Vol 55, No 1 (2024)

The germ layers theory is a fundamental synthesis of comparative and evolutionary embryology, which is essential for proving the unity of the multicellular animals. In this article, we substantiate the point of view that among Metazoa, in addition to Diploblastica and Triploblastica, there is a third group, which lacks germ layers, and on this basis we propose to call it Ablastica.

The blue king crab Paralithodes platypus (Brandt, 1851) is a widespread and abundant member of the family Lithodidae in the Pacific Ocean. However, its population size in the Sea of Japan is subject to strong fluctuations. Due to the low abundance of blue crab, its commercial fishery in the Sea of Japan has been prohibited since 2022. Therefore, the aim of the study was to evaluate the growth characteristics and growth potential of the blue king crab in the Sea of Japan relative to other aggregations of this species in the Sea of Okhotsk and the Bering Sea. The growth was studied according to the literature and our own data, which were collected on counting-trap surveys in the coastal regions of the Sea of Japan in 2011–2014. According to the Bertalanffy equation, male blue king crab in the Sea of Japan reach the carapace width CWinf = 193.5 mm, females – 162.1 mm. Comparison results of growth rate of the aggregation in the Sea of Japan showed significant differences with crabs off the Shantar Islands and eastern Sakhalin and did not note statistically significant differences in growth relative to aggregations in Shelikhov Bay and in the Bering Sea. Probably, first of all, such differences are the result of the complex influence of hydrological habitat conditions, food productivity of water areas, as well as competition, both interspecific and intraspecific.

Evolutionary and developmental biology are among the most dynamically developing areas of modern biology. Both have a long and turbulent history, especially in Russia (USSR). However, any science develops thanks to the breakthrough research of individual scientists and scientific teams. In this paper, we briefly analyzed the main theoretical works of Leningrad State University professor G. P. Korotkova (1924–2009), who made a significant contribution to general biology at the end of the twentieth century. G. P. Korotkova is known for her pioneering work in the field of regeneration of invertebrate animals and, first of all, sponges, evolutionary and philosophical aspects of biology. In particular, her contribution to the theoretical aspects of regenerative biology, to the development of philosophical aspects of the problems of wholenessis considered. The principles of her original hypothesis of the origin and phase evolution of ontogenesis are briefly outlined, as well as her ideas regarding the theoretical aspects of the biology and organization of sponges (Porifera).