Myliobatidae

Elasmobranch, Its Implications For Global, Parasitology, Diversity And, Naylor, G. J. P., Sc, Caira, J. N., Ct, Jensen, K., Ks, Rosana, K. A. M., Fl, White, W. T., Csiro, Tas, Last, P. R., Csiro & Tas, 2012, A Dna Sequence-Based Approach To The Identification Of Shark And Ray Species And Its Implications For Global Elasmobranch Diversity And Parasitology, Bulletin of the American Museum of Natural History 2012 (367), pp. 1-262 : 82-85

Myliobatidae (eagle rays)

Pteromylaeus bovinus (duckbill ray) ( fig. 61)

A single specimen of this species was included in the analysis. This specimen was collected from Senegal and thus represents a northeastern element of the distribution of this species, which occurs from Portugal, throughout the western coast of Africa, around the cape and as far north as Mozambique. It clustered away from other myliobatids and along with, but outside all of the species of Rhinoptera and Mobula .

Myliobatis californica (bat ray) ( fig. 62)

The 18 specimens of this species were collected from throughout the Gulf of California and thus represent the southern parts of the distribution of this species, which has been reported to occur from Oregon to Baja, with a rare report from the Galapagos Islands ( Grove and Lavenberg, 1997). One of these specimens was deposited in the Texas Cooperative Wildlife Collection (GN5203 5 TCWC 7564.03). The analysis yielded a single cluster with a range in pairwise differences among the 18 specimens of 0–12, with an average of 5.6.

Myliobatis aquila (common eagle ray) ( fig. 62)

The seven specimens of this eastern Atlantic-dwelling species were all collected from South Africa. The range of pairwise differences among specimens in this cluster was 0– 2, with an average of 0.7.

Myliobatis tobijei (kite ray) ( fig. 62)

The analysis included three specimens of this species, which occurs from Japan to Indonesia, one of which came from Taiwan and two from the Philippines. The specimens from the Philippines (GN4384 5 JPAG 130 and GN4357 5 JPAG 147) were treated by Compagno et al. (2005b) as M. cf. tobijei . However, given that the range in pairwise differences among specimens from both localities was only 1–7, with an average of 4.7, we have used the designation M. tobijei for all three specimens in this cluster. These specimens grouped most closely with those of M. aquila . The average of the pairwise differences among specimens in these two clusters was 48.9.

Myliobatis longirostris (longnose eagle ray) ( fig. 62)

Sixteen specimens of this Gulf of California endemic were included in the analysis, which yielded a single cluster. Five of these specimens were deposited in the Texas Cooperative Wildlife Collection (GN5200 5 TCWC 7564.04, GN5201 5 TCWC 7564.06, GN5241 5 TCWC 7589.04, GN5269 5 TCWC 7587.01, and GN1570 5 IBUNAM PE9517). Although many of the specimens were identical in sequence, the range in pairwise differences among all specimens in this cluster was 0–11, with an average of 2.5.

Myliobatis freminvillei (bullnose ray) ( fig. 62)

The two specimens identified as M. freminvillei included in the analysis differed by a single base. They were both collected from the western North Atlantic and thus represent more northern elements of the amphitropical distribution of this species, which has been reported as far south as Argentina. This species grouped most closely with M. longirostris ; the average of the pairwise differences among specimens of these two species was 52.8.

Myliobatis australis (southern eagle ray) ( fig. 62)

The analysis included four specimens of this species, all collected from the Tasman Sea in Australia. They thus represent a more eastern element of the distribution of this species, which has been reported from southern Australia and possibly New Zealand ( Last and Stevens, 2009). The range in pairwise differences among these specimens was 0–4, with an average of pairwise difference of two bases.

Aetomylaeus species

The analysis included specimens of six nominal species of Aetomylaeus . A haplotype map for phenotype ( fig. 100A) and also one for geography ( fig. 100B) was generated for the five most similar of these species (i.e.,all but A. vespertilio ). The phenotype map supports recognition of three distinct species in the A. nichofii complex because it shows no overlap in haplotypes among specimens of the different species and also illustrates the substantial amount of divergence between the sympatric A. nichofii and A. maculatus . However, additional specimens from the Persian Gulf would help to confirm the distinction between A. cf. nichofii 1 and A. nichofii . The haplotype map for geography illustrates the allopatric nature of these three species.

