Galapagos Species Database
The Galapagos Species Database shares the information about the species from our Natural History Collections.
Hydrolagus alphus
Whitespot Ghostshark
Assigned to the genus Hydrolagus based upon the absence of an anal fin. Hydrolagus alphus is distinguished by being medium in size (average PCL 321 mm) and uniform dark brown in color with a distinct white spot (4%-6% BDL) on the lateral side above the pectoral fins. Paired fins with bluish hue and white margins. The dorsal spine longer than triangular shaped first dorsal fin and extends beyond the origin of the second dorsal fin when depressed. Eyes large (40.8–44.5% HDL) and pectoral fins reaching to or beyond insertion of pelvic fins when depressed. Pelvic claspers small, not extending beyond distal edge of pelvic fin, and divided distally for one half their length with slender fleshy denticulate tips. The base of second dorsal fin is long, deeply depressed and light colored in the center, anterior and posterior regions dark, considerably greater in height than the white middle region (Ref. 57721).
Tropical (600 - 900 m) Benthopelagic
Domain
Eukaryota
Kingdom
Animalia
Phylum
Chordata
Class
Holocephali
Order
Chimaeriformes
Family
Chimaeridae
Genus
Hydrolagus
Species
alphus
Taxon category: Accepted
Origin: Endemic
- Appeltans, W. Bouchet, P., Boxshall, G.A., Fauchald, K., Gordon, D.P., Hoeksema, B.W., Poore, G.C.B., van Soest, R.W.M., Stöhr, S., Walter, T.C., Costello, M.J. (eds.) (2010) World Register of Marine Species (WoRMS). Available online at http://www.marinespecies.org.
- Froese, R. Pauly, D. (eds.) (2010) FishBase. World Wide Web electronic publication. www.fishbase.org
- McCosker, J.E. Rosenblatt, R.H. (2010) The fishes of the Galápagos Archipelago: an update. Proc. Calif. Acad. Sc., Ser. 4, vol. 61, Suppl. II, no. 11: 167-195.
- Quaranta, K. L. Didier, D. A., Long, D. J., & Ebert, D. A. (2006) A new species of chimaeroid, Hydrolagus alphus sp. nov. (Chimaeriformes: Chimaeridae) from the Galapagos Islands. Zootaxa, 1377, 33–45.
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This page should be cited as follows:
"Galapagos Species Database, Hydrolagus alphus", dataZone. Charles Darwin Foundation, https://datazone.darwinfoundation.org/en/checklist/?species=12750. Accessed 4 November 2026.