Goldfish Anatomy
The Pearlscale is the only Goldfish variety with differently shaped scales. Rather than having the long slender body of the common Goldfish, the Pearlscale Goldfish has a fatter shape with a bulging middle. There is a hard, white, raised area in the middle of each scale and dark perimeters. It looks like a white pearl hence it is aptly named as Pearlscale.
There is only one dorsal fin and all other fins occur in pairs. Its dorsal fin stands erect on its back. Caudal fin should be forked and held high horizontally. The other fins of Pearlscale are paired with ends that are rounded, with lobes that appear forked at the tips. Whenever Pearlscale swims, these lobes often wave upwards instead of downwards. Its head has a triangular shape, some varieties have a bulbous cranial region.
They have a straight back with a swollen belly, resembling a golf ball. Depth of the body is at least 2/3 of the body length.
There is only one dorsal fin and all other fins occur in pairs. Its dorsal fin stands erect on its back. Caudal fin should be forked and held high horizontally. The other fins of Pearlscale are paired with ends that are rounded, with lobes that appear forked at the tips. Whenever Pearlscale swims, these lobes often wave upwards instead of downwards. Its head has a triangular shape, some varieties have a bulbous cranial region.
They have a straight back with a swollen belly, resembling a golf ball. Depth of the body is at least 2/3 of the body length.
Dorsal Fin
The dorsal fin gives the goldfish stability in the tank. Some goldfish have longer dorsal fins than other goldfish, while some goldfish have no dorsal fin at all. Another difference between the dorsal fin in goldfish can be the height. From Lionheads and Ranchus, that have no dorsal fin, to the veiltail variety of goldfish that can have a long dorsal fin. Goldfish with an average size dorsal fin a sign of good health is an upright dorsal fin, while the longer dorsal finned varieties of goldifsh it is regular to have a bend in the dorsal fin.
Caudal Fin and Anal Fin
The caudal fin, or tail fin, is used by the goldfish to move forward. These fins be different depending on the type of goldfish. Some goldfish have a single tail, while many fancy goldfish have double tails.
The anal fin on a goldfish helps keep the goldfish upright and stable, and is found just before the caudal fin on the lower portion of the goldfish body.
The anal fin on a goldfish helps keep the goldfish upright and stable, and is found just before the caudal fin on the lower portion of the goldfish body.
Pelvic Fin
The pelvic fins are located on both sides of the goldfish, in front of the anal fin, but behind the pectoral fin. These pelvic fins are used for both stability and steering.
Pectoral Fin
The pectoral fins are located on both sides of the goldfish just under and behind the gills. Pectoral fins in goldfish are used for forward and backward movement. During the spring months male goldfish will develop breeding tubercules along the leading ray of the pectoral fin, which can be stiff and thick.
Lateral Line
Running along the side of goldifsh, the lateral line is a sensory organ. The lateral line is extremely sensitive and can detect motion, current, pressure, and even sound.
Gill and Eye
The gills are the part of the goldfish that are used for breathing. The opening allows water to flow out of the mouth, past the gills, for breathing. During the spring males can be easily identified by the breeding tubercules that appear on the gill covers.
Most goldfish can see well, but some breeds that have telescoping eyes can have very poor vision.
Most goldfish can see well, but some breeds that have telescoping eyes can have very poor vision.