| Common names: whalesucker (English), rémora (Espanol) |
Remora australis (Bennett, 1840)
Body elongate, robust; dorsal and anal bases < 2x head length; head disc very long (almost ½ body length), reaches beyond pectorals, with 24-28 plates; gill rakers 17-20, 13-19 lower rakers; pectoral short, blunt, 21-24 rays; dorsal and anal bases similar length, a little longer than head; dorsal 22-26 rays, anal 21-26 rays; tail slightly concave (forked in juvenile); pelvics long, pointed, broadly attached to belly.
Dark blue to slate grey, dorsal and anal fins with narrow white margin.
Size: 76 cm.
Habitat: oceanic, hosts are whales.
Depth: 0-200 m?
A circumtropical species, found throughout our region except for the upper Gulf of California.
Global Endemism: All species, TEP non-endemic, Circumtropical ( Indian + Pacific + Atlantic Oceans), "Transpacific" (East + Central &/or West Pacific), East Pacific + Atlantic (East +/or West), Transisthmian (East Pacific + Atlantic of Central America), East Pacific + all Atlantic (East+West)
Regional Endemism: All species, Eastern Pacific non-endemic, Tropical Eastern Pacific (TEP) non-endemic, Continent + Island (s), Continent, Island (s)
Climate Zone: North Temperate (Californian Province &/or Northern Gulf of California), Northern Subtropical (Cortez Province + Sinaloan Gap), Northern Tropical (Mexican Province to Nicaragua + Revillagigedos), Equatorial (Costa Rica to Ecuador + Galapagos, Clipperton, Cocos, Malpelo), South Temperate (Peruvian Province )
Regularity: Regularly occurring
Type of Residency: Year-round
Inshore/Offshore: Offshore Only, Offshore
Water Column Position: Near Surface, Mid Water, Water column only
Habitat: Water column, Large fishes (billfishes, rays, sharks, etc), turtles & whales
FishBase Habitat: Pelagic
Habitat Type: Marine
Water temperature and chemistry ranges based on 1 sample.
Depth range (m): 235 - 235
Temperature range (°C): 14.230 - 14.230
Nitrate (umol/L): 16.740 - 16.740
Salinity (PPS): 35.746 - 35.746
Oxygen (ml/l): 3.350 - 3.350
Phosphate (umol/l): 1.218 - 1.218
Silicate (umol/l): 8.021 - 8.021
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Diet: Pelagic crustacea, zooplankton, pelagic fish larvae, ectoparasites, bony fishes
Life History and Behavior
Molecular Biology and Genetics
Barcode data: Remora australis
Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen.
Other sequences that do not yet meet barcode criteria may also be available.
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Download FASTA File
Statistics of barcoding coverage: Remora australis
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
CITES: Not listed
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
NatureServe Conservation Status
Rounded Global Status Rank: GNR - Not Yet Ranked
The whalesucker, Remora australis, is a species of remora in the family Echeneidae, so named because it attaches itself exclusively to cetaceans. It is found worldwide in tropical and warm waters; in the Gulf of Mexico and western Atlantic Ocean, it occurs from Texas to Brazil, and in the eastern Pacific Ocean, it occurs from Vancouver Island to Chile. It is the rarest member of the remora family, though this may reflect more the uncommon collection of cetaceans in the wild rather than the whalesucker's actual abundance.
The adhesive disk atop the head of the whalesucker is the largest amongst the remoras, bearing 25-28 lamellae and measuring 47-59% of the standard length. The head itself measures 26-28% of the standard length. The dorsal fin rays number 23-26, the anal fin rays 24-26, and the pectoral fin rays 22-24. The jaws contain numerous large, stout canine teeth; the palatine and lingual patches are absent, and there are 17-20 gill rakers. The coloration is uniform brown, dark brown, or greyish-brown on the head, trunk, and fins. Whalesuckers observed off Fernando de Noronha ranged from light grey to slate grey, with lighter fin margins. The smaller individuals are barred or blotched, while individuals over 35 cm long have yellowish fins. This species can reach 76 cm (30 in) in total length.
The most common host of the whalesucker appears to be the blue whale. Chitinous material indicative of parasitic copepods or amphipods have been found in the stomachs of whalesuckers, suggesting a mutualistic relationship with their hosts. Off Fernando de Noronha, whalesuckers down to small (4 to 9 cm (1.6 to 3.5 in)) juveniles are associated with spinner dolphins, and are likely recruited year-round from flotsam. The whalesuckers, no more than three to a host, usually attach to the flanks or belly of the dolphin, which may serve to minimize drag and facilitate feeding. When approached, they, especially small individuals, will shift to the opposite side of the host for protection. Whalesuckers impose a hydrodynamic cost to their host, their adhesive disks can abrade the skin, and they sometimes attach to inconvenient locations, such as near the blowhole or the genitals. The spinning behavior of dolphins, sharks, and other remora hosts has been proposed as a means of dislodging them. The whalesuckers feed on parasites and sloughed-off skin, and also forage on feces and vomit from the dolphins.
- Froese, Rainer and Pauly, Daniel, eds. (2013). "Remora australis" in FishBase. April 2013 version.
- O'Toole, B (Apr 2002). "Phylogeny of the species of the superfamily Echeneoidea (Perciformes: Carangoidei: Echeneidae, Rachycentridae, and Coryphaenidae), with an interpretation of echeneid hitchhiking behaviour". Canadian Journal of Zoology 80 (4): 596–823. doi:10.1139/z02-031.
- Lachner, E.A. (1986). "Echeneididae". In Whitehead, P.J.P, et al.. Fishes of the North-eastern Atlantic and the Mediterranean. Paris: United Nations Educational, Scientific and Cultural Organization. ISBN 92-3-002309-4.
- Silva-Jr., J. M. and Sazima, I. (2006). Whalesuckers on spinner dolphins: an underwater view. JMBA2-Biodiversity Records: 1-6. 
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