How to use Trochosphere in a sentence
It has simply been traced as far as the formation of a diblastula which acquires a ciliated band, and becomes a nearly spherical trochosphere.
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.
B, The diblastula has become a trochosphere by the development of the ciliated ring y r (optical section).
C, Side view of the trochosphere with commencing formation of the foot.
D, Further advanced trochosphere (optical section).Advertisement
E, The trochosphere passing to the veliger stage, dorsal view showing the formation of the primitive shell-sac.
In development they pass through the typical trochosphere and veliger stages provided with boat-like shell.
When the middle and hinder regions of the blastopore are closing in, an equatorial ridge of ciliated cells is formed, converting the embryo into a typical trochosphere.
The foot now protrudes below the mouth, and the post-oral hemisphere of the trochosphere grows more rapidly then the anterior or velar area.
The larva swims by a ri ig of cilia, which corresponds with the praeoral circlet of a Trochosphere.Advertisement
The early larva of Anodonta is not unlike the trochosphere of other Lamellibranchs, but the mouth is wanting.
D, E, F, Trochosphere stage, D fp, Pore in the foot (belonging mf, The mantle-flap or limbus to the pedal gland?).
B, The Gastrula has become a Trochosphere by the development of the ciliated ring vr (optical section).
C, Side view of the Trochosphere with commencing formation of the foot.
D, Further advanced Trochosphere (optical section).Advertisement
E, The Trochosphere passing to the Veliger stage, dorsal view showing the formation of the primitive shell-sac.
The larval form thus produced is known as the trochosphere.
By the development of a ciliated ring just in front of the mouth the embryo becomes a trochosphere.
The external surface of the trochosphere is formed of a number of ciliated test-cells.
This little creature, which has many of the features of a Trochosphere larva, swims about at the surface of the sea for about a month and grows rapidly.Advertisement
Most observers consider that Actinotrocha is a highly modified Trochosphere, and this would give it some claim to be regarded as distantly related to the Entoproct Polyzoa and to other groups which have a Trochosphere larva.
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.
B, Trochosphere of an Opisthobranch (Pleurobranchidium) showing - shgr, the shell-gland or primitive shell-sac; v, the cilia of the velum; ph, the commencing stomodaeum or oral invagination; ot, the left otocyst; pg, red-coloured pigment spot.