| AGC 226067 is an intriguing source originally identified by its neutral hydrogen gas content (HI) in the ALFALFA HI survey with no apparent optical counterpart. Subsequent deep ground-based optical imaging revealed a blue fuzzy counterpart, identifying the system as a low-mass galaxy with an extremely high ratio of HI to stellar mass. Recently, a team led by Betsey Adams and including Tom Oosterloo used data from the VLA to show that the system consists of multiple components (both gas and stars) connected by low surface brightness HI. The image above shows the two main HI components in the white contours, and the red circles indicate the optical sources. Fully understanding the system will require better data but a likely explanation is that the main source (bottom of the image; gas and stars coincident with each other) is a dwarf galaxy undergoing some sort of interaction as it falls into the Virgo Cluster. Future surveys with Apertif will be able to detect many more systems like this one via their gas content.
You can find more details in AGC 226067: A possible interacting low-mass system, Adams, E. A. K., et al. 2015, A&A in press, http://arxiv.org/abs/1507.01855