2025/05/16 by Miriam Steinitz‐Kannan, Jerry H. Carpenter, Mark A. Nienaber · 1 voice · 1 citation
Earth and Planetary Sciences · Engineering · Materials Science · #Diatoms and Algae Research #Marine Biology and Ecology Research #Marine Biology and Environmental Chemistry
paper · pdf · doi:10.3897/subtbiol.51.141192
openalex publication_date 2025/05/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
The rare endemic brittle star Amphicutis stygobita (Echinodermata: Ophiuroidea: Amphilepididae) is found in Bernier Cave on San Salvador Island in The Bahamas. We report here on the diatom-rich detritus on which the brittle star feeds. The detritus contains a microbial biofilm dominated by a large diatom Campylodiscus neofastuosus Ruck & Nakov that thrives in the cave’s brackish water. The biofilm diatoms and bacteria produce sticky, carbohydrate-rich, extracellular polymeric substances (EPS) that add to the detritus’ nutritional value and help give the detritus a consistency for A. stygobita to pull it into its mouth. Of particular interest is that Campylodiscus neofastuosus has distinct cell wall features that make efficient use of the limited light in the cave. It appears these morphological adaptations might focus light onto the chloroplasts increasing light capture. Furthermore, large, dark, and highly lobed chloroplasts serve as an additional low-light adaptation. This is a rare instance where efficient photosynthetic activity by diatoms produces a complex biofilm that feeds an endemic cave species population.