Skip to main content Skip to main navigation menu Skip to site footer
Type: Monograph
Published: 2021-09-03
Page range: 1-96
Abstract views: 758
PDF downloaded: 578

Revision of the ‘dragon-head’ cusk eels of the genus Porogadus (Teleostei: Ophidiidae), with description of eight new species and one new genus

Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark; and Ahrensburger Weg 103, D-22359 Hamburg, Germany.
Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark. Norwegian school of Fisheries, UiT Norwegian Arctic University, Tromsø, Norway
Pisces Porogadus Tenuicephalus Ophidiidae abyssal bathyal new species

Abstract

The ophidiid genus Porogadus occurs between 800 and 5300 m in the tropical and subtropical world oceans. Fifteen nominal species have been described since 1878 and most of them until 1902. The genus has been highlighted as needing revision in recent compilations about ophidiiforms and here we present the first comprehensive review. Twelve of the previously described species are here accepted as valid with two being moved to the newly established genus Tenuicephalus n. gen. that encompasses fishes differing from those of Porogadus in the extremely weak ossification, the stout head, absence of head spines and absence of the “triple” lateral line system considered typical for Porogadus and a reduced dentition. In addition, eight new species are described: Porogadus caboverdensis, P. dracocephalus, P. lacrimatus, P. mendax, P. solomonensis, P. turgidus, Tenuicephalus multitrabs and T. squamilabrus.

                The species of Porogadus show a distinctive depth segregation with the majority of species having a demersal bathyal life-style between 800 and 3500 m and other species being more or less exclusively restricted to abyssal depths below 3000 m. The biogeographic distribution pattern of bathyal groups shows putative species pairs in the Atlantic versus the eastern Pacific and a clear separation of eastern Pacific from Indo-West Pacific species. The geographic effects and timing are being discussed that may have led to this speciation events. Generally, we found widely distributed species that are found far away from continental masses and others restrained to continental slopes and sometimes exhibiting regionalism. In abyssal depth, the Cabo Verde and Canary basins off NW-Africa have yielded three exclusive species, but it is uncertain at this stage whether this could represent a sampling bias with this area being extensively sampled by the Discovery research vessel (BMNH) over the years from 1970–1998. Another instance of a potentially endemic abyssal species is that of Porogadus melanocephalus in the Bay of Bengal. The latter has been caught with 45 specimens in a single trawl, representing the highest number of Porogadus specimens collected in any trawl and indicating that these fishes may actually not be as rare as one might assume from the literature.

 

References

  1. Agusti, S., Gonzáles-Gordillo, J.I., Vaqué, D., Estrada, M., Cerezo, M.I., Saöazar, G., Gasol, J.M. & Duarte, C.M. (2015) Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump. Nature Communications, 6, 7608, 1–8. https://doi.org/10.1038/ncomms8608
    Alcock, A.W. (1890) Natural history notes from H. M. Indian marine survey steamer `Investigator,' Commander R. F. Hoskyn, R. N., commanding. - No. 18. On the bathybial fishes of the Arabian Sea, obtained during the season 1889-1890. Annals and Magazine of Natural History, (Series 6), 6 (34), 295–311. https://doi.org/10.1080/00222939008694038
    Alcock, A.W. (1891) Class Pisces. In: II.- Natural history notes from H. M. Indian marine survey steamer `Investigator,’ Commander R. F. Hoskyn, R. N., commanding. Series II., No. 1. On the results of deep-sea dredging during the season 1890-91. Annals and Magazine of Natural History, (Series 6), 8 (43/44), 16–34 and 119–138. https://doi.org/10.1080/00222939109460385
    Alcock, A.W. (1892) Illustrations of the zoology of the Royal Indian marine surveying steamer Investigator, Fishes. Calcutta. Part 1, pls. 1–7.
    Alcock, A.W. (1896) Natural history notes from H. M. Indian marine survey steamer `Investigator,' Commander C. F. Oldham, R. N., commanding. Series II. No. 23. A supplementary list of the marine fishes of India, with descriptions of two new genera and eight new species. Journal of the Asiatic Society of Bengal, 65 (3), 301–338.