Aetomylaeus nichofii (banded eagle ray) complex

( fig. 62)

Eighteen specimens that were generally consistent with the color morph of Aetomylaeus nichofii were included in the analysis. The majority of these came from a diversity of localities around the island of Borneo, but they also included one specimen from the Persian Gulf and two from the Arafura Sea off northern Australia. The analysis yielded a group consisting of these 18 specimens. However, the 15 specimens from Borneo represented a cluster within this group; five of these specimens were vouchered (GN4264 5 CAS 229046, GN2968 5 ANFC H 6209-01, GN2969 5 ANFC H 6209-02,GN3444 5 IPPSBO180, and GN3696 5 IPPS BO485). The range of pairwise differences among the 15 specimens in the Borneo cluster was 0–10, with an average of 3.3. The Persian Gulf and Arafura Sea specimens grouped along with but outside the Borneo specimens. The two specimens from the Arafura Sea differed by one base. The average of the pairwise difference between the specimens from Borneo and the specimen from the Persian Gulf was 17.7, and between the specimens from Borneo and those from the Arafura Sea was 74. Furthermore, pairwise difference between the specimens from the Persian Gulf and Arafura Sea was 72. These results suggest that our sample may include three distinct taxa. Until this issue can be addressed in more detail, we have provisionally referred to the specimens in the Borneo cluster as Aetomylaeus nichofii as the type locality for this species is Indonesia. The specimen from the Persian Gulf has been referred to as Aetomylaeus cf. nichofii 1, and the specimen from the Arafura Sea referred to as Aetomylaeus cf. nichofii 2. A taxonomic revision of this complex is currently being undertaken by P.L. and W.W.

Aetomylaeus maculatus (mottled eagle ray) ( fig. 62)

In total, 10 specimens consistent with the color pattern of A. maculatus were included in the analysis. The analysis yielded a single cluster, but with evidence of two subclusters; one comprised primarily of specimens from Malaysian Borneo and one of specimens from Indonesian Borneo. Three of the samples from Borneo come from museum specimens (GN2993 5 ANFC H 6220-01 , GN3423 5 ANFC H 6123-04 and H 6122-02, and GN3442 5 ANFC H 6219-02 ). The range in pairwise differences among all 10 specimens in the cluster was 0–17, with an average of 8.3. The range of pairwise differences among specimens within the Malaysian subcluster was 0–5 ; the three specimens in the Indonesian subcluster were identical in sequence. The average of the pairwise differences among specimens in the two subclusters was 15.2. However, in the absence of consistent morphological or geographic differences, we have made no formal distinction between the two subclusters. It should be noted that our specimens represent only a small portion of the distribution of this species, which has been reported from throughout much of the Indo-West Pacific.

Aetomylaeus milvus (ocellate eagle ray) ( fig. 62)

Two specimens collected from the Persian Gulf were included in the analysis. These specimens were identical in sequence to one another. They grouped most closely with specimens of Aetomylaeus maculatus . However, the average of the pairwise differences between specimens of these two species was 95.2. This result supports the validity of this species, which has been questioned by some previous authors (e.g., Compagno, 1999). Aetomylaeus vespertilio (ornate eagle ray) ( fig. 62)

The five specimens of this species included here were collected from the Arafura Sea and Gulf of Carpentaria, off northern Australia, and from the Philippines. These specimens represent eastern elements of the distribution of this Indo-West Pacific species, which has been reported from as far west as the Mozambique Channel. The Philippine specimen (GN4344 5 JPAG 324) was treated as A. vespertilio by Compagno et al. (2005b). The analysis yielded a single cluster of these specimens, which had a range of pairwise differences of 0–5, with an average of pairwise differences of 2.8 bases.

Aetobatus species

Until recently, a great deal of confusion has existed with respect to the identity of the various color morphs of ‘‘spotted eagle rays.’’ Several authors (e.g., Last and Stevens, 2009; Richards et al., 2009) have noted that the genus may include more species than currently recognized. The taxonomy of the spotted eagle ray group was recently partially revised by White et al. (2010c), who resurrected a number of existing names for the various color morphs that appear to represent distinct valid taxa. The treatment of this genus here follows the taxonomy proposed by White et al. (2010c). The haplotype maps for our Aetobatus specimens provide support for the recognition of all seven of the nominal species treated below. Specimens of these species share no haplotypes ( fig. 101A). Furthermore, the majority of these species exhibit relatively restricted and allopatric geographic distributions ( fig. 101B).

