Rotifera sentence example
This appears to indicate B that the Polyzoa are remotely allied to other phyla in which this type of larva prevails, and in particular to the Mollusca and Chaetopoda, as well as to the Rotifera, which are regarded as persistent Trochospheres.
The Rotifera are all aquatic, the majority dwelling in fresh water with Protozoa and Protophyta, as well as Entomostracous Crustacea.
Most remarkable is its resemblance to the adult form of the Wheel animalcules, or Rotifera, which retain the prae-oral ciliated band as their chief organ of locomotion and prehension throughout life.
As in the Rotifera, it serves the veliger larva as an organ of locomotion.
In some species of Dinophilus there is pronounced sexual dimorphism (the male being small and without gut) as in the Rotifera.Advertisement
The resemblance of Dinophilus to the Rotifera is, however, quite superficial, and the general structure of this genus with distinct traces of segmentation, especially in the embryo, points to its close affinity, if not to Polygordius in particular, at all events to the Annelida.
The animals thus associated, the Rotifera, Chaetopoda and Arthropoda, are composed of a larger or smaller number of hollow rings, each ring possessing typically a pair of hollow lateral appendages, moved by intrinsic muscles and penetrated by blood-spaces.
The Rotifera are characterized by the retention of what appears in Molluscs and Chaetopods as an embryonic organ, the velum or ciliated prae-oral girdle, as a locomotor and foodseizing apparatus, and by the reduction of the muscular parapodia to a rudimentary or non-existent condition in all present surviving forms except Pedalion.
The thick-skinned round worms, such as the common horse-worm and the threadworms (see Nematoda), together with the Nematomorpha, Chaetosomatida, Desmoscolecida and Acanthocephala, form a fairly natural group. The Rotifera, with probably the Kinorhyncha and Gastrotricha, are again isolated.
De Blainville included in his group many unicellular forms such as Noctiluca (see PROTOZOA), sea-anemones, corals, jelly-fish and hydroid polyps, echinoderms, polyzoa and rotifera.Advertisement