Hortle's whipray (Pateobatis hortlei)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Elasmobranchii · Order: Myliobatiformes · Family: Dasyatidae · Genus: Pateobatis.

Accepted name: Pateobatis hortlei · Authority: (Last, Manjaji-Matsumoto & Kailola, 2006) · Taxonomic status: accepted · AphiaID: 1043417.

Synonyms and superseded combinations recorded for this taxon: Himantura hortlei Last, Manjaji-Matsumoto & Kailola, 2006.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=1043417 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Pateobatis hortlei. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 70.69999694824219 cm · Depth range: 2–7 m · Habitat zone: demersal · Body shape: other · Vulnerability index: 90 of 100 · Aquarium trade: never/rarely.

FishBase notes: Demersal inshore; commonly found over shallow intertidal mud flats and in estuaries in only several metres depth. Viviparous, with histotrophy. Presumably feeds on crustaceans, molluscs and small fishes. Caught regularly, but usually avoided, by beach seine fisheries operating in intertidal habitats. Possibly adversely affected by mangrove loss. Utilized for its meat, and possibly also for its skin and cartilage. (Ref.58048).

Source: FishBase species summary (SpecCode 63342) — https://www.fishbase.se/summary/Pateobatis-hortlei.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

82 georeferenced occurrence records for Pateobatis hortlei are published through GBIF from 3 countries or marine areas. The map above plots 5 distinct locations from a sample of 82 records, omitting 3 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Papua New Guinea (43); Indonesia (33); Australia (6).

Source: GBIF Occurrence Search (taxonKey 9595067) — https://www.gbif.org/occurrence/search?taxon_key=9595067&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=1043417 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Pateobatis hortlei (Last, Manjaji-Matsumoto & Kailola, 2006) as Near Threatened (code NT). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 161598) — https://www.iucnredlist.org/species/161598/0; GBIF IUCN Red List category endpoint (taxonKey 9595067) — https://api.gbif.org/v1/species/9595067/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

The Hortle's whipray was named after Kent Hortle, a biological consultant at the Freeport mine in the Indonesian province of Papua, who provided the first photographs and fresh specimens of the ray to biologists. The species was formally described by Peter Last, Mabel Manjaji-Matsumoto, and Patricia Kailola in a 2006 issue of the scientific journal Zootaxa. An adult male 71 cm across, collected from the estuary of the Minajerwi River, was designated as the type specimen. This ray belongs to the 'uarnacoides' species complex, along with H. chaophraya, H. granulata, H. lobistoma, H. pastinacoides, and H. uarnacoides.

The Hortle's whipray is found only off southern Papua province, and perhaps also neighboring Papua New Guinea. It inhabits brackish water estuaries and intertidal mud flats, in water no deeper than 10 m.

The pectoral fin disc of the Hortle's whipray is heart-shaped and slightly longer than wide; the anterior margins are concave and converge on a highly elongated, narrowly triangular snout. The eyes are tiny and spaced wide apart, and immediately followed by large, teardrop-shaped spiracles. There is a broad, roughly rectangular curtain of skin between the nostrils with a finely fringed posterior margin. The mouth is strongly bow-shaped and does not contain papillae (nipple-shaped structures). The small, blunt teeth are set closely with a quincunx pattern, and stained orange to brown in adults. There are 21–25 upper and 24–28 lower tooth rows. The five pairs of gill slits are distinctively S-shaped.

The pelvic fins are short and broad. The very thin tail measures 2.6–3.4 times as long as the body, and lacks fin folds. One or two stinging tail spines are placed on the upper surface of the tail, about one-third of a disc width back from the tail base. A wide band of flattened dermal denticles, composed of larger heart-shaped denticles and smaller variably-shaped interstitial denticles, runs along the dorsal surface of the disc from before the eyes to the tail. Small, sharp denticles are scattered over the snout and concentrated at the tip. The tail past the sting is uniformly covered by denticles. The lateral line network is well-developed both over and beneath the disc. Smaller rays are plain greenish gray above, while larger rays are yellowish brown; the tail is uniformly brown and lighter in front of the sting. The underside is distinctively bright yellow, with a thin dark border around the disc margin and sometimes darker blotches around the nostrils, mouth, and gill slits. The largest known male is 71 cm across, and the largest female 65 cm across.

Little is known of the natural history of the Hortle's whipray. It is presumed to be a predator of crustaceans, molluscs, and small fishes. Reproduction is aplacental viviparous, with the females supplying their developing embryos with histotroph ("uterine milk"); the young are born at under 20 cm across.

Beach seine fishers targeting prawns try to avoid the Hortle's whipray, but still take it regularly as bycatch. The meat, and possibly also the skin and cartilage, is utilized. This ray is also threatened by habitat degradation, from the large-scale destruction of mangroves, intensive mining activity, and river pollution. While the Hortle's whipray remains common within its small range, the International Union for Conservation of Nature (IUCN) believes these factors have led to a population decline, and has assessed it as Near Threatened.

Source: Wikipedia: Hortle's whipray — https://en.wikipedia.org/wiki/Hortle%27s_whipray (CC BY-SA 4.0). Accessed 2026-09-23.