Rajiform or ray fish are mainly known for their dorsoventrally flattened body reminding us of a manta on many occasions. However, it is common to confuse these fish with the also known manta ray, which is not a rajiforme.
Taxonomy of ray fishes or rajiformes
Rays belong to the order Rajiformes of the class Elasmobranchios, a group of cartilaginous fish that includes other orders such as the Lamniformes (ex: mako shark), the Carchariniformes (ex: catshark) and the Torpediniformes (ex: torpedo fish). They are found within the vertebrate subphylum, since they have a backbone made up of vertebrae, unlike other chordates, such as those belonging to the tunicate or cephalochordate subphylum. The rajiformes differ from the bony fish in that the latter, as their name suggests, have a skeleton of bone and not cartilage.
There are numerous species with a structure similar to rays, such as the torpedo fish. However, this does not belong to the Rajiformes order, but to the Torpediniformes order. Therefore, it is important to know how to differentiate between rays and other cartilaginous fish.
Characteristics of striped or rajiformes fish
The pectoral fins of rays are very large and are not differentiated from the flattened body of the animal, which is why the ray has a similar appearance to that of a disco While in the ventral region it has the mouth and gill slits, on the back are the eyes and spiracles through which it obtains water to carry out breathing. On the back of the body protrudes a long whip-like tail with which it can facilitate the locomotion of the fish.
Although some rays are pelagic and move through all the seas and oceans in search of food, most species are benthic, that is, they live on the seabed. They usually camouflage themselves by burying themselves in the depths to avoid their predators (sharks, for example) and to hunt their prey when they are nearby. Rays feed on small animals such as some crustaceans, molluscs and other fish
As for reproduction, they are mainly viviparous, since they give birth to their live young directly. However, some specimens lay very characteristic eggs covered by a capsule that are normally rectangular in shape. It is common to find specimens on the beaches, since these animals usually reproduce near the coast.
Types of stripes or rajiformes
Although all stripes or rajiformes have a fairly similar appearance, currently it is possible to differentiate 3 types or families which, in turn, includes numerous different species:
- Family Rhinobatidae: Also known as “angelfish” or “guitarfish”. Includes rays that are characterized by their wider tail giving an appearance similar to the body of a shark. They have a large head, a rounded snout and are harmless. Within this family we can highlight the species Rhinobatos planiceps.
- Family Rajidae: includes benthic rays with a diamond-shaped body and a row of spines on the back that give it a bristly appearance to the skin. They generally have a short and thinner tail than the previous group. This family includes numerous species, among them we can highlight the Gurgesiella furvescens and the Amblyraja georgiana.
- Family Arhynchobatidae: the specimens of this family are characterized by having a shorter but very soft and flexible snout. Their tails are also thin and somewhat more slender. Species belonging to this family of rays are Bathyraja brachyurops and Rhinoraja multispinis.
Examples of species of rays or rajiformes
Now that you know what rays are like and what types there are, here are some examples of species of rays that you may find interesting.
Rhinobatos planiceps
They present a big head with remarkable eyes and spiracles on the top of it. Its body is slender, similar to that of sharks and it has two prominent dorsal fins. They are usually benthic animals, so they are mainly found on sandy bottoms.
And if you want to know more curious fish, we encourage you to read this other article about Fish with legs - Names and photos.
Gurgesiella furvescens
It is characterized by its fan-shaped body, with generally brown coloring and a differentiated tail, thin and long This species lives in deeper waters than other specimens and can reach sizes of up to 50 centimeters. Like the Rhinobatos planiceps species, it is harmless to humans.
Georgian Amblyraja
It belongs to the Rajidae family, like the previous species, however, these specimens have a more rhomboid body and a tail more short. They can reach more than 90 centimeters and also usually live in deep waters in the seas of countries such as Chile or Argentina.
Bathyraja brachyurops
This species, belonging to the family Arhynchobatidae, has a shorter and more pointed snout It has a shorter tail in proportion to its body and small spiracles on the surface of its head. As for their coloration, they usually adopt dark tones such as brown or gray with some other spots.
Did you know that not all fish have scales? Discover this other article about Fish without scales - Types, names and examples!
Rhinoraja multispinis
It is characterized by having a rounded body, a blunt snout and two dorsal fins near the end of its tail. In the dorsal region, which presents shades of brown with some lighter spots, you can see large number of spines This species can measure approximately 50 centimeters and lives in depths than 100 meters.
Other examples of ray species
Although most rays or rajiformes are very similar in terms of morphology and way of life, these are some more examples of species of rays that can be found on the seabed:
- Bathyraja schroederi
- Dipturus chilensis
- Rajella nigérrima
- Peruvian bathyraja
- Sympterygia bonapartii
- Dipturus trachyderma
- Sympterygia lima
- Rajella sadowskii
- Psammobatis scobina
- Amblyraja frerichsi
