Solemyids are remarkable in that their digestive tract is either extremely small or non-existent, and their feeding appendages are too short to reach outside the shell.[3]
It has been shown that these clams host sulphur-oxidizingbacteria intracellularly within their gill filaments. As chemoautotrophs, these bacterial symbionts synthesize organic matter from CO2 and are the primary source of nutrition for the whole organism.[4][5] In turn, the animal host provides its symbionts a habitat in which they have access to the substrates of chemoautotrophy (O2, CO2, and reduced inorganic compounds such as H2S). Together, these partners create "animals" with novel metabolic capabilities.
^Stewart, Frank J.; Cavanaugh, Colleen M. (2006). "Bacterial endosymbioses in Solemya (Mollusca: Bivalvia)—Model systems for studies of symbiont–host adaptation". Antonie van Leeuwenhoek. 90 (4): 343–360. doi:10.1007/s10482-006-9086-6. PMID17028934. S2CID351963.