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
Squalidae Squalidae The Squalidae, also called dogfish sharks or spiny dogfishes, are a family of sharks in the order Squaliformes. They have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. Unlike virtually all other shark species, dogfish sharks possess venom which coats their dorsal spines – this venom is mildly toxic to humans. These sharks are characterized by teeth in upper and lower jaws similar in size; a caudal peduncle with lateral keels; the upper precaudal pit usually is present; and the caudal fin is without a subterminal notch.