Description:

Large devil ray with a very broad and short disc (approximately 2.2-2.4 times broad as long). Dorsal surface black with paler to white shoulder patches curving inwards 
from spiracles.

Ventral surface white with variable dark blotches/spots; small black semi-circular spot emanating from the fifth gill slits. Nob like denticles on dorsal and ventral 
surfaces give rough texture. Dorsal fin small and triangular. Tail longer than disc, if intact, and bears no spine. Very broad and terminal mouth lower jaw with tooth band.

Size:

Maturity: males mature at ~ 300cm DW, females at ~390cm DW. Max size: Attains ~ 500cm DW
 

Habitat and Ecology:

Benthopelagic; mainly inshore around coral and rocky reefs, and areas associated with upwellings, depth range 1 - 120 m. Diet consists primarily of planktonic organisms and 
probably small bony fishes. Low fecundity producing a single pup (occasionally 2) typically every second year after a gestation period of 12-13 months.
 

Fishery Status:

This species is not protected or subject to fishery regulations despite being an Appendix I species under the Convention on Migratory species to which Seychelles is party. 
It is caught in gill nets, or very occasionally harpooned, but is a rare component of the artisanal catch. 
 

Notes:
References:

Froese, R. & D. Pauly. Eds. (2018). FishBase. https://www.fishbase.de/summary/Mobula-alfredi (25/08/18).
Last, P.R. et al (2016). Rays of the World. CSIRO Publishing ISBN 9781501705328
Marshall, A. et al (2019). Mobula alfredi. The IUCN Red List 2019: e.T195459A68632178. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T195459A68632178.en. (29/09/21).

Citation:

Nevill, J.E.G. (2019). Mobula alfredi, Reff Manta ray. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/mobula-alfredi-krefft-1868/ (Updated 29/09/21).