Rochen

Rochen is the German term for rays, a diverse group of cartilaginous fishes within the subclass Elasmobranchii. They are characterized by a dorsoventrally flattened body and enlarged pectoral fins that extend from the head, forming a disc- or ray-like shape. Most species inhabit marine environments, from shallow coastal waters and coral reefs to the deep ocean, with some groups able to tolerate brackish or fresh water.

Anatomy and senses: Rochen have skeletons made of cartilage rather than bone. They possess gill slits on the ventral surface, eyes on the upper surface, and tails that are often whip-like. Many species carry a venomous spine on the tail, a defensive adaptation in some groups. They also have electroreceptors, the ampullae of Lorenzini, which help detect prey and navigate their surroundings.

Diet and behavior: Rochen are primarily benthic feeders. Their diets commonly include mollusks, crustaceans, and small fishes, though larger species such as manta rays are filter feeders that consume plankton. Behavior ranges from slow, sweeping bottom foraging to long-distance migrations in larger species.

Reproduction: Modes vary within the group. Some rays are viviparous, giving birth to live young after internal gestation, often with placental nourishment. Others, such as many skates, are oviparous and lay eggs enclosed in protective capsules.

Taxonomy: In current classifications, rochen span multiple orders within Elasmobranchii, notably Rajiformes (skates and some rays) and Myliobatiformes (stingrays, manta rays and relatives). The term encompasses numerous families and hundreds of species, including common stingrays and manta rays.

Conservation: Many ray species face threats from commercial fishing, bycatch, habitat degradation, and pollution. Conservation measures include stock assessments, bycatch mitigation, marine protected areas, and, for some species, listing under CITES.