Species boundaries in the Himantura uarnak species complex (Myliobatiformes: Dasyatidae)

Abstract

Samples of the 'Himantura uarnak' species complex (H. leoparda, H. uarnak, H. undulata under their current definitions), mostly from the Coral Triangle, were analyzed using nuclear markers and mitochondrial DNA sequences. Genotypes at five intron loci showed four reproductively isolated clusters of individuals. The COI sequences showed four major mitochondrial lineages, each diagnostic of a cluster as defined by nuclear markers. No mitochondrial introgression was detected. The average Kimura-2 parameter nucleotide distance separating clades was 0.061-0.120 (net: 0.055-0.114), while the distance separating individuals within a clade was 0.002-0.008. Additional, partial cytochrome-b gene sequences were used to link these samples with previously published sequences of reference specimens of the three nominal species. One of the clusters was identified as H. undulata and another one, as H. uarnak, while two cryptic species were uncovered within the recently-described H. leoparda, challenging the current morphology-based taxonomy of species within the H. uarnak species complex.

First record of the honeycomb stingray Himantura leoparda (Manjaji-Matsumoto & Last, 2008) (Myliobatoidei: Dasyatidae) in the Mediterranean Sea, confirmed by DNA barcoding

“…When the results of Arlyza et al. () and the present study were combined, it was clearly seen that the Mediterranean Sea samples were clustered as in Clade IV Arlyza et al. ().…”

“…During the analysis only two base pair (bp) differences were observed between the samples in the present study and two previously‐studied H. leoparda samples from South Africa [Arlyza et al. (), H27, see Figure ], and five bp differences observed for three H1samples from India (KF899500, KF899501, and KF899502). On the other hand, mutation numbers between the present study and previously studied H. leoparda specimens from Indonesia, Malaysia and Tanzania were observed as being above 10 bp (see Figure ).…”

“…The DNA barcode of the present study sample produced a 99% match with the H. leoparda species of Arlyza et al. () from South Africa.…”

“…(), Arlyza et al. (), and Lim, Lim, Chong, and Loh () and in the sequences of four unpublished Indian H. leoparda samples (KF899500, KF899501, KF899502, and KF899353) from Indonesia, India (Bineesh), Tanzania (Zanzibar), Malaysia (Kean‐Chong) and South Africa (KwaZulu‐Natal, Cape Videl) were used to build the network (see Table S1). During the analysis only two base pair (bp) differences were observed between the samples in the present study and two previously‐studied H. leoparda samples from South Africa [Arlyza et al.…”

“…Samples of the ‘ Himantura uarnak ’ species complex ( H. leoparda, H. uarnak, H. undulata ) were analyzed using nuclear markers and mitochondrial DNA sequences by Arlyza et al. (). According to their study, the COI sequences showed four major mitochondrial lineages and both Clades I and IV clustered with sequences of reference H. leoparda specimens.…”