The Relation of the Substratum to the Metamorphosis of Ophelia Larvae

Publisher Website
Google Scholar
Abstract
Expts. with larvae of O. bicornis showed that they metamorphose most readily in sand from their natural habitat and with hesitancy or not at all in sands from other sources. Their natural sand consists largely of smooth rounded grains of quartz, very uniform in size; sands of smaller and more angular grains are unfavorable to settlement and metamorphosis. It appears that size and shape of the sand grains, or perhaps, more likely, the sizes and shapes of the interestices among the grains, perceived probably by the tactile sense, is the main stimulus to metamorphosis. Chemical substances dissolving out of the sands do not seem to be responsible for this. There is a period of time, amounting under favorable conditions to several weeks, during which an Ophelia larva is able to settle and metamorphose as soon as it comes into contact with a substratum suitable for adult life. The ability of the larvae to distinguish bottom deposits suitable for adult life from those which are unsuitable must be of great advantage to the sp. in maintaining normal distr. and in conserving larvae. Larvae kept indefinitely in glass dishes without sand, or with a deposit of the wrong kind, eventually either die when metamorphosing or attempt to metamorphose with greater or less success.

This publication has 6 references indexed in Scilit: