Longfin Batfish, Platax teira
Longfin Batfish, Platax teira, Juvenile. Underwater photograph taken in Zihuantanejo Bay, Guerrero, March 2026. Photograph and identification courtesy of Ron Woheau and John Orrell, Zihuantanejo, for this important find in coastal waters of Zihuantanejo.
The Longfin Batfish, Platax teira, is a member of the Spadefish and Batfish or Ephippidae Family, that is known as the Longfin Spadefish, the Round-faced Batfish, and the Teira Batfish and in Mexico as pollera aletona. Globally, there are five species in the Platax Genus, with only this species being found in Mexican waters of the Pacific Ocean.
The Longfin Batfish can be found in large schools with large adults found within mangroves in protected reefs and in sheltered bays in shallow coastal environments and over deeper offshore reefs at depths up to 70 m (230 feet). The juveniles are brown in color and shelter in small groups amongst floating debris including Sargassum rafts. As they mature they develop pelvic fins and the front soft rays of the anal and dorsal fins become highly elongated, extending to around the posterior of the base of the anal fin dramatically changing the overall body shape. They also become more pelagic and form sizable schools with aging. They reach a maximum of 70 cm (2 feet 4 inches) in length. They are omnivores that feed on algae, benthic invertebrates and zooplankton.
The Longfin Batfish have a strongly compressed, disc-shaped, large, rounded body that is silvery to grayish-brown fish with a characteristic dark blotch below the pectoral fin, a dark vertical bar through the eye, a second bar through the pectoral fin, and yellow to blackish pelvic fins with black margins posteriorly. They have the ability to change color from silvery white with no bands to brown with dark banding and then back to silver again.
Their head with a smooth convex upper profile and is short with a blunt snout and with a bony hump on top. Their mouth opens at the front and has bands of slender, flattened, tricuspid teeth, and a few vomer teeth. Adults also have a low hump on the nape. The gill cover has a smooth margin. Larger juveniles have the pelvic fins and anterior soft rays of the dorsal and anal fins very elongated reaching the rear of the anal-fin base. Their anal fin has 3 spines and 22 to 28 rays; their caudal fin is truncated; their dorsal fin is continuous with the first dorsal fin having 5 or 6 spines, their second dorsal fin having 28 to 37 rays; their pectoral fins are short with 16 to 18 rays; and their pelvic fins originate before the pectoral fins. They have 8 to 10 lower gill rakers. They are covered with small scales and have a complete lateral line.
They are a common widely-distributed Indo-West Pacific species that have been recently discovered as a newly introduced invasive species in New Zealand and the Mediterranean. The Longfin Batfish was initially sited in Mexican waters within the Cabo Pulmo National Park, Baja California Sur, in December 2023. Additional sightings have been made in 2025 in Manzanillo, Colima, within the Marietas Islands National Park and Cruz de Huanacaxtle in Nayarit and in Huatulco, Oaxaca. The fish photographed documents the first sighting of the species within coastal waters of Guerrero. The arrival of this species into coastal Mexican waters is attributed to warm water periods associated with strong El Niño–Southern Oscillation (ENSO) events with the fish being transported by Kelvin waves from the central Pacific, carried by floating debris or algal rafts. Alternatively, the species may have reached the eastern Pacific through the transport of adults or larvae by the North Equatorial Countercurrent, which is considered as unlikely.
The adult Longfin Batfish can be confused with the Pacific Spadefish, Chaetodipterus zonatus (large pelvic fins, six bars on the sides) and the, Panama Spadefish, Parapsettus panamensis (9 spines first dorsal fin with 9 spines, well developed hump before and above the eyes).
From a conservation perspective the Longfin Batfish is currently considered to be of Least Concern with stable, widely distributed populations. They can be caught by hook and line but only retained by subsistence fishermen. The juveniles are utilized by the aquarium trade as an ornamental due to their striking shape, peaceful nature and social behavior. They grow rapidly to 61 cm (2 feet 0 inches) in captivity.