    Alcock, A.W. (1897) Illustrations of the zoology of the Royal Indian marine surveying steamer Investigator, Fishes. Calcutta. Part 4, pl. 17.
    Alcock, A.W. (1898) Illustrations of the zoology of the Royal Indian marine surveying steamer Investigator, Fishes. Calcutta. Part 5, ps. 18–24.
    Anderson Dahl, C. (2009) Neogene Climates. In (Gornitz, V. ed.): Encyclopedia of Palaeoclimatology and Acient Environments. Springer Science+Business Media B.V., Dordrecht, 4 pp.
    Bell, K.L.C., Elliott, K., Martinez, C. & Fuller, S.A. eds. (2012) New Frontiers in Ocean Exploration: The E/V Nautilus and NOAA Ship Okeanos Explorer 2011 field season. Oceanography, 25 (1), supplement, 68 pp. https://doi.org/10.5670/oceanog.2011.supplement.01.
    Bell, K.L.C., Brennan, M.L., Flanders, J., Raineault, N.A & Wagner, K. eds. (2016) New frontiers in ocean exploration: The E/V Nautilus and NOAA Ship Okeanos Explorer 2015 field season. Oceanography, 29 (1), supplement, 84 pp. https://doi.org/10.5670/oceanog.2016.supplement.01.
    Bell, K.L.C., Flanders, J., Bowman, A. & Raineault, N.A. eds. (2017) New frontiers in ocean exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2016 field season. Oceanography, 30 (1), supplement, 94 pp. https://doi.org/10.5670/oceanog.2017.supplement.01.
    Burton, K.W., Ling, H.-F. & O’Nions, R.K. (1997) Closure of the Central American Isthmus and its effect on deep-water formation in the North Atlantic. Nature, 386, 27, 382–386. https://doi.org/10.1038/386382a0
    Carter, H.C. (1984) Feeding strategies and functional morphology of demersal deep-sea ophidiid fishes. PhD dissertation, The Faculty of the School of Marine Science The College of William and Mary in Virginia, 236 pp.
    Carter, H.C. & Sulak, K.J. (1984) A new species and a review of the deep-sea fish genus Porogadus (Ophidiidae) from the western north Atlantic. Bulletin of Marine Science, 34 (3), 358–379.
    Castellanos-Galindo, G.A., Rincon, E.A.R., Beltrán-Léon, B., Zapata, L.A. & Baldwin, C.C. (2006) Check list of gadiform, ophidiiform and lophiiform fishes from Colombian waters of the tropical eastern Pacific. Biota Colombiana, 7 (2), 191–209.
    Chave, E.H. & Mundy, B.C. (1994) Deep-sea benthic fish of the Hawaiian Archipelago, Cross Seamount, and Johnston Atoll. Pacific Science, 48 (4), 367–409.
    Cohen, D.M. & Nielsen, J.G. (1978) Guide to the identification of genera of the fish order Ophidiiformes with a tentative classification of the order. NOAA Technical Report NMFS, 417, 1–72. https://doi.org/10.5962/bhl.title.63242
    Diester-Haass, L. & Schrader, H.-J. (1979) Neogene coastal upweling history off northwest and southwest Africa. Marine Geology, 29, 39–53. https://doi.org/10.1016/0025-3227(79)90101-4
    Fahay, M.P. (2007) Early stages of fishes in the western North Atlantic Ocean (Davis Strait, southern Greenland and Flemish Cap to Cape Hatteras). West Bath, Maine, 1696 pp.
    Filipelli, G. (2014) A salty start to modern ocean circulation. Science, 344 (6189), 1228–1229. https://doi.org/10.1126/science.1255553
    Fricke, R. & Eschmeyer, W. (2013) A Guide to Fish Collections in the Catalog of Fishes Database. In: Catalogue of Fishes. Internet publication, http://research.calacademy.org/research/Ichthyology/Catalog/collections.asp.
