Eurypterygii caudal skeleton



The osteology of the caudal skeleton in representatives of 41 genera in 39 families of eurypterygian fishes was studied. The caudal skeleton of eurypterygian fishes consists of five or six hypurals, a parhypural, one to three epurals, one or two pairs of uroneurals, ural centra 1 and 2, last preural centra and associated neural and haemal spines, and procurrent and principal rays. Eurypterygians like other teleosts have a diural caudal skeleton (two ural cen-tra). Primitively in basal Acanthomorpha and Acanthopterygii, the caudal elements are autog-enous and several intercaudal and postcaudal cartilages support these isolated elements. Basal groups usually have six autogenous hypurals, three epurals, two pairs of autogenous neurals, autogenous ural centrum 2, and autogenous haemal and neural spines on the last centra. In some basal groups such as Myctophidae, many of the caudal elements are fused, because of the presence of primitive conditions in related taxa, the fusion in such a groups should be re-garded as secondary and independent from that in higher taxa. In higher groups, there is a tendency for the elements to fuse together and to the centra and caudal cartilage are lost due to lack of function. In specialized groups


Bones, Cartilage, Eurypterygians, Tail, Osteology, Skeleton.

Full Text:



Baldwin, C.C. & Johnson, G.D. 1996. Interrelation-ships of Aulopiformes. In Stiassny, M.L.J.; Parenti, L.R. & Johnson, G.D. (eds.). Interre-lationships of fishes. Academic Press, San Diego, USA. pp. 355-404.

Balushkin, A.V. 1996. A new genus and species of liparid fish Palmoliparis beckeri from the Northern Kurile Islands (Scorpaeniformes, Liparidae) with consideration of phylogeny of the family. Journal of Ichthyology 36: 281-287.

Bowne, P.S. 1985. The systematic position of Gas-terosteiformes. PhD dissertation. Department of Zoology. University of Alberta, Edmon-ton, Canada. 461p.

Cope, E.D. 1890. The homologies of the fins of fishes. American Naturalists 14: 401-423.

de Pinna, M.C.C. 1996. Teleostean monophyly. In Stiassny, M.L.J.; Parenti, L.R. & Johnson, G.D. (eds.). Interrelationships of fishes. Aca-demic Press, San Diego, USA. pp. 147-162.

Doyle, K.D. 1998. Osteology of Dactyloscopus tri-digitatus (Dactyloscopidae: Blennioidei). Bulletin of Marine Science 63: 51-81.

Fujita, K. 1990. The caudal skeleton of teleostean fishes. Tokai University Press, Japan. 897p.

Fujita, K. & Oozeki, Y. 1994. Development of the caudal skeleton in the saury, Cololabis saira. Japanese Journal of Ichthyology 41: 334-337.

Ghedotti, M.J. 1998. Phylogeny and classification of the Anablepidae (Teleostei: Cyprinodonti-formes). In: Phylogeny and classification of neotropical fishes. pp. 561-582.

Gill, A.C. & Mooi, R.D. 1993. Monophyly of the Grammatidae and of the Notograptidae, with evidence for their phylogenetic positions among perciforms. Bulletin of Marine Sci-ence 52: 327-350.

Gomon, M.F. 1997. Relationships of fishes of the labrid tribe Hypsigenyini. Bulletin of Marine Science 60: 789-871.

Gosline, W.A. 1960. Contributions toward a classi-fication of modern isospondylous fishes. Bul-letin of British museum of Natural History (Zoology) 6: 325-365.

Gosline, W.A. 1961. Some osteological features of modern lower teleostean fishes. Smithson. Miscellaneous Collections 142: 1-42.

Greenwood, P.H. 1976. A review of the family Cen-tropomidae (Pisces, Perciformes). Bulletin of British museum of Natural History (Zoology) 29: 1-80.

Hoese, D.F. & Gill, A.C. 1993. Phylogenetic rela-tionships of Eleotridid fishes (Perciformes: Gobioidei). Bulletin of Marine Science 52: 415-440.

