Redescription of the bigeye chimaera, Hydrolagus macrophthalmus de Buen, 1959 (Chondrichthyes: Chimaeriformes), with a genetic characterization of the species
Hydrolagus macrophthalmus de Buen, 1959 is a little known chimaerid species from the southeastern Pacific Ocean. At the time of its description, it was the only chimaeroid species known from the region; however, there now are four other Hydrolagus species known from the area. Hydrolagus macrophthalmus is distinct from other species in the area based on the following characters: an undulated second dorsal fin with peaks on the anterior and posterior regions, a long curved first dorsal fin spine that extends past the origin of the second dorsal fin when laid flat, and uniform dark brown color with a light spot on middle of the second dorsal fin that extends onto the body below it. Genetic sequencing of the NADH2 gene was used to distinguish H. macrophthalmus from other known species in the region. This species is herein re-described and compared to four sympatric species: H. alphus, H. melanophasma, H. mccoskeri, and H. trolli. The redescription of this species will improve identification and aid in the taxonomic resolution of Southeastern Pacific Ocean chimaeras. A key to species of Hydrolagus in the Southeastern Pacific Ocean is provided.
KeywordsChimaeridae Hydrolagus Holotype Chile Identification NADH2
The authors would like to thank Dominique Didier (Millersville University) for general discussions related to this project, and James Lindholm (CSU Monterey Bay) and the students of the Pacific Shark Research Center including Paul Clerkin, Justin Cordova, Maddie Harris, Kelsey James, Melissa Nehmans, Amber Reichert, and Marty Schmidt who helped with data collection and/or manuscript review. Finally, Matthew Jew would like to extend the sincerest thanks to his parents Kathy and Fulton Jew for fostering a passion for science from a very young age.
This project was supported in part by the National Science Foundation (NSF) Collaborative Research: Jaws and Backbone: Chondrichthyan Phylogeny and a Spine for the Vertebrate Tree of Life (DEB 1132229). This project was funded by the Undergraduate Research Opportunities Center (UROC) at California State University, Monterey Bay.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed by the authors. Tissues were collected under the Institutional Animal Care and Use Committee (IACUC) Non-Living Tissue Protocol 2014D.
Sampling and field studies
All necessary permits for sampling and observational field studies have been obtained by the authors from the competent authorities and are mentioned in the Acknowledgements, if applicable.
- Barnett LAK, Didier DA, Long DJ, Ebert DA (2006) Hydrolagus mccoskeri sp. nov., a new species of chimaeroid fish from the Galápagos Islands (Holocephali: Chimaeraformes: Chimaeridae). Zootaxa 1328:27–38Google Scholar
- Chirichigno N (1968) Nuevos registros para la ictiofauna marina del Peru. Instituto del Mar del Peru Boletin 1(8):127pGoogle Scholar
- de Buen F (1959) Notas preliminaries sobre la fauna marina preabismal de Chile, con descripcion de una familia de rayas, dos generous y siete species nuevo. B Mus N Hist Nat 27(3):171–201Google Scholar
- Didier DA, Séret B (2002) Chimaeroid fishes of New Caledonia with description of a new species of Hydrolagus (Chondrichthyes, Holocephali). Cybium 26(3):225–233Google Scholar
- Ebert DA (2016) Deep-sea cartilaginous fishes of the southeastern Pacific Ocean: FAO species catalogue for fishery purposes, No. 10. FAO, Rome, p 241Google Scholar
- Ebert DA, Winton MV (2012) Chondrichthyans of high latitude seas. In: Carrier JC, Musick JA, Heithaus MR (eds) Biology of sharks and their relatives II. CRC Press, Boca Raton, pp 115–158Google Scholar
- Eschmeyer WN, Fricke R, van der Laan R (2014) Catalog of fishes: genera, species, references. http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. Accessed 05 Mar 2018
- Garman S (1901) Genera and families of the Chimaeroids. Proc New Engl Zool Club 2:75–77Google Scholar
- Gonzalez-Acosta AF, Castro-Aguirre JL, Didier DA, Velez-Marin R, Burnes-Romo LA (2010) Occurance of Hydrolagus macrophthalmus (Chondrichthyes: Holocephali: Chimaeridae) in the northeastern Pacific. Rev Mex Biodivers 81:197–201Google Scholar
- Hardy GS, Stehmann M (1990) A new deep-water ghost shark, Hydroalgus pallidus n. sp. (Holocephali, Chimaeridae), from the Eastern North Atlantic, and a redescription of Hydrolagus affinis (Brito Capello, 1867). Arch Fischereiwiss 40(3):229–248Google Scholar
- IUCN 2016. The IUCN Red List of Threatened Species. Version 2016-1. <http://www.iucnredlist.org>. Downloaded on 30 June 2016
- James, K.C., Ebert, D.A. (2011) Hydrolagus melanophasma. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 18 November 2017
- James KC, Ebert DA, Long DJ, Didier DA (2009) A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chondrichthyes: Chimaeraformes: Chimaeridae), from the eastern North Pacific. Zootaxa 2218:59–68Google Scholar
- Kemper JM, Ebert DA, Naylor G, Didier DA (2015) Chimaera carophila (Chondrichthyes: Chimaeriformes: Chimaeridae), a new species of chimaera from New Zealand. Bull Mar Sci 2015 91(1):63–81Google Scholar
- Kyne PM, Simpfendorfer CA (2012) Deepwater chondrichthyans. In: Carrier JC, Musick JA, Heithaus MR (eds) Biology of sharks and their relatives II. CRC Press, Boca Raton, pp 37–115Google Scholar
- Last PR, Stevens JD (2009) Sharks and rays of Australia. CSIRO Publishing, Collingwood, p 656Google Scholar
- Marshall AD, Compagno LJV, Bennett MB (2009) Redescription of the genus Manta with resurrection of Manta alfredi (Krefft, 1868) (Chondrichthyes; Myliobatoidei; Mobulidae). Zootaxa 2301:1–28Google Scholar
- Pequeño G (1989) Peces de Chile. Lista sistemática revisada y comentada. Rev Biol Mar Oceanogr 24(2):1–132Google Scholar
- Quaranta KL, Didier DA, Long DJ, Ebert DA (2006) A new species of chimaeroid, Hydrolagus alphus sp. nov. (Chimaeriformes: Chimaeridae) from the Galapagos Islands. Zootaxa 1377:33–45Google Scholar
- Sabaj MH (2016) Standard symbolic codes for institutional resource collections in herpetology and ichthyology: an online reference. Version 6.5 (16 August 2016). Electronically accessible at http://www.asih.org/, American Society of Ichthyologists and Herpetologists, Washington, DC