Batomorphi is a superorder of cartilaginous fishes. The body is flattened. On the ventral side of the body has 5 pairs of gill slits. Anal fin is absent. Pectoral fins are strongly developed. Dorsal fins are underdeveloped or absent. 5 detachments, 15 families (rhombus, shark-tailed, disk, tailfin, eagle, electric, manta, etc.), more than 315 species. Predominantly marine fishes, living in all seas and oceans. Some live in tropical rivers, others, inhabiting the coastal shallows of all oceans, enter desalinated estuaries. Bottom fish, only a few live in the water column (mantas, tailfins). They range in size from 12-15 cm to 6-7 m in length. Bentophagous and predators. Live-bearing and oviparous, some lay large, encapsulated eggs (sea fox). Batomorphi are fished.
The skin is bare or covered with spines. The skeleton is cartilaginous. Head and trunk flattened dorsally and ventrally; in most Batomorphi they merged with sprawling pectoral fins, forming a disk. Gill openings of 5 pairs are located on the ventral side of the body. Dorsal fins are located on the tail (in some species they are absent). Batomorphi are usually viviparous or oviparous (i.e., the juvenile hatches from the egg at the time of its laying); only common S. lay eggs. Duration of egg development is from 4.5 to 15 months. Fecundity from 1 to several dozen fry (sawfish). Most feed on bottom animals; some feed mainly on mollusks.
Inhabit all seas and oceans, and live both in the cold waters of the Arctic and Antarctic, and in the tropics, the temperature range of their habitat ranges from 1.5 to 30 ° C. These fish are found both in shallow waters and at depths up to 2700 meters. Most species lead a benthic lifestyle and feed on mollusks, crayfish and echinoderms. Pelagic species feed on plankton and small fish.
The size ranges from a few centimeters to 6-7 m in length. One of the best known species of Batomorphi is Manta birostris. Larger sizes are reached by Batomorphi of the eagle family, whose fin spread can reach 2.5 meters and length up to five meters; and Batomorphi of the tail-fin family, reaching 2.1 meters in width and up to 5.5 meters in length. The comparatively large stingray-tailed sea cat is found in the Black Sea and the Sea of Azov.
Many species have reduced scales. Others, like sharks, have placoid scales, the oldest type of scales. Scales are rhombic plates that end in a spike protruding from the skin to the outside. In structure and strength scales are close to teeth, which gives reason to call it skin teeth. These teeth have a broad base, flattened shape and very relief outlined crown. The spike of placoid scales is characterized by high strength, as it is covered with an analog of enamel - vitrodentine, formed by cells of the basal layer of the epidermis. The placoid scale has a cavity filled with loose connective tissue with blood vessels and nerve endings. In some species of Batomorphi, the placoid scales are modified and appear as large plaques on the body surface (e.g., Raja clavata) or barbs (e.g., Pteroplatytrygon violacea).
Batomorphi (like other cartilaginous fishes) have well developed three groups of sensory organs: organs of chemical receptivity (parallel to olfaction and taste of terrestrial animals), photoreception (vision) and organs of acoustic-lateral system (lateral line organ, ampullae of Lorenzini). Accordingly, the Batomorphi brain has three distinct sections: anterior, responsible for chemical receptivity (olfactory bulb and olfactory lobe), middle, responsible for vision (optic tubercles) and posterior section (including medulla oblongata and cerebellum), which processes signals coming from the organs of the acoustic-lateral system. The degree of development of each brain section is related to the ecological role of the corresponding sensory complex for a given species. It should be noted that Batomorphi, like other aquatic cold-blooded animals, have a high degree of autonomy of the spinal cord.
Some Batomorphi have organs that produce electricity. They are paired symmetrical structures located laterally, consisting of electric plates assembled in columns. In Batomorphi their weight reaches 25% of the weight of the fish, in appearance they resemble bee honeycombs. One organ is made up of about 600 vertically placed hexagonal prisms. Each prism, which is a kind of battery, in turn consists of 40 or less electric disk-shaped plates, separated by jelly-like connective tissue. In Batomorphi, the electrical organs are located in the caudal part of the body.
Batomorphi are separate-sex animals. Reproduce or laying on the bottom encapsulated eggs, or oviparity (the baby hatches from the egg at the time of its laying). Fecundity Batomorphi ranges from one to several dozen fry (in the sawfish). It takes 4.5 to 15 months from laying to hatching of the eggs. In electric Batomorphi and tailfins in the uterus additionally develop special villi, or trophotenia, which supply the embryo with nutrients.