Free-swimming Sentence Examples

A, A hydriform person giving rise to medusiform person by budding from th margin of the disk; B, free swimming medusa (Steenstrupia of Forbes) detached from the same, with manubrial genitali.

If the embryo is set free as a free-swimming, so-called planula-larva, in the blastula, parenchymula, or gastrula stage, then a free actinula stage is not found; if, on the other hand, a free actinula occurs, then there is no free planula stage.

Brooks, on the other hand, as stated above, regards the medusa as the older type and looks upon both polyp and medusa, in the Hydromedusae, as derived from a free-swimming or floating actinula, the polyp being thus merely a fixed nutritive stage, possessing secondarily acquired powers of multiplication by budding.

The parasite effects a lodgment in the host either by invading it as a free-swimming planula, or, apparently, in other cases, as a spore-embryo which is captured and swallowed as food by the host.

It is absurd to call the larva of a newt or of a Caecilian a tadpole, nor is the free-swimming embryo of a frog as it leaves the egg a tadpole.

Free-swimming organisms without cell-membranes exist in both, and from them series of forms can be traced in both directions.

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.

About this stage the larvae leave the broodpouch, which is a lateral or median cavity in the body of the female, and lead a free swimming life in the ocean.

He upset (1830) Cuvier's retention of the Cirripedes among Mollusca, and his subsequent treatment of them as an isolated class, by showing that they begin life as free-swimming Crustacea identical with the young forms of other Crustacea.

A, The free-swimming embryo.- B, A sporocyst containing young rediae.

The Polyzoa are colonial animals, the colony (zoarium) originating in most cases from a free-swimming larva, which attaches itself to some solid object and becomes metamorphosed into the primary individual, or "ancestrula."

It is sufficient to state here that the medusa is usually a free-swimming animal, floating mouth downwards on the open seas, but in some cases it may be attached by its aboral pole, like a polyp, to some firm basis, either temporarily or permanently.

Great apparent differences may also be brought about by variations in the period at which the embryo is set free as a larva, and since two free-swimming stages, planula and actinula, are unnecessary, one or other of them is always suppressed.

Among them is the cosmopolitan Calanus finmarchicus, the earliest described (by Bishop Gunner in 1770) of all the marine free-swimming Copepoda.

It is in this position that free-swimming forms glide over the substratum of organic debris in which they find their food.

Melicertaceae; females tubicolous, usually attached, or forming spherical floating social aggregates; males free swimming.

In Yoldia and Nucula proxima the ova are set free in the water and the test-larvae are free-swimming, but in Nucula delphinodonta the female forms a thin-walled egg-case of mucus attached to the posterior end of the shell and in communication with the pallial chamber; in this case the eggs develop and the test-larva is enclosed.

Some, like many Cephalopods and the Pteropods, are pelagic or free-swimming; others creep or lie on the sea bottom.

It is a top-shaped, free-swimming organism provided with a preoral band of cilia,.

As already stated, a medusa of this order may be free-swimming or sessile in habit.

Thus in Pelagia the scyphistoma-stage is free-swimming and changes directly into the ephyra, which in its turn grows into the adult form.

The majority of the Crustacea are hatched from the egg in a form differing more or less from that of the adult, and pass through a series of free-swimming larval stages.

Cleavage leads to the formation of an epibolic gastrula and ciliated embryo which hatches as a free-swimming larva remarkably like that of a Polychaete worm (D).

The larvae of corals are free swimming ciliated forms known as planulae, and they do not acquire a corallum until they fix themselves.

The more complex umbrellashaped colonies of colonies (synrhabdosomes) described as provided with a common swimming bladder (pneumatophore?) may have attained a holo-planktonic or free-swimming mode of existence.

The larvae are free-swimming and have the pelvic fins elongated into filaments.

There is no reason to suppose that the central apical plate of certain free-swimming crinoids has any more to do with the distal foot-plate of the larval Antedon stem than has the so-called centrodorsal of Antedon itself, which is nothing but the compressed proximal end of the stem.

It was not till Vaughan Thompson demonstrated, in 1830, their development from a free-swimming and typically Crustacean larva that it came to be recognized that, in Huxley's graphic phrase, "a barnacle may be said to be a Crustacean fixed by its head and kicking the food into its mouth with its legs."

The embryos are free-swimming, active forms, but in adult life the animals are fixed head downwards, and are very degenerate.

With the exception of a number of forms in which the whole development takes place within the egg or in the body of the mother, batrachians undergo metamorphoses, the young passing through a free-swimming, gill-breathing period of considerable duration, during which their appearance, structure, and often their regime, are essentially different from those of the mature form.

For example the free swimming cercaria and miracidia use highly specialized sensory organelles to locate their hosts.

Large potato cod often hang out to the north and free swimming morays are common.

In recent years there has been quite a craze for the Polish or Check heavily weighted nymphs that imitate free-swimming caddis larvae.

I also did a couple of night dives, where I saw free-swimming morays, octopus, turtles, couple of rays.

Blue spotted rays seemed to abound on the sand here and our first sight of a free swimming moray eel.

Try the EPIC too - they have lost of stuff including free swimming sessions tel.

There is no free-swimming planula larva, but the stage corresponding to it is passed over in an enveloping cyst, which is secreted round the embryo by its own ectodermal layer, shortly after the germ-layer formation is complete, i.e.

As they are weaned onto food suitable to small salmon, the fry become free swimming rather than bottom feeders.