Ranchu tail. The caudal peduncle itself should be broad and neither lengthy or too short (a properly formed caudal peduncle avoids swimming motion impairments to this type of goldfish). The ranchu's tail meets the caudal peduncle at a forty-five degree angle, giving the fish a unique swimming motion. Furthermore, the tail lobes are rounded, and all other finnage are paired. The most prominent feature of the ranchu is its head. There must be sufficient space between the eyes, and also from the eyes to the front of the head. The gill cover should figuratively extend quite far towards the tail. The
Houndfish ages. The houndfish also has a more stout, cylindrical body and a shorter head than other needlefishes. They have dark blue backs and silver-white sides and are plain white ventrally. A houndfish has a distinct keel on the caudal peduncle, and the caudal fin itself is deeply forked. Juvenile houndfish possess an elevated, black lobe on the posterior of their dorsal fins. The longest recorded houndfish was , and the largest recorded weight was . In the Indian and Pacific Oceans, houndfish are found in the Red Sea and from the coast of South Africa, east to French Polynesia, and