Fish that do not have scales include catfish, sharks, rays, chimaeras, skates, moray eels, sturgeons, paddlefishes, salifin blennies, combtooth blennies, hagfishes and lampreys. Many of these fish have evolved scale alternatives.Know More
Cartilaginous fishes like sharks and rays not only lack scales, they also lack bones. Their skeletons consist of cartilage, which is flexible and allows some of them to grow to enormous size. The whale shark is the largest fish on earth and can grow to 30 feet long. The manta ray is also a huge animal that can be over 22 feet across and weigh over 3,000 pounds. Instead of the scales that other fish possess, these fish have denticles, which are basically tiny teeth that make their hides feel like sandpaper.
Sturgeons are fish that have scutes instead of scales. These are bony plates that are more often seen in crocodilians. They can also grow to a great size and live to a great age. The average lifespan of the lake sturgeon is about 82 years.
Lampreys are primitive fish. They have round, jawless mouths lined with rows of teeth. Some are parasites that grab on to another fish with their mouths, rasp a hole in the flesh and feed on bodily fluids.Learn more about Fish
Fish that are high in omega-3 fatty acids are fatty, coldwater fish such as salmon, tuna, black cod, tilefish, halibut, swordfish, mackerel, anchovies, sardines, trout and herring. Omega-3 fatty acids are polyunsaturated fats that can help prevent cardiovascular disease and reduce the risk of other diseases.Full Answer >
Fish that can coexist with goldfish include white cloud minnows, rosy red minnows, rosy barbs, charming weather loaches, zebra danios, tetras, guppies, wimples and other goldfish. Goldfish may eat smaller fish, so potential companions should be of comparable size to their goldfish tank mates.Full Answer >
Fish is an excellent source of iron, according to the Centers for Disease Control and Prevention. The iron found in fish and other meats is absorbed in the body nearly two to three times faster than the iron found in plants.Full Answer >
The scales of bony fish grow out of the dermis and are embedded in the dermis at the base of the scale. They overlap like shingles on a roof, says The Earth Life Web. Most bony-fish scales have two layers: a calcified layer on the bottom and a fibrous layer on the top. Fish don't shed their scales; the scales continue to grow with the fish.Full Answer >