    Fricke, R., Allen, G.R., Andréfouet, S., Chen, W.-J., Hamel, M.A., Laboute, P., Mana, R., Hui, T.H. & Uyeno, D. (2014) Checklist of the marine and estuarine fishes of Madang District, Papua New Guinea, western Pacific Ocean, with 820 new records. Zootaxa, 3832, 1–247. https://doi.org/10.11646/zootaxa.3832.1.1
    Gallo, N.D., Levin, L.A., Beckwith, M. & Barry, J.P. (2019) Home sweet suboxic home: remarkable hypoxia tolerance in two demersal fish species in the Gulf of California. Ecology, 100 (3), e02539, 1–5. https://doi.org/10.1002/ecy.2539
    Garman, S. (1899) The Fishes. In: Reports on an exploration off the west coasts of Mexico, Central and South America, and off the Galapagos Islands, in charge of Alexander Agassiz, by the U. S. Fish Commission steamer "Albatross," during 1891, Lieut. Commander Z. I. Tanner, U. S. N. commanding. No. XXV, the fishes. Memoires of the Museum of Comparative Zoology, 24, 1–431. https://doi.org/10.5962/bhl.part.27494
    Gerringer, M.E. (2019) On the success of hadal snailfishes. Integrative Organismal Biology, 1–18. https://doi.org/10.1093/iob/obz004
    Gilbert, C.H. (1892) Descriptions of thirty-four new species of fishes collected in 1888 and 1889, principally among the Santa Barbara Islands and in the Gulf of California. In: Scientific results of explorations by the U. S. Fish Commission steamer Albatross. Proceedings of the United States National Museum, 14 (880), 539–566. https://doi.org/10.5479/si.00963801.14-880.539
    Gladenkov, Y.B. (1994) Cenozoic paleogeography and climatic change in the North Pacific Ocean. Palaeogeography, Palaeoclimatology, Palaeoecology, 108, 311–318. https://doi.org/10.1016/0031-0182(94)90239-9
    Goode, G.B. & Bean, T.H. (1885) Descriptions of new fishes obtained by the United States Fish Commission mainly from deep water off the Atlantic and Gulf coasts. Proceedings of the United States National Museum, 8 (543), 589–605. https://doi.org/10.5479/si.00963801.8-543.589
    Goode, G.B. & Bean, T.H. (1896) Oceanic ichthyology, a treatise on the deep-sea and pelagic fishes of the world, based chiefly upon the collections made by the steamers Blake, Albatross, and Fish Hawk in the northwestern Atlantic, with an atlas containing 417 figures. Special Bulletin U. S. National Museum, 2, i–xxxv + 1–26 + 1–553.
    Grey, M. (1956) The distribution of fishes found below a depth of 2000 m. Fieldiana Zollogy, 36 (2), 77–337. https://doi.org/10.5962/bhl.title.2788
    Grey, M. (1958) Descriptions of abyssal benthic fishes from the Gulf of Mexico. Fieldiana Zoology, 39 (16), 149–183. https://doi.org/10.5962/bhl.title.3323
    Günther, A. (1878) Preliminary notices of deep-sea fishes collected during the voyage of H. M. S. `Challenger'. Annals and Magazine of Natural History, (Series 5), 2 (7/8/9), 17–28, 179–187 + 248–251. https://doi.org/10.1080/00222937808682417
    Günther, A. (1887) Report on the deep-sea fishes collected by H.M.S. Challenger duribg the years 1873-1876. Zoological Challenger Expedition, 5 (22), 1–335. https://doi.org/10.5962/bhl.title.15693
    Hanke, G., Gillespie, G., Fong, K., Boutillier, J., Nielsen, J., Møller, P., Bedard, J. & Riley, J. (2015) New records of seven cusk-eels (Ophidiidae) and brotulas (Bythitidae) in coastal waters of British Columbia, Canada. Northwestern Naturalist, 96, 71–80. https://doi.org/10.1898/NWN14-17.1
    Hubbs, C.L. & Lagler, K.F. (1958) Fishes of the Great Lakes region. Cranbrook Institute of Science Bulletin, 26, 1–213.
    Jackson, J.B.C. & O’Dea, A. (2013) Timing of the oceanographic and biological isolation of the Caribbean Sea from the tropical eastern Pacific Ocean. Bulletin of Marine Science, 89 (4), 779–800.
    Jordan, D.S. & Evermann, B.F. (1898) The fishes of North and Middle America. Bulletin of the U.S. national Museum, 47 (111), 2183–3136.
    Jordan, D.S. & Evermann, B.F. (1900) The fishes of North and Middle America: a descriptive catalogue of the species of fish-like vertebrates found in the waters of North America, north of the Isthmus of Panama. Part IV. Bulletin of the United States National Museum, 47, 3137–3313. https://doi.org/10.5962/bhl.title.39720
    Jordan, D.S. & Fowler, H.W. (1902) A review of the ophidioid fishes of Japan. Proceedings of the United States National Museum, 25 (1303), 743–766. https://doi.org/10.5479/si.00963801.25-1303.743
    Kamikuri, S.-i., Motoyama, I., Nishi, H. & Iwai, M. (2009) Evolution of Eastern Pacific warm pool and upwelling process since the middle Miocene based on analysis of radiolarian assemblages: Response to Indonesian and Central American seaways. Palaeogeography, Palaeoclimatology, Palaeoecology, 280, 469–479. https://doi.org/10.1016/j.palaeo.2009.06.034
    Kennedy, B., Demopoulos, A. & Auscavitch, S. (2017). Oceanographic data and information collected during the EX1703 Howland/Baker PRIMNM and PIPA (ROV/Mapping) expedition on NOAA Ship OKEANOS EXPLORER in the South Pacific Ocean from 2017-03-07 to 2017-03-29 (NCEI Accession 0162616). NOAA National Centers for Environmental Information. Available from: https://doi.org/10.7289/v5sj1hw0. (accessed 08 August 2020)
    Kennedy, B., France, S. & Gerringer, M. (2019). Oceanographic data and ROV dive-related multimedia and information collected during the EX1504L4 (Campaign to Address Pacific monument Science, Technology, and Ocean NEeds (CAPSTONE) Leg IV) expedition on NOAA Ship OKEANOS EXPLORER in the North Pacific Ocean from 2015-09-07 to 2015-09-30 (NCEI Accession 0131887). NOAA National Centers for Environmental Information. Dataset. Available from: https://doi.org/10.7289/v5gb223t (accessed 08 August 2020)
    Linley, T.D., Stewart, A.L., McMillan, P.J., Clark, M.R., Gerringer, M.E., Drazen, J.C., Fujii, T. & Jamieson, A.J. (2017) Bait attending fishes of the abyssal zone and hadal boundary: Community structure, functional groups and species distribution in the Kermadec, New Hebrides and Mariana trenches. Deep-Sea Research I, 121, 38–53. https://doi.org/10.1016/j.dsr.2016.12.009
    Machida, Y. (1982) Rare ophidiid fish, Porogadus guentheri, from Japanese waters. Reports of the Usa Marine Biological Institute, Kochi University, 4, 27–33.
    Machida, Y. (1984) Order Ophidiiformes. In (Masuda, H., Amaoka, K., Araga, C., Uyeno, T. & Yoshino, T. eds.) The fishes of the Japanese Archipelago. Tokyo (Tokai University Press), 99–101.
    Machida, Y. (1984) Ophidiidae. In (Okamura, O. & Kitajima, T. eds.) Fishes of the Okinawa Trough and the adjacent waters. Vol. I. The intensive research of unexploited fishery resources on continental slopes. Japan Fisheries Resource Conservation Association, Tokyo, 261, 375.
    Machida, Y. & Amaoka, K. (1990) Pacific records of the deep-sea fish Porogadus miles (Ophidiiformes, Ophidiidae). Japanese Journal of Ichthyology, 37 (1), 64–68.
    Masuda, H., Amaoka, K., Araga, C., Uyeno, T. & Yoshino, T. (1984) The fishes of the Japanese Archipelago. Tokai University Press, Tokyo, 437 pp.
    Merrett, N.R. (2000) Fishes. In (Partridge, J.C. ed.) Sensory biology in the deep-sea: anatomy, physiology, and molecular biology. Cruise Report, RRS Discovery Cruise 243, 11th October to 22nd November 1999, 50.
    Merrett, N.R. & Marshall, N.B. (1981) Observations on the ecology of deep-sea bottom-living fishes collected off northwest Africa (08°–27°N). Progress Oceanography, 9, 185–244. https://doi.org/10.1016/0079-6611(80)90002-6
    Mincarone, M.M., Nielsen, J.G. & Costa, P.A.S. (2007) Deep-sea ophidiiform fishes collected on the Brazilian continental slope, between 11° and 23°S. Zootaxa, 1770 (1), 41–64. https://doi.org/10.11646/zootaxa.1770.1.2
    Morley, J.J. & Dworetzky, B.A. (1991) Evolving Pliocene-Pleistocene climate: a north Pacific perspective. Quaternary Science Reviews, 10, 225–237. https://doi.org/10.1016/0277-3791(91)90021-L
    Mundy, B.C., Gerringer, M.E., Nielsen, J.G., Fryer, P. & Leitner, A. (2018) First in situ observation of an aphyonid fish (Teleostei, Ophidiiformes, Bythitidae). Deep-Sea Research Part II, 150, 164–169. https://doi.org/10.1016/j.dsr2.2017.09.009
    Nielsen, J. G. & Machida, Y. (1988) Revision of the Indo-west Pacific bathyal fish genus Glyptophidium (Ophidiiformes, Ophidiidae). Japanese Journal of Ichthyology, 35 (3), 289–319. https://doi.org/10.1007/BF02938429
    Nielsen, J.G., Cohen, D.M., Markle, D.F. &vRobins, C.R. (1999) Ophidiiform fishes of the world (Order Ophidiiformes). FAO Fisheries Synopsis, 125, FAO Species Catalogue, 18, 1–178.
    Nielsen, J.G. & Møller, P.R. (2007) New and rare deep-sea ophidiiform fishes from the Solomon Sea caught by the Danish Galathea 3 Expedition. Steenstrupia, 30 (1), 21–46.
    Nolf, D. (1980) Etude monographique des otolithes des Ophidiiformes actuels et révision des espèces fossiles (Pisces, Teleostei). Mededelingen van de Werkgroep voor Tertiaire en Kwartaire Geologie, 17 (2), 71–195.
    Norman, J.R. (1939) Fishes. The John Murray Expedition 1933-1934 Scientific Reports, 7, 1–116.
    Nybelin, O. (1957) Deep-sea bottom fishes. Reports of the Swedish Deep-Sea Expedition 1947-1948, 2, 247–345.
    Ocean Networks Canada, SeaTube Pro (2017) NOAA OER Howland/Baker Islands EX1703, Dive 16. Available from: https://data.oceannetworks.ca/SeaTube (accessed 12 August 2020)
    Pelegrí, J.L., Peña-Izquierdo, J., Machín, F., Meiners, C. & Presas-Navarro, C. (2017) Oceanography of the Cape Verde Basin and Mauritanian Slope Waters. In: Ramos A., Ramil, F. & Sanz, J. (Eds.), Deep-Sea Ecosystems Off Mauritania. Springer, Dordrecht, 119–153. https://doi.org/10.1007/978-94-024-1023-5_3
    Potter, R.A. & Lozier, M.S. (2004) On the warming and salinification of the Mediterranean outflow waters in the North Atlantic. Geophysical Research Letters, 31, L01202, 1–4. https://doi.org/10.1029/2003GL018161
    Priede, I.G., Drazen, J.C., Bailey, D.M., Kuhnz, L.A. & Fabian, D. (2019) Abyssal demersal fishes recorded at station M (34°50’N, 123°00’W, 4100 m depth) in the northeast Pacific Ocean: An annotated check list and synthesis. Deep-Sea esearch Part II, 173, 104648. https://doi.org/10.1016/j.dsr2.2019.104648
    Prokofiev, A.M. (2005) On some rare ophidiiform fishes from the South Atlantic and Indo-West Pacific, with erection of a new genus, Megacataetyx gen. novum (Teleostei: Ophidiiformes). Estestvennye i technicheskie Nauki, 2, 111–128.
    Raineault, N.A, Flanders, J. & Bowman, A. eds. (2018) New frontiers in ocean exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2017 field season. Oceanography, 31 (1), supplement, 126 pp. https://doi.org/10.5670/oceanog.2018.supplement.01
    Raineault, N.A. & Flanders, J. eds. (2019) New frontiers in ocean exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2018 field season. Oceanography, 32(1), supplement, 150 pp. https://doi.org/10.5670/oceanog.2019.supplement.01
    Raineault, N.A. & Flanders, J. eds. (2020) New frontiers in ocean exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2019 field season. Oceanography, 33 (1), supplement, 122 pp. https://doi.org/10.5670/oceanog.2020.supplement.01
    Ramiro-Sánchez, B., González-Irusta, J.M., Henry, L.-A., Cleland, J., Yeo, I., Xavier, J.R., Carreiro-Silva, M., Sampaio, I., Spearman, J., Victorero, L., Messing, C.G., Kazanidis, G., Roberts, J.M. & Murton, B. (2019) Characterization and mapping of a deep-sea sponge ground on the Tropic Seamount (northeast tropical Atlantic): Implications for spatial management in the high sea. Frontiers in Marine Science, 6, 278, 1–19. https://doi.org/10.3389/fmars.2019.00278
    Schwarzhans, W. (1981) Vergleichende morphologische Untersuchungen an rezenten und fossilen Otolithen der Ordnung Ophidiiformes. Berliner Geowissenschaftliche Abhandlungen, A, 32, 63–122.
    Schwarzhans, W. (1993) A comparative morphological treatise of recent and fossil otoliths of the family Sciaenidae. Piscium Catalogus, Otolithi Piscium, 1, 1–245.
    Schwarzhans, W. (2010) Otolithen aus den Gerhartsreiter Schichten (Oberkreide: Maastricht) des Gerhartsreiter Grabens (Oberbayern). Palaeo Ichthyologica, 4, 1–100.
    Schwarzhans, W. & Aguilera, O. (2013) Otoliths of the Myctophidae from the Neogene of tropical America. Palaeo Ichthyologica, 13, 83–150.
    Schwarzhans, W. & Møller, P.R. (2008) Review of the Dinematichthyini (Teleostei: Bythitidae) of the Indo-West Pacific. Part III. Beaglichthys, Brosmolus, Monothrix and eight new genera with description of 20 new species. The Beagle, Records of the Museums and Art Galleries of the Northern Territory, 23, 29–110.
    Schwarzhans, W.W. & Prokofiev, A.M. (2017) Reappraisal of Synagrops Günther, 1887 with rehabilitation and revision of Parascombrops Alcock, 1889 including description of seven new species and two new genera Perciformes: Acropomatidae). Zootaxa, 4260 (1), 1–74. https://doi.org/10.11646/zootaxa.4260.1.1
    Shcherbachev, Y.N. (1980) A preliminary review of deep-sea ophidiids (Ophidiidae, Ophidiiformes) of the Indian Ocean.Trudy Okeanography Institut, 110, 86–94.
    Shinohara, G., Sato, T., Aonuma, Y., Horikawa, H., Matsuura, K., Nakabo, T. & Sato, K. (2005) Annotated checklist of deep-sea fishes from the waters around the Ryukyu Islands, Japan. In (Hasegawa, K., Shinohara, G. &Takeda, M., eds.) Deep-sea fauna and pollutants in the Nansei Islands. National Museum of Nature and Science Monographs, 29, 385–452.
    Shinohara, G., Narimatsu, Y., Hattori, T., Ito, M., Takata, Y. & Matsuura, K. (2009) Annotated checklist of deep-sea fishes from the Pacific coast off Tohoku District, Japan. In: Fujita, T. (Ed.), Deep-sea fauna and pollutants off Pacific coast of northern Japan. National Museum of Nature and Science Monographs, 39, 683–735.
    Tsuchi, R. (2002) Neogene evolution of surface marine climate in the Pacific and notes on related events. Revista Mexicana de Ciencias Geológicas, 19 (3), 260–270.
    Vaillant, L.L. (1888) Expéditions scientifiques du “Travailleur” et du “Talisman” pendant les années 1880, 1881, 1882, 1883. Poissons. Paris, 1–406. https://doi.org/10.5962/bhl.title.13677
    Watling, L., Guinotte, J., Clark, M.R. & Smith, C.R. (2013) A proposed biogeography of the deep ocean floor. Progress in Oceanography, 111, 91–112. https://doi.org/10.1016/j.pocean.2012.11.003
    Wilson, R.R. (1985) Depth-related changes in sagitta morphology in six macrourid fishes of the Pacific and Atlantic oceans. Copeia, 1985 (4), 1011–1017. https://doi.org/10.2307/1445256