Hollister, G. 1936. Caudal skeleton of Bermuda shallow water fishes. I. order Isospondyli: Elopidae, Megalopidae, Albulidae, Cludei-dae, Dussumieridae, Engraulidae. Zoologica 21: 257-290.

Jalili, P.; Eagderi, S.; Nikmehr, N. & Keivany, Y. 2015. Descriptive osteology of Barbus cyri (Teleostei: Cyprinidae) from southern Cas-pian Sea basin. Iranian Journal of Ichthyol-ogy 2(2): 105-112.

Johnson, G.D.; Baldwin, C.C.; Okiyama, M. & Tominaga, Y. 1996. Osteology and relation-ships of Pseudotrichonotus altivelis (Tele-ostei: Aulopiformes: Pseudotrichonotidae). Ichthyological Research 43: 17-45.

Kanayama, T. 1991. Taxonomy and phylogeny of the family Agonidae (Pisces: Scorpaeni-formes). Memoires of the Faculty of Fisher-ies, Hokkaido University 38: 1-199.

Keivany, Y. 1996. Taxonomic revision of the genus Pungitius with emphasis on P. hellenicus. MSc. thesis. Department of Biological Sci-ences, University of Alberta, Edmonton, Canada. 98p.

Keivany, Y. 2000. Phylogenetic relationships of Gasterosteiformes (Teleostei, Percomorpha). PhD. thesis. Department of Biological Sci-ences. University of Alberta, Edmonton, Canada. 201p.

Keivany, Y. 2014a. Comparative osteology of the jaws in representatives of the eurypterygian fishes. Research in Zoology 4(2): 29-42.

Keivany, Y. 2014b. Comparative osteology of the suspensorial and opercular series in repre-sentatives of the eurypterygian fishes. Iranian Journal of Ichthyology 1(2): 73-90.

Keivany, Y. 2014c. Osteology of hyobranchials in eurypterygian fishes. Iranian Journal of Ich-thyology 1(3): 129–151.

Keivany, Y. 2014d. Pectoral girdle bones in euryp-terygian fishes. International Journal of Aquatic Biology 2(5): 253-274.

Keivany, Y. 2017. Comparative osteology of the pelvic girdle in eurypterygian fishes. Iranian Journal of Sciences: In press.

Keivany, Y. & Nelson, J.S. 1998. Comparative os-teology of the Greek ninespine stickleback, Pungitius hellenicus (Teleostei, Gasterostei-dae). Journal of Ichthyology 38: 430-440.

Keivany, Y.; Nelson, J.S. & Economidis, P.S. 1997, Validity of Pungitius hellenicus, a stickle-back fish from Greece. Copeia 1997(3): 558-564.

Kölliker, A. 1860. Über das ende der wirbelsaule der ganoiden und einiger teleostier. Leipzig. 4: 1-27.

Kotlyar, A.N. 1991a. Osteology of fish of the sub-order Stephanoberycoidei. 2. Melamphaidae. Journal of Ichthyology 31: 100-116.

Kotlyar, A.N. 1991b. Osteology of the suborder Stephanoberycoidei. Communication 1. The Stephanoberycidae and Gibberichthyidae. Journal of Ichthyology 31: 18-32.

Kotlyar, A.N. 1992. Osteology of Sorosichthys ana-nassa and its position in the systematics of Beryciform fishes (Beryciformes). Journal of Ichthyology32: 56-68.

Lotz, T. 1864. Über den bau der schwanzwir-belsäule der salmoniden, cyprinoiden, percoi-den und cataphracten. Zeitschrift für wissen-schaftliche Zoologie 14: 81-106.

Mok, H.K. 1983. Osteology and phylogeny of Squa-mipinnes. Taiwan Museum Special Publica-tions Series (1): 1-87.

Monad, T. 1968. Le compléxe urophore des poisson teleostéen. Memoires de l'Institut Fundamen-tal d'Afrique Noire. 81: 1-705.

