Some Approaches to the Recovery of Baikal Sponge Populations: A Review

The unique ecosystem of Lake Baikal is composed of diverse and mainly endemic flora and fauna. The sponge fauna of Baikal is represented by two families, endemic Lubomirskiidae and cosmopolitan Spongillidae . In recent years, the situation with Lake Baikal has been characterized as catastrophic, especially in the littoral zone. There are numerous reports about the suppressed state of Baikal sponges and a decrease in the magnitudes of their populations in many lake areas. Scientists insist that not only nature-conservative, but also nature-restoring measures are required. This review discusses the basic known sponge cultivation techniques and approaches. Four main approaches to the ex situ and in situ sponge cultivation in the global practice are described in the most detail: (1) cultivation from larvae, (2) cultivation from primmorphs (sponge cell cultures), (3) cultivation from resting stages (gemmules and reduction bodies), and (4) cultivation from explants (fragments of living tissues detached from a parent organism). Attempts to use the described common approaches for the cultivation of Baikal sponges are also discussed. Based on the analysis of existing publications, we assume that the use of the most effective of the abovementioned approaches will make it possible to develop a technology for cultivating Baikal sponges.