During the day, tubifer cardinalfishes (Siphamia tubifer) can be found darting among the needly spines of urchins on reefs across the Indian and Pacific Oceans. At night, they become bolder, perhaps because of their partnership with luminous Photobacterium mandapamensis bacteria. Thanks to the microbes, in the dark, these fish gently glow—light that scientists suspect creates predator-confusing countershading.
This partnership has made the fish and bacteria an emerging model for symbioses between microbes and vertebrates. Because the bacteria are housed in an organ that’s connected to the fish’s intestines, the mutualism shares similarities with gut microbiome symbioses. Research to date has been hampered by a lack of genomic resources for the fish, but that changed March 29 with the publication of a chromosome-level genome assembly for the cardinalfish in Genome Biology and Evolution.
To put together the fish’s 23-chromosome, 1.2 Gb genome, California Academy of Sciences evolutionary ecologist Alison Gould and ...
