i-eported as having been ob- 

 served in the passes, in the Gulf, and in Tarpon Bay, but since the 

 carcasses drifted with wind and tide the mere presence of dead fish 

 was not an indication of a mortality at any giA'en place. The condi- 

 tion sought for must have been immediately at hand, however, when 

 a moribund fi^h was observed on November 19. 



It was tv small filefish {M onacanthus sp.), and was first observed 

 near the dock at Bailey's Wharf, Sanibel, in water not over 3 feet 

 deep. The fish was brilliantly mottled with maroon on a slate- 

 colored background. It was drifting upon its side, making but 

 slight effort to balance. This fish was captured and placed in a 

 bucket of the water from which the fish was taken. A moment later 

 a small, active, pinfish was captured in the same place and likewise 

 kept in another bucket with some of the same water. The color of 

 the filefish faded, but repeatedly revived when the fish was disturbed ; 

 each response, however, was weaker than the preceding one until the 

 fish died, and the color faded in about 2 hours. The pinfish, taken at 

 the same time and place, lived till it was released at Fort Myers, 

 about 6 hours later. Both species had repeatedly been noted dead 

 upon the beach. Within 50 feet of the point where the filefish was 

 dying numerous mangrove-snappers and sheepshead were seen, quite 

 healthy in appearance. So we have the anomalous condition of 

 dying fish and perfectly healthy fish within 50 feet of each other 

 and in the same water, with certain knowledge that all the species 

 concerned are subject to destruction by the abnormality responsible 

 for the death of so many species. 



Kepresentations were made to the writer concerning the pollution 

 of Peace River. This is a small sluggish stream, tributary to Char- 

 lotte Harbor, and drains a region now being worked for phosphate 

 rock. It was said that the waste from the works destroyed the fish. 

 However true this may be, a brief visit only was necessary to show 

 that such a pollution could have no bearing on the mortality under 

 consideration. Small fish as well as vegetation were in the stream ; 

 and, besides, the stream is of insignificant size. 



DISCUSSION OF POSSIBLE CAUSES OF THIS AND SIMILAR DIS- 

 ASTERS IN OTHER PARTS OF THE WORLD. 



It may said at the beginning of this discussion that while a definite 

 conclusion has not been reached as to the cause or causes of this 



