noun
definition
The planktonic larva of many kinds of marine and freshwater gastropod molluscs, as well as most bivalve molluscs.
Examples of veliger in a Sentence
A well-marked trochosphere is formed by the development of an equatorial ciliated band; and subsequently, by the disproportionate growth of the lower hemisphere, the trochosphere becomes a veliger.
E, The trochosphere passing to the veliger stage, dorsal view showing the formation of the primitive shell-sac.
From the fact that Aplysia commences its life as a free-swimming veliger with a nautiloid shell not enclosed in any way by the border of the mantle, it is clear that the enclosure of the shell in the adult is a secondary process.
There is a veliger stage in development, but the velum is reduced.
Except in Oncidium, there is no longer a veliger stage in development.
A single otolith is present as in the veliger embryos of Opisthobranchia.
No ciliated An extraordinary modification of the veliger occurs in the development of Nucula and Yoldia and probably other members of the same families.
H, I, Veliger stage later than 1, The sub-pallial space, here destined to become the lung.
E, The Trochosphere passing to the Veliger stage, dorsal view showing the formation of the primitive shell-sac.
It now passes to the veliger phase, a definitely molluscan form, in which the disproportion between the area in front of the ciliated circlet and that behind it is very greatly increased, so that the former is now simply an emarginated region of the head fringed with cilia.
As in the Rotifera, it serves the veliger larva as an organ of locomotion.
The body of the veliger is characterized by the development of the visceral hump on one surface, and by that of the foot on the other.
The veliger, as soon as its shell has attained some extent and begins to assume definite shape, is no longer of a form common to Mollusca generally, but acquires characters peculiar to the partiY cular class to which its parents belong.
But in these epibolic forms, just as in the embolic Paludina, the embryo proceeds to develop its ciliated band and shellgland, passing through the earlier condition of a trochosphere to that of the veliger.
In development they pass through the typical trochosphere and veliger stages provided with boat-like shell.