Postlarval Segments

Postlarval body segments (postlarval segments, PLS) are segments in the body structure of ectodes, mesodermal and endodermal origin. Metameric animals are invertebrates (mainly annelids, some planarians, starfish), on the head of which there are bilateral structures with complex eyes, organs of touch, smell, etc. The postlarval segment can be formed during embryogenesis earlier or later than the provisional segments, for example, in Nautilus, the postlarval segment develops into a spiral; in hagfishes and ascidians

Many living organisms have bilateral symmetry. Accordingly, most of their body is symmetrical. And one can often observe similar variants of symmetry in the complex anatomy of the body. An organism with a high rate of development is evolutionarily most successful. The similarity of an organism with its blastomeres lies in the types of cells, similar structure and cellular interactions. There are proteins that control the course of cell development (for example, the family of proteins encoded by the Wingless protein gene), as well as proteins responsible for the structural features of the cytoskeleton (EC). For comparison, we compare the signs of organism development. Everything from temperature to ionic concentration affects the development of an organism, which can be useful to us as an explanatory force for determining the individual characteristics of a particular organism. There is also the ability to trace signals to cytoplasmic parameters, which allows us to chart a course for cellular development more accurately. Physiological processes responsible for the development of organisms are factors that impede the free flow of metabolic processes within the organism, although the metabolism of the organism has some influence on the physical form of the organism in question.