Scientists learned how the most “stubborn” invertebrate learns to care for its offspringScience and technology01:28 | 07 November 2023

A group of international scientists led by St. Petersburg State University professor Andrei Ostrovsky and London Natural History Museum researcher Andrei Weschenbach has discovered that bryozoans, one of the surviving invertebrates on the planet, have repeatedly evolved new reproductive strategies. Adapted to filtering food, these marine organisms have evolved to care for their young. The research, supported by the Russian Science Foundation, was published in the scientific journal Proceedings of the Royal Society B.

Bryozoans or Bryozoa are aquatic invertebrates that appeared in the oceans more than 500 million years ago. They have been successful in adapting to a variety of environments, including different depths, salinity levels, and even freshwater. Bryozoans remain a diverse and important group of marine organisms. An important aspect of their survival was the emergence of care for offspring, including the development of “incubators” for embryos.

Although many modern animals practice egg-laying, evolution has continually led to the development of different methods for caring for offspring. The study found that bryozoans evolved different reproductive strategies at least a dozen times. These strategies range from transporting embryos within the body to incubating them in special chambers, often with placental nutrition. These differences demonstrate the effectiveness of evolutionary adaptations that enable bryozoans to survive in different environments.

The research of Andrei Ostrovsky and his colleagues made it possible to better understand the evolution of bryozoans and the diversity of their reproductive strategies. Scientists hope to further investigate the evolution of brood chambers and placentas, as well as the role of bryozoan larvae in the transmission of symbiotic bacteria.