Atlantic Manta Ray
Manta birostris
Summary 2
The giant oceanic manta ray (Manta birostris) is a species of ray in the family Mobulidae, and the largest type of ray in the world. They are circumglobal and are typically found in tropical and subtropical waters, but can also be found in temperate waters.
Description 3
Common names: manta (English), mantarraya (Espanol), manta (Espanol)
Manta birostris (Walbaum, 1792)
Manta, Giant manta
Head relatively wide, projecting with a pair of paddle-like extensions; large triangular "wings" (pectoral fin flaps); mouth at front of head, relatively wide; teeth in lower jaw only; tail long and whip-like, without spines; disc above and below covered with small denticles.
Dark grey to black above, sometimes with white patches on shoulders; white on underside.
Size: to at least 8 m disc width and over two tons in weight.
Habitat: inshore and offshore pelagic.
Depth: 0-30 m.
Circumtropical; throughout our region except the northern Gulf of California.
Distribution 4
Gulf of Maine to Brazil, and occasionaly further north
Physical description 5
Manta rays are easily reconized in the ocean by their large pectoral "wings." Manta birostris have no dorsal or caudal fins. They have two cephalic lobes that extend from the front of the head and a broad, rectangular, terminal mouth containing small teeth exclusively in the lower jaw. The gills are located on the underside of the body. Manta rays also have a short, whip-like tail that, unlike many rays, has no sharp barb. Atlantic manta ray pups weigh 11 kg at birth and their growth is rapid, with pups virtually doubling the body width from birth through the first year of life. Manta rays show little dimorphism between the sexes with wingspan in males ranging from 5.2 - 6.1 meters and females ranging from 5.5 - 6.8 meters. The largest ever recorded was 9.1 meters. One of the distinct features of manta rays, and of the class Chondrichthyes, is that the entire skeleton is made of cartilage, which allows for a wide range of motion. These rays vary in color from black to grayish blue along the back, and a white underside with grayish blotchs that have been used to identify individual rays. The skin of manta rays is rough and scaly, like that of most sharks.
Range mass: 1200 to 1400 kg.
Other Physical Features: ectothermic ; bilateral symmetry
Sexual Dimorphism: female larger
Size 6
Maximum size: 7000 mm WD
Description 7
Mainly oceanic (Ref. 7251) but also encountered in surface or mid-waters of lagoons, shallow muddy bays, off river mouths, and seaward reefs. Occurs singly or in small groups (Ref. 1602). Mainly plankton feeders, but may feed on small and moderate-sized fishes as well (Ref. 9911). Mantas are not aggresive but are dangerous because of their rough skin and huge size which has led to the deaths of deep-sea divers whose airlines have been entangled with these creatures. May be captured by means of the harpon. Leaps out the water every once in a while.
I dnature guides 8
Identification key for shorefishes of the tropical eastern Pacific
Habitat 9
Habitat Type: Marine
Diet 10
Feeds mainly on plankton, may consume small fishes
Life cycle 11
Exhibit ovoviparity (aplacental viviparity), with embryos feeding initially on yolk, then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus, fat or protein through specialised structures (Ref. 50449). Bears up to 2 young (Ref. 5578); born at 122-127 cm WD (Ref.58048). A female of 550 cm width and weighing 1050 kg was collected in the Galapagos in June and was carrying a well-developed embryo of 12.7 kg (Ref. 28023). Size at partuition might be from 1.1 to 1.3 m and from 9.1 to 1.14 kg (Ref. 31742).Yano et al (1999) (Ref. 35892) describe the mating behavior of manta rays based on observations off Ogasawara Islands, Japan, in the following sequence:1) 'chasing', the male rapidly follows behind the tail of the female and attacks her several times;2) 'nipping', the male nips the tip of the pectoral fin of the female and then moves to the ventral surface of the female;3) 'copulating', the male inserts a clasper into the cloacaof the female and copulates abdomen-to-abdomen, up to 123 seconds;4) 'post-copulating';5) 'separating'. (Ref. 49562).
Reproduction 12
Manta birostris are sexually mature at 5 years of age. The mating season of sexually mature manta rays occurs from early December to late April. Mating takes place in tropical waters (26-29 degrees Celsius), and around rocky reef areas from 10-20 meters in depth. Manta rays gather in large numbers during this season, where several males will court a single female. The males swim closely behind the tail of the female at faster than usual speeds (9-12km/h). This courtship will last for about 20-30 minutes at which point the female decreases her swimming speed and a male will grasp one side of the female's pectoral fin by biting it. He arranges his body under that of the females. The male will then insert his clasper in the cloaca of the female and insert his sperm, this usually lasting around 90-120 seconds. The male will then swim away rapidly and the next male will repeat this same process. However, after the second male the female usually swims away leaving behind the other courting males. The gestation period of Manta birostris is 13 months, after which females give birth to 1 or 2 live young. Pups are born wrapped up by their pectoral fins, but soon after become free swimmers and fend for theirselves. Manta ray pups are between 1.1 and 1.4 meters when they are born.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization (Internal ); viviparous
Average age at sexual or reproductive maturity (female)
Sex: female: 2190 days.
Functional adaptation 13
Fins funnel food: manta ray
The mouth of manta rays filter feeds more efficiently because food is funneled via extendable, flaplike fins on either side of the mouth.
"The manta is the largest living ray, up to 6.7 metres across and 1360 kg in weight. Surprisingly, it feeds on small crustaceans and plankton, trapped on its gill rakers. Unlike most rays, its mouth extends across the front of its body, and the large mobile pale-coloured cephalic fins on either side of the mouth can be extended vertically. It has been suggested that these may form a scoop or funnel leading to the mouth while feeding." (Foy and Oxford Scientific Films 1982:188)
Learn more about this functional adaptation.
Link to Access Genomic Data 14
http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=195310&lvl=0
Sources and Credits
- (c) Mark Rosenstein, some rights reserved (CC BY-NC), uploaded by Mark Rosenstein
- Adapted by matbio from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Manta_birostris
- Adapted by matbio from a work by (c) Shorefishes of the tropical eastern Pacific online information system. www.stri.org/sftep, some rights reserved (CC BY-NC), http://eol.org/data_objects/26219517
- Adapted by matbio from a work by (c) WoRMS for SMEBD, some rights reserved (CC BY), http://eol.org/data_objects/28471482
- Adapted by matbio from a work by (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18657011
- Adapted by matbio from a work by (c) FishWise Professional, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/24179110
- Adapted by matbio from a work by (c) WoRMS for SMEBD, some rights reserved (CC BY), http://eol.org/data_objects/28495805
- Adapted by matbio from a work by (c) Discover Life and original sources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11586356
- Adapted by matbio from a work by (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28869035
- Adapted by matbio from a work by (c) WoRMS for SMEBD, some rights reserved (CC BY), http://eol.org/data_objects/28476550
- Adapted by matbio from a work by (c) FishBase, some rights reserved (CC BY-NC), http://eol.org/data_objects/20923558
- Adapted by matbio from a work by (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18657012
- Adapted by matbio from a work by (c) The Biomimicry Institute, some rights reserved (CC BY-NC), http://eol.org/data_objects/16885057
- (c) matbio, all rights reserved
