When inspected side-by-side, C. briggsae and C. elegans are almost indistinquishable, even though they diverged from their last common ancestor approximately 100 million years ago. C. briggsae shares many of the same features that have made C. elegans a model organism for the study of genetics, as developmental biology, neurobiology, cell biology and behavior: it is easy to maintain in the laboratory, has a short generation time, an invariant anatomy and transparent body. Again, like C. elegans, the C. briggsae embryo goes through four larval stages before becoming a mature adult. Each larval stage looks similar to the adult, only smaller. C. briggsae can adapt an alternative life form, call a dauer larva, in response to overcrowding or the absence of adequate food supply. This dauer larva can remain viable for as long as three months, while it roams around in search of food. It is this dauer larvae that is the most common form of C. briggsae found in the wild. The adult is a self-fertilizing hermaphrodite, meaning it is both a male and female. When it first becomes and adult it is a male, which produces sperm that it then stores. Next, it becomes a female and produces eggs, which are then fertilized by the stored sperm. C. briggsae's genome is slightly larger than C. elegans' (104 Mb for briggsae vs. 100 Mb for elegans). It is slightly larger than C. elegans', but 30 times smaller than the human genome. The genome encodes ~22,000 proteins.
Caenorhabditis briggsae is a small, free-living, nematode that, like its close and more famous relative C. elegans, is found in nutrient- and microorganism-rich habitats such as in compost, mushroom beds and garden soil where it feeds on bacteria. It has been isolated from soil in temperate regions around the world. It has been found in association with other closely related species. Since their habitats are essentially identical, C. briggsae is sometimes found co-occurring with C. elegans and C. remanei. Also like C. elegans, C. briggsae has been found associated with other invertebrates like snails, probably using their host as a form of transportation to new food sources.
A high-quality draft genome sequence, estimated to cover 98% of the C. briggsae genome, has been completed. That sequence and a comparison to the C. elegans' genome were published in 2004. The National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), provided the funding for sequencing the C. briggsae genome.