The mtDNA CO1 sequences obtained from five M. alfredi (Africa)
and two M. birostris (Africa and Indonesia) were identical. CO1 sequences
from four Japanese M. alfredi were identical, and differed
from African and Indonesian specimens by 2 bp. As CO1 did not
distinguish the two species we terminated further sequencing for
this region and obtained 681 bp of nDNA RAG1 sequence and
1188 bp of mtDNA ND5 sequence from all specimens (n = 89 Manta
specimens and n = 6 Mobula specimens). The number of haplotypes
were NRAG1 = 2 and NND5 = 5 for M. alfredi, and NRAG1 = 4 and
NND5 = 12 for M. birostris (Tables 1 and 2). No haplotypes were
shared between the two species. Haplotype (h) and nucleotide
(p) diversity for M. alfredi were hRAG1 = 0.08 ± 0.05, pRAG1 = 0.0001 ±
0.0002, hND5 = 0.75 ± 0.03, and pND5 = 0.0035 ± 0.0019. Values for
M. birostris were hRAG1 = 0.57 ± 0.04, pRAG1 < 0.0001, hND5 = 0.84 ±
0.05 and pND5 = 0.0019 ± 0.0012. Genetic differentiation between
the two species was significant in both markers: USTRAG1 = 0.97
(p < 0.001) and USTND5 = 0.53 (p < 0.001).
The two species were reciprocally monophyletic