The spinetail devil ray (''Mobula japanica''), also known as the spinetail mobula ray or Japanese mobula ray, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

marine fish which belongs to the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Mobulidae The Mobulidae (manta rays and devilfishes) are a family of rays consisting mostly of large species living in the open ocean rather than on the sea bottom. Taxonomy The Mobulidae have been variously considered a subfamily of the Myliobatidae by ...

. It is found throughout the

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and sub-tropical waters of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

and eastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

Taxonomy

Some analyses suggest that the species should be considered conspecific with the devil fish (''Mobula mobular''). It is no longer recognised as a species by the IUCN.

Description

The spinetail mobula ray is a large

ray Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (g ...

which can grow up to a maximal width of 3.1 m (average width 2.3 m). Like most rays, it is dorsoventrally flattened and has relatively large triangular pectoral fins on either side of the main body disc. At the front, it has a pair of cephalic fins which are forward extensions of the pectoral fins. These can be rolled up in a spiral for swimming or can be flared out to channel water into the ventral mouth when the animal is feeding. The background body coloration of the dorsal side is deep blue-mauve with a large black band stretches from eye to eye. The ventral side is white. The inner surface of the cephalic fins are silver-grey with black tips, while the outer surface and side behind eye are white. The species can be distinguished from other large rays by its projecting head, a white-tipped dorsal fin, a spine between the base of the dorsal fin and the start of the tail, and the length of its tail. Its spiracle is just above the area where the pectoral fin meets the body.

Distribution and habitat

Little information exists about the distribution of this species. It is assumed to have a circumglobal distribution in tropical and temperate waters, both inshore and offshore and fully oceanic. The southern Gulf of California appears to be an important mating and pupping ground.

Biology

The spinetail mobula ray has a

lifestyle and has been observed both alone and in groups. It feeds on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

by filtering sea water. As all

, species is

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

. After mating, the fertilized eggs develop within the female's oviduct. At first, they are enclosed in an egg case while the developing embryos feed on the yolk. After the egg hatches, the pup remains in the oviduct and receives nourishment from a milky secretion. The pup is 70–85 cm in disc width at birth.

Conservation status

In recent years, fishing for

has received a significant boost by price increases for their gill rakers in the market for

traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of action ...

. In addition to targeted catches, the species is also subject to losses from bycatch, particularly in the gillnet fishery. As such sustained losses have a high impact on a species which has a low fecundity rate, a long gestation period with only a single offspring at a time, and late sexual maturity, the spinetail mobula ray has been classified as

Near Threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

References

{{Taxonbar, from=Q1754242 Mobula Fish of Japan Pantropical fish Fish described in 1841 Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN