Skip to main content Skip to main navigation menu Skip to site footer
Responsive image
Issue: Vol. 5828 No. 3: 10 Jun. 2026
Type: Article
Published: 2026-06-10
DOI: 10.11646/zootaxa.5828.3.7
Page range: 535-548
Abstract views: 254
PDF downloaded: 6

A new species of Rhinochimaera Garman 1901 (Holocephali: Chimaeriformes: Rhinochimaeridae) from the Eastern Pacific Ocean

Escuela de Biología; Museo de Zoología/Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET); and Centro de Investigación en Ciencias del Mar y Limnología (CIMAR); Universidad de Costa Rica; ICtioCR; San Pedro de Montes de Oca; San José; Costa Rica
Instituto Costarricense de Pesca y Acuacultura (INCOPESCA); Barrio El Cocal; Puntarenas; Costa Rica
Instituto Costarricense de Pesca y Acuacultura (INCOPESCA); Barrio El Cocal; Puntarenas; Costa Rica
Instituto Costarricense de Pesca y Acuacultura (INCOPESCA); Barrio El Cocal; Puntarenas; Costa Rica
Laboratory of Fish Microbiology; Institute of Coastal Studies; Federal University of Para (UFPA); Alameda Leandro Ribeiro s/n; Braganca; Para; Brazil
Laboratório de Genética e Conservação (LGC); Instituto de Estudos Costeiros (IECOS); Universidade Federal do Pará (UFPA); Alameda Leandro Ribeiro S/N; Bragança; PA; Brazil
Escuela de Biología; Museo de Zoología/Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET); and Centro de Investigación en Ciencias del Mar y Limnología (CIMAR); Universidad de Costa Rica; ICtioCR; San Pedro de Montes de Oca; San José; Costa Rica
Pisces Rhinochimaera costaricana sp. nov Central America Costa Rica Taxonomy Diversity Chondrichthyans Deep-sea

Abstract

A new species of Rhinochimaera is described based on a unique combination of morphological traits, further supported by molecular evidence. The type series comprises three males (775–830 mm total length) collected off the Pacific coast of Costa Rica between 2000 and 2023, at depths of 390–787 m. A total of 49 morphometric measurements were obtained from the three specimens and compared with published and unpublished data from 90 additional specimens representing the three currently recognized species of Rhinochimaera. Rhinochimaera costaricana sp. nov. is distinguished from its congeners by a shorter snout, a larger and taller first dorsal-fin spine, a higher first dorsal fin, a wider interdorsal space, and a reduced number of caudal tubercles. Molecular analyses of COI sequences from two specimens of R. costaricana sp. nov. revealed genetic divergences of 3.9% from R. africana, 4.5% from R. atlantica, and 4.7% from R. pacifica, exceeding the commonly accepted interspecific divergence threshold. Species delimitation methods (ASAP, bPTP, GMYC) likewise support the recognition of this taxon as distinct from all congeners. This discovery improves our knowledge of deep-sea fish diversity in the region and underscores the importance of integrative approaches in species identification, delimitation, and characterization

References

  1. Bouckaert, R., Vaughan, T.G., Barido-Sottani, J., Duchêne, S., Fourment, M., Gavryushkina, A., Heled, J., Jones, G., Kühnert, D., De Maio, N., Matschiner, M., Mendes, F.K., Müller, N.F., Ogilvie, H.A., du Plessis, L., Popinga, A., Rambaut, A., Rasmussen, D., Siveroni, I., Suchard, M.A., Wu, C.-H., Xie, D., Zhang, C., Stadler, T. & Drummond, A.J. (2019) BEAST 2.5: An advanced software platform for Bayesian evolutionary analysis. PLoS Computational Biology, 15, e1006650. https://doi.org/10.1371/journal.pcbi.1006650
  2. Compagno, L.J.V., Stehmann, M. & Ebert, D.A. (1990) Rhinochimaera africana, a new longnose chimaera from southern Africa, with comments on the systematics and distribution of the genus Rhinochimaera Garman, 1901 (Chondrichthyes, Chimaeriformes, Rhinochimaeridae). African Journal of Marine Science, 9 (1), 201–222. https://doi.org/10.2989/025776190784378646
  3. Didier, D.A. & Meckley, T. (2009) Rhinochimaeridae. In: Nakaya, K., Yabe, M., Imamura, H., Romero, M.C. & Yoshida, M. (Eds.), Deep-sea fishes of Peru. Japan Deep Sea Trawlers Association, Tokyo, pp. 49–50.
  4. Didier, D.A. & Nakaya, K. (1999) Redescription of Rhinochimaera pacifica (Mitsukuri) and first record of R. africana Compagno, Stehmann & Ebert from Japan (Chimaeriformes: Rhinochimaeridae). Ichthyological Research, 46 (2), 139–152. https://doi.org/10.1007/bf02675432
  5. Ebert, D.A. (2016) Deep-sea Cartilaginous Fishes of the Southeastern Pacific Ocean. FAO Species Catalogue for Fishery Purposes, Rome, 241 pp. Available from: https://www.fao.org/3/i6389e/i6389e.pdf (accessed 21 August 2025)
  6. Finucci, B., Didier, D., Ebert, D.A., Green, M.E. & Kemper, J.M. (2024) Harriotta avia sp. nov.—a new rhinochimaerid (Chimaeriformes: Rhinochimaeridae) from the Southwest Pacific. Environmental Biology of Fishes, 107, 841–865. https://doi.org/10.1007/s10641-024-01577-4
  7. Fricke, R., Eschmeyer, W.N. & Fong, J.D. (2025a) Eschmeyer’s Catalog of Fishes: Genera/species by family/subfamily. Available from: http://researcharchive.calacademy.org/research/ichthyology/catalog/SpeciesByFamily.asp (accessed 21 August 2025)
  8. Fricke, R., Eschmeyer, W.N. & Van der Laan, R. (Eds.) (2025b) Eschmeyer’s Catalog of Fishes: Genera, species, references. Available from: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp (accessed 21 August 2025)
  9. Fujisawa, T. & Barraclough, T.G. (2013) Delimiting species using single-locus data and the generalized mixed Yule coalescent approach: A revised method and evaluation on simulated data sets. Systematic Biology, 62, 707–724. https://doi.org/10.1093/sysbio/syt033
  10. Hall, T.A. (1999) BioEdit: A user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series, 41, 95–98.
  11. Iglésias, S.P., Kemper, J.M. & Naylor, G.J. (2022) Chimaera compacta, a new species from the southern Indian Ocean, and an estimate of phylogenetic relationships within the genus Chimaera (Chondrichthyes: Chimaeridae). Ichthyological Research, 69 (1), 31–45. https://doi.org/10.1007/s10228-021-00847-0
  12. Inada, T. & Garrick, J.A.F. (1979) Rhinochimaera pacifica, a long-snouted chimaera (Rhinochimaeridae), in New Zealand waters. Japanese Journal of Ichthyology, 25 (4), 235–243.
  13. Krajangdara, T., Ebert, D.A., Chaorattana, C. & Khudamrongsawat, J. (2021) Morphological and genetic evidence confirming three new records of ghost shark species (Chimaeriformes) from the Andaman Sea of Thailand. Tropical Natural History, 21 (2), 218–233. https://doi.org/10.58837/tnh.21.2.245840
  14. Kumar, S., Stecher, G., Li, M., Knyaz, C. & Tamura, K. (2018) MEGA X: Molecular evolutionary genetics analysis across computing platforms. Molecular Biology and Evolution, 35, 1547–1549. https://doi.org/10.1093/molbev/msy096
  15. Nguyen, L.-T., Schmidt, H.A., von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: A fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32, 268–274. https://doi.org/10.1093/molbev/msu300
  16. Paithankar, K.R. & Prasad, K.S.N. (1991) Precipitation of DNA by polyethylene glycol and ethanol. Nucleic Acids Research, 19, 1346. https://doi.org/10.1093/nar/19.6.1346
  17. Pons, J., Barraclough, T.G., Gomez-Zurita, J., Cardoso, A., Duran, D.P., Hazell, S., Kamoun, S., Sumlin, W.D. & Vogler, A.P. (2006) Sequence-based species delimitation for the DNA taxonomy of undescribed insects. Systematic Biology, 55, 595–609. https://doi.org/10.1080/10635150600852011
  18. Puillandre, N., Brouillet, S. & Achaz, G. (2021) ASAP: Assemble species by automatic partitioning. Molecular Ecology Resources, 21 (2), 609–620. https://doi.org/10.1111/1755-0998.13281
  19. Rambaut, A., Drummond, A.J., Xie, D., Baele, G. & Suchard, M.A. (2018) Posterior summarization in Bayesian phylogenetics using Tracer 1.7. Systematic Biology, 67, 901–904. https://doi.org/10.1093/sysbio/syy032
  20. Sabaj, M.H. (2025) Codes for Natural History Collections in Ichthyology and Herpetology (online supplement). Version 9.7. American Society of Ichthyologists and Herpetologists, Washington, DC. Available from: https://www.asih.org/resources/standard-symbolic-codes (accessed 21 August 2025)
  21. Shao, K.T. & Hwang, D.F. (1997) Rhinochimaera pacifica (Chimaeriformes, Rhinochimaeridae), the first rhinochimaerid recorded from Taiwan. Acta Zoologica Taiwanica, 8 (2), 97–102.
  22. Silva, T.F. da, Sampaio, I., Angulo, A., Domínguez-Domínguez, O., Andrade-Santos, J., Guimarães-Costa, A. & Santos, S. (2023) Species delimitation by DNA barcoding reveals undescribed diversity in Stelliferinae (Sciaenidae). PLoS ONE, 18 (12), e0296335. https://doi.org/10.1371/journal.pone.0296335
  23. Ward, R.D., Zemlak, T.S., Innes, B.H., Last, P.R. & Hebert, P.D.N. (2005) DNA barcoding Australia’s fish species. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 360, 1847–1857. https://doi.org/10.1098/rstb.2005.1716
  24. Weigmann, S. (2016) Annotated checklist of the living sharks, batoids and chimaeras (Chondrichthyes) of the world, with a focus on biogeographical diversity. Journal of Fish Biology, 88 (3), 837–1037. https://doi.org/10.1111/jfb.12874
  25. Zhang, J., Kapli, P., Pavlidis, P. & Stamatakis, A. (2013) A general species delimitation method with applications to phylogenetic placements. Bioinformatics, 29, 2869–2876. https://doi.org/10.1093/bioinformatics/btt499

How to Cite

Vidaurre-Quesada, N.V., Salas-Jimenez, A., Carvajal-Rodriguez, J.M., Lara-Quesada, N., Santos, S., Araripe, J. & Angulo, A. (2026) A new species of Rhinochimaera Garman 1901 (Holocephali: Chimaeriformes: Rhinochimaeridae) from the Eastern Pacific Ocean. Zootaxa, 5828 (3), 535–548. https://doi.org/10.11646/zootaxa.5828.3.7