Bigelow's ray (''Rajella bigelowi''), also called the chocolate skate or Bigelow's skate, is a species of cartligainous fish belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Rajidae, the hardnose skates. This species is found in the Western Atlantic Ocean.

Taxonomy

Bigelow's ray was first formallly described as ''Raja (Rajella) bigelowi'' in 1978 by the German

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

Matthias Stehmann Matthias is a name derived from the Greek Ματθαίος, in origin similar to Matthew. Notable people Notable people named Matthias include the following: Religion * Saint Matthias, chosen as an apostle in Acts 1:21–26 to replace Judas Isca ...

with its type locality given as the Northwestern Atlantic at 37°05'N, 74°20.6'W from the Columbus Iselin station 91 at a depth of . Stehmann originally proposed '' Rajella'' as a

subgenus In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

of ''

Raja Raja (; from , IAST ') is a noble or royal Sanskrit title historically used by some Indian subcontinent, Indian rulers and monarchs and highest-ranking nobles. The title was historically used in the Indian subcontinent and Southeast Asia. T ...

'', with '' Raja fyllae'' as its

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, but ''Rajella'' is now recognised as a valid genus within the family Rajidae. The family Rajidae is included in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Rajiformes Rajiformes is one of the four Order (biology), orders in the clade Batomorphi, often referred to as the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pector ...

, the skates.

Etymology

Bigelow's ray is classified in the genus ''Rajella'', a name which is a

diminutive A diminutive is a word obtained by modifying a root word to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment, and sometimes to belittle s ...

of ''Raja'', the genus it was originally proposed to be a subgenus of, given because of the relatively small size of its type species. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours the American

oceanographer Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of top ...

and

marine biologist Marine biology is the scientific study of the biology of marine life, organisms that inhabit the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology clas ...

Henry B. Bigelow of the

Woods Hole Oceanographic Institution The Woods Hole Oceanographic Institution (WHOI, acronym pronounced ) is a private, nonprofit research and higher education facility dedicated to the study of marine science and engineering. Established in 1930 in Woods Hole, Massachusetts, it i ...

in recognition for his work on cartilaginous fishes.

Description

Like all rays, Bigelow's ray has a flattened body with broad, wing-like

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s. The body is sub-rhomboid. It is dark on the dorsal surface, with the outer edges of the disc and pelvic fins shading to a slightly darker colour. Its maximum length is .

Distribution and habitat

Bigelow's ray has a disjunt distribution in the northern Atlantic. In the Western Atlanticit occurs from the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

north ro

New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...

and on the

Scotian Shelf The Scotian Shelf is a geological formation that is part of the continental shelf southwest of Nova Scotia, Canada. It covers an area of , is long, and has a width from . It has an average depth of . The Scotian Shelf contains the ecologically imp ...

Grand Banks The Grand Banks of Newfoundland are a series of underwater plateaus south-east of the island of Newfoundland on the North American continental shelf. The Grand Banks are one of the world's richest fishing grounds, supporting Atlantic cod, swordfi ...

and

Labrador Shelf Labrador () is a geographic and cultural region within the Canadian province of Newfoundland and Labrador. It is the primarily continental portion of the province and constitutes 71% of the province's area but is home to only 6% of its populatio ...

of Canada, and the French territory of

Saint Pierre and Miquelon Saint Pierre and Miquelon ( ), officially the Territorial Collectivity of Saint Pierre and Miquelon (), is a self-governing territorial overseas collectivity of France in the northwestern Atlantic Ocean, located near the Canada, Canadian prov ...

, and

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

. In the Eastern Atlantic it is found from the

Mid-Atlantic Ridge The Mid-Atlantic Ridge is a mid-ocean ridge (a Divergent boundary, divergent or constructive Plate tectonics, plate boundary) located along the floor of the Atlantic Ocean, and part of the List of longest mountain chains on Earth, longest mountai ...

and the

Rockall Trough The Rockall Trough () is a deep-water bathymetric feature to the northwest of Scotland and Ireland, running roughly from southwest to northeast, flanked on the north by the Rockall Plateau and to the south by the Porcupine Seabight. At the n ...

to the

Bay of Biscay The Bay of Biscay ( ) is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and along the northern coast of Spain, extending westward ...

and along the African coast at northern Morocco, the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

, Western Sahara and Guinea Conakry> Bigelow's ray lives on continental slopes and deepwater and has been recorded at , mostly below .

Behaviour

Bigelow's ray feeds on small benthic

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

Life cycle

Bigelow's ray is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

. The

eggs An egg is an organic vessel in which an embryo begins to develop. Egg, EGG or eggs may also refer to: Biology * Egg cell, the female reproductive cell (gamete) in oogamous organisms Food * Eggs as food Places * Egg, Austria * Egg, Switzerland ...

are oblong capsules with stiff pointed horns at the corners; they are deposited in sandy or muddy flats. It is parasitised by '' Ditrachybothridium macrocephalum'' (

tapeworms Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, commonly known as tapeworms. Their bodies con ...

of the order Diphyllidea).

References

External links

* {{Authority control bigelowi Fish of the Atlantic Ocean Fish of the Gulf of Mexico bigelows ray Taxa named by Matthias Stehmann