Mobula or Baby Manta Ray
Posted 16 August 2012 - 12:49 PM
How can you tell between a Mobula Ray and Baby Manta Ray? I would assume the size could be the same, with a baby manta. But I don't know. This was brought up on a recent trip to Komodo, and nobody could seem to answer the question.
Posted 17 August 2012 - 12:40 AM
The most reliable way to tell is the position of the mouths - in mantas it is at the front of the 'face', in mobulas it's underneath
Posted 17 August 2012 - 01:47 AM
http://www.mantatrust.org/ also helps a bit
Posted 17 August 2012 - 04:06 AM
The mouth is the main ID feature as shown above, Mobula have a mouth on the bottom of their head, Mantas have theirs at the front.
The cephalic lobes rolled up are a big give away to, Mobulas look like devil horns giving them their name 'devile ray'.
There are other features but these are the two main ones and easiest to spot.
Posted 31 August 2012 - 08:14 AM
It's a good question - even marine scientists often make errors. Manta rays are born at approximately 1.4 to 1.8 m 'wingspan' so they're of a similar size to most mobula species.
The other respondents have given you excellent information: manta rays of either species have much more pronounced cephalic fins than mobula rays, and mouth position is a definitive character if you get a good view.
An easy way to tell them apart in the field is also to just look for spots on the underside. Manta rays will always have spots/blotches/defined markings between the gills or on the stomach, whereas mobula rays don't. Manta rays, excepting the black (melanistic) colour form, also have fairly well-defined white/grey shoulder markings which are rarely present in mobula. Also, manta rays (while they may feed in close proximity to one another) don't school to the same extent as mobula rays, so if you see a bunch of them swimming together then that is also a useful pointer.
Hope that helps!