Aetobatus laticeps

Aetobatus laticeps is an eagle ray of the family Aetobatidae, described by Gill in 1865 ^[1]. In Peru it is called «raya bruja» ^[2]. Its back is bluish black covered in white spots and its belly is almost entirely white ^[3]. On the IUCN Red List it is listed as Vulnerable ^[4].

It is recognised by its bluish-black back with many white spots, its mostly white belly and a fleshy lobe with a parabolic outline in front of the head; the pectoral fins meet the head at eye level and stay separate from that lobe, and the large spiracles can be seen from above ^[3]. It usually measures under 130 cm in disc width, and reaches up to 230 cm ^[3].

Rays of the genus Aetobatus make up a family of their own, Aetobatidae, apart from the true eagle rays of the family Myliobatidae ^[5]. What sets them apart is that the pectorals reach the head at eye level, the flap between the nostrils has a deep notch, the rear tip of the pectorals is rounded, the spiracles can be seen from above and the dorsal fin ends in a free tip ^[5].

For a long time these rays of the American Pacific were included in Aetobatus narinari, then considered a single species found worldwide. A 2009 genetic study found that eastern Pacific specimens formed a lineage of their own, separated by the Isthmus of Panama from the central Atlantic lineage, and at the time proposed treating them as subspecies ^[6]. Later work restricted Aetobatus narinari to the continental western Atlantic ^[7], and an analysis of 72 individuals from 4 countries concluded that the spotted eagle rays of the continental coast of the eastern tropical Pacific belong to a single species, Aetobatus laticeps ^[8].

Similar species

• Myliobatis longirostris: It belongs to the family Myliobatidae, whose pectorals meet the head below eye level, with spiracles on the sides of the head that cannot be seen from above and a nearly straight flap between the nostrils ^[5].

It lives in the eastern Pacific, from the Gulf of California to Peru, the Galápagos Islands included ^[3]. A 2026 genetic study describes its range in the eastern tropical Pacific, from the Gulf of California to the Gulf of Guayaquil ^[8].

That same study gathered 87 samples from Mexico, Costa Rica, Ecuador and Peru, 22 of them Peruvian, and distinguished 3 populations: Costa Rica, Mexico, and Ecuador together with Peru, which the authors treat as a single freely interbreeding unit ^[8]. According to the authors, rays of the genus are benthopelagic mesopredators that hunt mostly for crustaceans and molluscs in shallow coastal areas ^[8].

It is found from inshore bays and estuaries out to offshore waters, and one may see a single ray or a big school ^[3]. At Los Arcos, in Banderas Bay (Mexico), it was studied around rocky-reef islets with patches of sand, at spots 3 to 12 m deep ^[9]. In the Mar Tropical de Grau National Reserve, the management plan counts it among the species of the rocky reefs ^[2].

Rays of the genus Aetobatus are described as ovoviviparous, with relatively long gestations and small litters, and give birth in protected coastal habitats ^[8]. The size at birth and the size at maturity of this species are poorly known ^[3].

At Los Arcos, the rays observed between 2015 and 2017 measured 50 to 130 cm in disc width, with a mean of 88.83 cm ^[9]. The authors took 90 cm as the threshold of adulthood, based on earlier observations of size at maturity and on 16 pregnant females of at least that size seen during and after the study, and recorded courtship or mating in only 0.68 % of the activities noted ^[9].

In 64 free dives made at Los Arcos between December 2015 and July 2017, 181 sightings were counted, 114 of adults and 67 of juveniles, and both juveniles and adults showed gregarious behaviour ^[9]. They were nearly always on the move (87.07 % of activity records); 10.88 % were searching for food in the sand or among rocks, and 1.36 % were being cleaned by fishes that remove parasites and dead skin ^[9].

Encounters were most frequent in April and May and fell to zero in the warmest months, with about 30 °C at the surface, and in the coldest, with about 23 °C; the highest number of encounters came between 25 and 27 °C ^[9]. The authors consider it likely that the rays frequent Los Arcos because prey is plentiful, and note that the site has a great diversity and abundance of molluscs ^[9]. Its diet is mostly bivalves, with shrimps, polychaete worms and other fishes as a complement ^[3].

Its global category on the IUCN Red List is Vulnerable ^[4]. The 2026 genetic study recommends reassessing its status, at least in Mexico ^[8].

In Peru, the management plan of the Mar Tropical de Grau National Reserve includes it among the rocky-reef species considered highly threatened by bad practices in spearfishing and by other fishing gear ^[2]. The plan names it among the large rays ^[2], and for large coastal rays it points to catches with bottom gillnets, spearguns and handlines, plus incidental catches by purse seiners and bottom trawlers operating illegally, with populations that have been significantly reduced ^[2]. Within the reserve it may not be taken in the Arrecifes de Punta Sal sector ^[2] nor in the Cabo Blanco – El Ñuro sector ^[2].

In Banderas Bay a ray of this species was recorded with fresh propeller wounds, and the authors call for regulating boat traffic and speed ^[9].

The 22 Peruvian samples of the 2026 genetic study were obtained from fishers who had caught it as bycatch ^[8]. In January 2017, a whole fresh ray on sale at the Cancas landing site, Tumbes, was identified as this species by DNA barcoding ^[10].

In Mexico, the species is important for recreational tourism at Los Arcos, an islet group visited by divers, kayakers and boat tours ^[9].

The 2026 management plan cites it in the Arrecifes de Punta Sal ^[2] and Cabo Blanco – El Ñuro sectors of the Mar Tropical de Grau National Reserve ^[2]. In January 2017 a specimen landed at Cancas, Tumbes, was recorded ^[10].