Notes on the Occurrence of Amphioxus at Singapore

Abstract

THE following notes on the occurrence of Branchiostoma belcheri, Gray, at Singapore have been written at the suggestion of Dr. Arthur Willey, who has kindly examined and identified the specimens for me; they were collected by Mr. W. F. Lanchester and myself, and are, I believe, the first that have been obtained from the locality. The first indication we had of the presence of Amphioxus in the district occurred about the middle of November 1898, when a number of young examples were found amongst the material collected by tow-netting at the extreme surface of the water about one or two hours after sunset. At the time we were living on a small island about ten miles off Singapore, and we tow-netted every night just outside or over the edge of the reef surrounding the island. The tidal currents were generally very strong, and no doubt brought a considerable amount of the plankton from the deeper layers to the surface. Up till the end of November (when we left the island) young Amphioxus continued to be fairly plentiful; but they were never met with elsewhere, and in June last year I visited the island again and could find no trace of them.