Aetobatus ocellatus (whitespotted eagle ray) com-

plex ( fig. 63)

The analysis yielded a cluster comprised of 34 specimens from throughout the Indo-West Pacific (i.e., Malaysian and Indonesian Borneo as well as from Taiwan, Thailand, Vietnam, Singapore, the Philippines, and northern Australia). The range of pairwise differences among specimens in this cluster was 0–16, with an average of 5.8. These specimens are morphologically consistent with previous accounts of A. ocellatus (e.g., see White et al., 2010c), the type locality of which is Java in Indonesia. One of the specimens from the Philippines (GN4364 5 JPAG 314) was treated by Compagno et al. (2005b) as Aetobatus cf. narinari . Two of the specimens from Borneo were also deposited (GN3550 5 IPMB 38.01.08 and GN3513 5 IPPS BO296).

However, three additional specimens, one from the Mozambique Channel and two from off Qatar in the Persian Gulf, clustered along with but outside these 34 specimens. Specimens from the Mozambique Channel and Qatar are genetically different from one another, and also from those from the Indo-West Pacific. The average of the pairwise differences between the specimen from the Mozambique Channel ( A. cf. ocellatus 1) and those from the Indo-West Pacific ( A. ocellatus ) was 20.2; the average of pairwise differences between the specimen from the Mozambique Channel and the two from Qatar ( A. cf. ocellatus 2) was 29. The average of the pairwise differences between the specimens from Qatar ( A. cf. ocellatus 2) and the Indo-West Pacific ( A. ocellatus ) was 26.8. Unfortunately, photographs are unavailable for any of the three specimens from the Mozambique Channel and Qatar. Nonetheless, they have been referred to here as Aetobatus cf. ocellatus 1 and Aetobatus cf. ocellatus 2, respectively, based on their genetic differences. The two specimens of A. cf. ocellatus 2 differed by two bases.

Aetobatus narinari (spotted eagle ray) ( fig. 63)

Fourteen specimens identified as this species were included in the analysis. These specimens came from the Florida Keys and Gulf of Mexico, as well as from Puerto Rico. Three of the specimens from the Florida Keys came from vouchers (GN5675 and GN5676 5 AMNH 251703 and GN5678 5 AMNH 251704). The analysis yielded essentially a single cluster with a range in pairwise differences of 0–18, and an average of 4.4. However, one of the specimens from Puerto Rico (GN2118) differed conspicuously from the other 13 specimens in the cluster. The average of the pairwise differences between this specimen and the other 13 was 14.6. The specimens in this cluster are morphologically generally consistent with A. narinari , the type locality of which is St. Barthélemy in the Caribbean Sea and Brazil. We have included the more divergent Puerto Rican specimen under this name, but note that it differs, for example, from the other Puerto Rican specimen (GN2119), in that many more of its white spots are ocellate, rather than solid.

Aetobatus laticeps (Pacific whitespotted eagle ray)

( fig. 63)

The analysis also yielded a cluster comprised of four specimens collected from Loreto in the Gulf of California. These specimens are generally consistent with Aetobatus laticeps , described from California by Gill (1867). The range of pairwise differences among these specimens was 0–2, with an average of 1. These specimens clustered most closely with those of A. narinari ; the average of the pairwise differences between specimens of these two species was 14.9.

Aetobatus sp. ( fig. 63)

Nine specimens from Vietnam, that differed conspicuously morphologically from the five other species of eagle rays included here, were also found to comprise a cluster that was genetically distinct from the five other species. The range of pairwise differences among specimens in this cluster was 0–2, with an average of 0.4. Unlike other species in the genus, these specimens lacked white spots from the dorsal surface and exhibited a relatively short head. These specimens likely represent an undescribed species. Two of these specimens were deposited in the Vietnam Natural Museum of Nature (GN7014 5 VN-z-v.000394 and GN7050 5 VN-z-v.000309).

Aetobatus flagellum (longheaded eagle ray) ( fig. 63)

The two specimens of this species included in the analysis were collected from Indonesian Borneo and Maharastra, India, and they differed from one another by 11 bases. These specimens are consistent with A. flagellum , whose type locality is the coast of Coramandel off India. They clustered most closely with Aetobatus sp. from Vietnam. The average of the pairwise differences between A. flagellum and those of Aetobatus sp. was 93.7.