| Common names: devil ray (English), mobula (English), manta (Espanol) |
Mobula munkiana Notabartolo di Sciara, 1987
Munk's mobula, Munk's devil ray, Pigmy devil ray
Disc strongly rhomboidal, much wider than long; wings strongly pointed; head wide, projecting from disc; pectoral fins extend along head and form two large soft horns; front margin of the pectoral fin ends above and before spiracle; eyes and spiracles on side of head; mouth ventral; small teeth on both jaws; length of tooth bands 54-65% of mouth width; teeth wider than long, smooth tips; ~ triangular filter plates in gills separate at tips; tail long, slender with small dorsal fin at base, a little shorter than disc width, with compressed base and without spine.
Upper surface black, purple or purplish grey; lower surface white, with outer half of pectorals blue-grey.
Size: 110 cm wide.
Habitat: schooling, pelagic in coastal and oceanic waters.
Depth: to 30 m.
Gulf of California to Peru; the Galapagos, Cocos and Malpelo.
Global Endemism: All species, East Pacific endemic, Tropical Eastern Pacific (TEP) endemic
Regional Endemism: All species, TEP endemic, Continent + Island (s), Continent, Island (s)
Climate Zone: North Temperate (Californian Province &/or Northern Gulf of California), Northern Subtropical (Cortez Province + Sinaloan Gap), Northern Tropical (Mexican Province to Nicaragua + Revillagigedos), Equatorial (Costa Rica to Ecuador + Galapagos, Clipperton, Cocos, Malpelo)
Inshore/Offshore: Offshore, In & Offshore, Inshore
Water Column Position: Surface, Near Surface, Water column only
Habitat: Water column
FishBase Habitat: Pelagic
Habitat and Ecology
Most of the fragmentary information available on the species is derived from the work of Notarbartolo-di-Sciara (1987, 1988) in the southern Gulf of California, México, though this species has been recently observed during artisanal fishing camp surveys throughout the Gulf of California (R. Hueter et al. unpublished data, Bizzarro 2001). Migrations are likely driven by temporal changes in water temperature with local movements presumed to be associated with the distribution and abundance of planktonic crustaceans, especially mysid shrimp (Mysidium spp.). Mysids are believed to be the dominant prey item of this species, at least during winter months. However, these conclusions are drawn from a very limited sample size (n=3) and through inference with a closely related, similar-sized mobulid from Africa (M. rochebrunei) and as such should be considered speculative (Notarbartolo-di-Sciara 1988, J. Bizzarro pers. obs). Gastropod shells and coral fragments have been found in stomach contents (presumed taken incidentally), indicating that unlike other eastern Pacific mobulids, benthic foraging may be common (Notarbartolo-di-Sciara 1988). This species may live in large aggregations consisting of several schools that move locally or regionally between prey patches. Occurrence of large schools in the northern Gulf of California are likely confined to summer months, though it has been reported in low numbers throughout the year in the southern Gulf of California (Notarbartolo-di-Sciara 1988, Bizzarro 2001, J. Bizzarro unpublished data). Mobula munkiana is not thought to segregate by gender, but may segregate by size (Notarbartolo-di-Sciara 1988). Observations and catches of the species often occur in pulses as it may be abundant in an area for only a few days and then not be observed locally for weeks or months (Notarbartolo-di-Sciara 1988, Villavicencio-Garayzar 1991, J. Bizzarro pers. obs). These movements have likely influenced the contrasting conclusions of M. munkiana abundance in the southern Gulf of California (Notarbartolo-di-Sciara 1988, Villavicencio-Garayzar 1991). Frequent benthic association of this species would also account for its irregularity in pelagic gillnet landings.
