The galaxy immediately above the Whale is NGC 4627. Probably the two are interacting gravitationally, and this may explain the asymmetrical appearance of each. Together they are cataloged as #281 in Halton Arp's Atlas of Peculiar Galaxies. I'd say if NGC 4631 is the Whale Galaxy then NGC 4627 is the Remora.
The image itself has a peculiar shape. I took two sets of sub-frames, one in March and one in April. The camera was placed at a slightly different angle with respect to the telescope in March than in April. So I had edge lines in the final image. Normally, I would crop all those out, but I wanted to show all of the little galaxies floating about in this part of the sky, especially the irregular galaxies, so I selected around all of them, then added a darker layer outside of the selection. Exploring in this image is pretty fun. You might compare the full resolution image to what is shown for this area in sky-map.org, linked at right. The dimmest stars in this image are magnitude +18.5.
Telescope: Astro-Tech AT111EDT and William Optics AFR-IV (eff. at f/5.6)
Camera and Exposure: SXVF-H9 (104x480" (13.86 hours)), Alnitak Flat-man flats
Filter: Astronomik CLS
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX