. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LUMINESCENCE OF A NEMERTEAN 167 15 km. off the Station. But the nemerteans are not abundant. Only six or seven individuals at best, or sometimes only one or two indi- viduals, are obtained on about two hundred Chelyosoma, which are collected by the fishermen as the result of one day's work. The nemerteans are reddish orange in color. They have many eyes. They vary in length, from 53-115 cm., and are about mm. in diameter, when they are stretched. I found one individual 10 cm. long, but one so short is extremely rare.
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LUMINESCENCE OF A NEMERTEAN 167 15 km. off the Station. But the nemerteans are not abundant. Only six or seven individuals at best, or sometimes only one or two indi- viduals, are obtained on about two hundred Chelyosoma, which are collected by the fishermen as the result of one day's work. The nemerteans are reddish orange in color. They have many eyes. They vary in length, from 53-115 cm., and are about mm. in diameter, when they are stretched. I found one individual 10 cm. long, but one so short is extremely rare. The female animal is readily distinguished during the summer season because it is full of eggs or enlarged gonads, but I could not distinguish the males. The animals coil up on the wall of a large vat of running sea water or on the bottom, attached by the slime which is abundantly secreted from the surface of its body (Fig. 1). They remain there quietly for two months or more, if they are not FIG. 1. The living and coiled whole Emplectonema kandai about 115 cm. long. About natural size. (Photographed by N. Abe at my request.) The animals flash brilliantly only on stimulation. The stimulus may be mechanical, chemical, thermal or electrical. The light may appear on all parts of the body, but it disappears in one or two seconds. It is whitish green in color. Mechanical Stimuli The animal flashes when a glass rod or a finger is gently touched to the surface or surfaces of the coiled body. The light does not spread very far from the place or places of the contact, and lasts for only one or two seconds. Its intensity varies, depending on the strength of the contact. I thought at first that some luminous material was thrown into the sea water mixed in a slime discharged from the surface of the animal body, but this observation turned out to be incorrect. If the coiled animal is strongly rubbed between the fingers, a brilliant light appears, but it is not observed that any
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
