Growing Freshwater Sponge Gemmules into Adulthood for Preliminary Utilization as Gray Water Filters.

Abstract

Freshwater sponges are multicellular sessile heterotrophs, extracting their nutrients from their surrounding water environment through a process called filter feeding. As the river current flows through their internal canals, they collect essential minerals and ions to grow such as magnesium, potassium, sodium, and nitrogen. During unfavorable environmental conditions, these sponges produce gemmules within their adult tissue to survive these adverse conditions. When conditions become favorable for growth, gemmules will then release totipotent archeocytes, which will differentiate into specialized cells needed for growth to produce another adult sponge. Locally collected sponge gemmules were subjected to three treatments to stimulate hatching and measure their growth in vitro. Overall, these results provide the first records of hatching conditions for Tennessee sponges. The sponge Ephydatia fluviatilis proved to be the most robust species, hatching in a wide variety of in vitro conditions. The three other species used in this study showed more mixed results. Strekal’s medium in larger petri dishes were the optimal conditions for sponge hatching and growth in these experiments. The results of sponge feeding trials were not determinant of an optimal treatment, and further research is needed in this area. The foundational knowledge generated in this study will serve as a steppingstone for future research to potentially use sponges as a living filter for gray water reduction.