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MANTA RAY UPDATE It's official, there are now two manta ray species in Hawaii!

According to a 2009 paper by Andrea D. Marshall, Leonard J.V. Compagno, and Michael B. Bennett, the genus Manta consists of at least two species, both of which are present in Hawai`i. The common coastal species, previously called Manta birostris, is now Manta alfredi. The less common pelagic species is Manta birostris


PELAGIC MANTA Manta birostris (Walbaum, 1792)
Only occasionally reported in Hawaiian waters, this manta seems to be more pelagic in its habits than the Coastal Manta. (One individual, for example, was photographed off Kona in 2006 and later off Maui in 2009. No one knows where it was between the two sightings.) Characters for field identification are: 1) Bright white shoulder patches are always present and usually have a backward facing "hook" on outer side . 2) Front edge of white shoulder patch is parallel with front edge of mouth. 3) No black spots or marks occur in the "chest" area between the two pairs of gill slits on the underside. 4) A wide gray margin always present along rear edge of the wings on the underside. 5) The mouth area is dark gray or black (best seen from below or when viewed head-on). In addition, there is a small spine at the base of the tail which is almost completely embedded in a knoblike bony mass, difficult to see underwater. A few individuals are all black except for a white blaze in center of underside. This is the largest manta, attaining at least 24½ ft. wingtip to wingtip.

For more photos of Pelagic Mantas copy and paste this search into Google:
pelagic manta site:mantapacific.org

COASTAL MANTA Manta alfredi (Krefft, 1868)
This by far the most commonly-seen of Hawaii's two manta species. it generally remains within a mile or so of shore and is not known to travel from island to island. Characters for field identification are: 1) Pale to white shoulder patches usually present, always with a small bright white spot on the leading edge (marking the spiracle, or opening where water is drawn into the gills). 2) Black spots or markings are almost always present in the "chest" area between the two pairs of gill slits on the underside. 3) The mouth area is whitish or grayish (best seen from below or when viewed head-on). In addition, there is no spine at the base of the tail. (This character is not detectable except perhaps at very close range.) A few individuals are entirely black except for a white blaze mark on the underside. Manta alfredi grows to a maximum of about 18 ft. from wingtip to wingtop. It occurs throughout the Indo-Pacific, but is not recorded from the Eastern Pacific. All the manta photos in my books are Coastal Mantas.

For more information, see:

Marshall, A.D., L.J.V. Compagno, M.B. Bennett, 2009. Redescription of the genus Manta with resurrection of Manta alfredi (Krefft, 1868) (Chondrichthyes; Myliobatoidei; Mobulidae) Zootaxa 2301: 1-28 (2009)

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Text and photos (except those labeled otherwise) copyright by John P. Hoover