Marine sponge

The filter feeding mechanism of marine sponges exposes them to water-borne toxins and bacteria, forcing them to evolve immune systems effective in fighting these pathogens. Therefore, antibacterial properties of the sponge’s defense system are effective tools that can be used in medicinal therapies. By modeling sponges’ response to pathogens, advances can be made in human medicine. This study analyzed how the pumping efficiency of the species Aplysina archeri and Aplysina lacunosa affected the antibacterial properties of the sponge. Sponges were sampled from depth ranges of 10 – 12 m, and 16 – 18 m. The pumping efficiency of each sponge was tested using water sampling (In-Ex), determined by comparing the turbidity of water before it entered and as it exited the sponge. Variation in antibacterial properties was analyzed by assembling antibiotic assays from sponge extracts. Using this method, sponges showed no bacterial inhibition. Both A. archeri and A. lacunosa filtered water more efficiently in shallow water, but this trend was not significant. This study sought to introduce information that could be useful when determining what sponge to use in pharmaceutical testing. With such knowledge, pharmaceutical companies can continue to compile qualities to formulate an ideal sponge species they should research for medicinal cures

This student research was retrieved from Physis: Journal of Marine Science XVII (Spring 2015)19: 10-16 from CIEE Bonaire.

Abstract

Some excavating sponges of the genus Cliona compete with live reef corals, often kill- ing and bioeroding entire colonies. Important aspects affecting distribution of these species, such as dispersal capability and population structure, remain largely unknown. Thus, the aim of this study was to determine levels of genetic connectivity and dispersal of Cliona delitrix across the Greater Caribbean (Caribbean Sea, Bahamas and Florida), to understand current patterns and possible future trends in their distri- bution and effects on coral reefs. Using ten species-specific microsatellite markers, we found high levels of genetic differentiation between six genetically distinct popula- tions: one in the Atlantic (Florida-Bahamas), one specific to Florida and four in the South Caribbean Sea. In Florida, two independent breeding populations are likely separated by depth. Gene flow and ecological dispersal occur among other popula- tions in the Florida reef tract, and between some Florida locations and the Bahamas. Similarly, gene flow occurs between populations in the South Caribbean Sea, but appears restricted between the Caribbean Sea and the Atlantic (Florida-Bahamas). Dispersal of C. delitrix was farther than expected for a marine sponge and favoured in areas where currents are strong enough to transport sponge eggs or larvae over longer distances. Our results support the influence of ocean current patterns on genetic connectivity, and constitute a baseline to monitor future C. delitrix trends under climate change.