Undulate ray
Encyclopedia
The undulate ray, Raja undulata, is a species of ray
and cartilaginous fish
generally found along the southern coast
s of England
and Ireland
in depths of about 10 to 30 m (32.8 to 98.4 ) but have been found as deep as 200 metres (656.2 ft).
, and contains small prickle
s used for protection. The dorsal fin
s are quite far apart, normally with two dorsal spines between them. Median spines are scattered in adults, regular on young. The males have one lateral row each side, whereas the females have two, and the ray weighs about 10 pounds
but can reach to as much as 20 pounds (4.5 to 9 kg).
During late summer the females lay their eggs
. Each egg is within a leathery black eggcase known by the common name
"mermaid's purse
" (as are the eggcases of other rays, skates and sharks.) These "purses" often wash up on beach
es after rough weather, although usually they wash up empty, the young ray having already hatched out.
Batoidea
Batoidea is a superorder of cartilaginous fish commonly known as rays and skates, containing more than 500 described species in thirteen families...
and cartilaginous fish
Chondrichthyes
Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone...
generally found along the southern coast
Coast
A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...
s of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
and Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
in depths of about 10 to 30 m (32.8 to 98.4 ) but have been found as deep as 200 metres (656.2 ft).
Appearance
The undulate ray features a round disc-shaped headHead
In anatomy, the head of an animal is the rostral part that usually comprises the brain, eyes, ears, nose and mouth . Some very simple animals may not have a head, but many bilaterally symmetric forms do....
, and contains small prickle
Prickle
Prickle may refer to:*Prickle , a sharp, needle-like structure*Prickle cell of the skin*Prickle , a planar cell polarity protein*the collective noun for a pack of porcupines*Prickle , a character on The Gumby Show...
s used for protection. The dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s are quite far apart, normally with two dorsal spines between them. Median spines are scattered in adults, regular on young. The males have one lateral row each side, whereas the females have two, and the ray weighs about 10 pounds
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...
but can reach to as much as 20 pounds (4.5 to 9 kg).
Reproduction
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. Each egg is within a leathery black eggcase known by the common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
"mermaid's purse
Mermaid's purse
An egg case or egg capsule, colloquially known as a mermaid's purse or devil's purse, is a casing that surrounds the fertilized eggs of some sharks, skates, and chimaeras. They are among the common objects which are washed up by the sea. They are made of collagen protein strands...
" (as are the eggcases of other rays, skates and sharks.) These "purses" often wash up on beach
Beach
A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...
es after rough weather, although usually they wash up empty, the young ray having already hatched out.