Location of copulation is unknown, but partruition has been reported in Bahía de La Paz during May and June (Villavicencio-Garayzar 1991). Although data is limited, sexual maturity of males is thought to occur at ~87cm DW based on an increase in clasper size and hardening of the clasper cartilage (Notarbartolo-di-Sciara 1988), with females maturing at 97cm DW (Villavicencio-Garayzar 1991). The reproductive mode is aplacental viviparity and embryos feed initially on yolk, then through absorption of enriched uterine fluid from the mother (Wourms 1977). Only the left ovary is functional and reports indicate that a maximum of one pup is estimated to be produced (Villavicencio-Garayzar 1991). Reproductive periodicity is unknown and there is no information on age and growth for this species.
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (disc width): Female: 97 cm DW (Villavicencio-Garayzar 1991); Male: ~87 cm DW (Notarbartolo-di-Sciara 1988).
Longevity (years): Unknown.
Maximum size (disc width): 110 cm DW (Notarbartolo-di-Sciara 1987).
Size at birth: 35 to 36 cm DW (estimated from related species by Notarbartolo-di-Sciara (1988), verified by Villavicencio-Garayzar (1991).
Average reproductive age (years): Unknown.
Gestation time (months): Unknown.
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: 1 pup/litter (Villavicencio-Garayzar 1991).
Annual rate of population increase: Unknown.
Natural mortality: Unknown.
Diet: Pelagic crustacea, zooplankton, pelagic fish eggs, pelagic fish larvae, bony fishes
Life History and Behavior
Molecular Biology and Genetics
Statistics of barcoding coverage: Mobula munkiana
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
CITES: Not listed
IUCN Red List Assessment
Red List Category
Red List Criteria
In northern Gulf of California artisanal fishery surveys during 1998 and 1999, M. munkiana were observed to be landed in large numbers at several camps. As catches in the more southerly camps decreased, those in the north increased, suggesting that large portions of the schools may be taken during the unknown movement patterns of this highly mobile species. The species was directly targeted during these times and dominated the elasmobranch landings (J. Bizzarro and W. Smith unpublished data, Bizzarro 2001). However, although catches consist of hundreds of individuals per day when the species is present, artisanal fishermen indicate that the presence of the ray is somewhat unpredictable.
Notarbartolo-di-Sciara (1988) described an active mobulid fishery operating from several artisanal fishing camps in and around Bahía la Ventana, Baja California Sur, México. Mobula munkiana, though taken, was not an abundant species in landings (9% of observed mobulid catches). Recent fieldwork in this region (June 2001), however, showed that this fishery is still active and that M. munkiana was the dominant mobulid landed, at least at the time of surveys (J. Bizzarro unpublished data). This species was landed with gillnets of 10?12?, typically set at the surface, but also throughout the water column.
Mobula munkiana is not likely to be able to tolerate high catch levels, given its low reproductive potential. Increasing demand for mobulid products in Asia, which may result in increased targeting in Central America, is of great concern.
In México, a moratorium on the issue of elasmobranch fishing permits was issued in 1993, but no formal management plan has been implemented for Mobula munkiana specifically or most other chondrichthyans. However, legislation is currently being developed in México to establish national elasmobranch fishery management. Elasmobranch fisheries are unmanaged throughout Central America, and attempts to regulate fisheries in Central America would greatly improve conservation of M. munkiana and other chondrichthyans.
Elasmobranch landings in México and Central America lack species-specific details with batoids broadly grouped as ?manta raya?. Improved clarity in catch records would provide a basis for detecting potential trends in effort and landings.
The development and implementation of management plans (national and/or regional e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA?Sharks) are required to facilitate the conservation and sustainable management of all chondrichthyan species in Central America.
The vulnerability of mobulids and increasing demand/catches requires urgent international conservation measures. These will need to focus on harvest and trade management.
Relevance to Humans and Ecosystems
Manta de monk
Mobula munkiana, the manta de monk, Munk's devil ray, pygmy devil ray, or smoothtail mobula, is a species of fish in the Myliobatidae family. It is found in Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, and Peru. Its natural habitats are shallow seas and subtidal aquatic beds.
- Bizzarro, J.J., Smith, W.D. & Clark, T.B. 2005. Mobula munkiana. 2006 IUCN Red List of Threatened Species. Downloaded on 3 August 2007.
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