Mooi, R.D. 1993. Phylogeny of the Plesiopidae (Pi-sces: Perciformes) with evidence for the in-clusion of the Canthoclinidae. Bulletin of Marine Science 52: 284-326.

Nasri, N.; Keivany, Y. & Dorafshan, S. 2013. Com-parative Osteology of Lotaks, Cyprinion kais and C. macrostomum (Cypriniformes, Cy-prinidae), from Godarkhosh River, Western Iran. Journal of Ichthyology 53(6): 455–463.

Nelson, J.S.; Grande, T.C & Wilson, M.V.H. 2016. Fishes of the world. 5th edition. John Wiley & Sons, New York, USA. 707p.

Nybelin, O. 1963. Zur morphologie und terminolo-gie des schwanzskelettes der actinopterygier. Arkiv för Zoologi 15: 485-516.

Olney, J.E.; Johnson, G.D. & Baldwin, C.C. 1993. Phylogeny of Lampridiform fishes. Bulletin of Marine Science 52: 137-169.

Orr, J.W. 1995. Phylogenetic relationships of Gas-terosteiform fishes (Teleostei: Acanthomor-pha). PhD thesis. Department of Zoology, University of Washington, Seattle, USA. 813p.

Parenti, L.R. 1981. A phylogenetic and biogeo-graphic analysis of Cyprinodontiform fishes (Teleostei, Atherinomorpha). Bulletin of the American Museum of Natural History 168: 335-557.

Parenti, L.R. 1984. On the relationships of Phallo-stethid fishes (Atherinomorpha), with notes on the anatomy of Phallostethus dunckeri Re-gan, 1913. American Museum Novitates (2779): 1-12.

Parenti, L.R. 1993. Relationships of Atherinomorph fishes (Teleostei). Bulletin of Marine Science 52: 170-196.

Regan, C.T. 1910. The caudal fin of the Elopidae and of some other teleostean fishes. The An-nals & Magazine of Natural History (Zool-ogy) Series 5: 354-358.

Regan, C.T. 1913. The osteology and classification of the teleostean fishes of the order Scleropa-rei. Annual Magazine of Natural History, Se-ries 11: 170-184.

Rojo, A.L. 1991. Dictionary of evolutionary fish os-teology. CRC Press, London, UK.

Rosen, D.E. 1973. Interrelationships of higher eu-teleostean fishes, In Stiassny, M.L.J.; Parenti, L.R. & Johnson, G.D. (eds.). Interrelation-ships of fishes. Academic Press, San Diego, USA. pp: 397-513.

Rosen, D.E. & C. Patterson. 1969. The structure and relationships of the Paracanthopterygian fishes. Bulletin of the American Museum of Natural History 141: 357-474.

Rosen, D.E. & Greenwood, P.H. 1976. A fourth ne-otropical species of synbranchid eel and the phylogeny and systematics of synbranchi-form fishes. Bulletin of the American Mu-seum of Natural History 157: 1-67.

Sasaki, K. 1989. Phylogeny of the family Sciaeni-dae with notes on its zoogeography (Tele-ostei, Perciformes). Memoires of the Faculty of Fisheries, Hokkaido University 36: 1-137.

Schultze, H.P. & Arratia, G. 1989. The composition of the caudal skeleton of teleosts (Actinop-terygii: Osteichthyes). Zoological Journal of the Linnaean Society 97: 189-232.

Shinohara, G. 1994. Comparative morphology and phylogeny of the suborder Hexagrammoidei and related taxa (Pisces: Scorpaeniformes). Memoires of the Faculty of Fisheries, Hok-kaido University 41: 1-97.

Stein, D.L.; Melendez, C.R. & Kong, U.I. 1991. A review of Chilean snailfishes (Liparididae, Scorpaeniformes) with descriptions of a new genus and three new species. Copeia 1991: 358-373.

Stiassny, M.L.J. 1990. Notes on the anatomy and re-lationships of the Bedotiid fishes of Mada-gascar, with a taxonomic revision of the ge-nus Rheocles (Atherinomorpha: Bedotiidae). American Museum Novitates (2979): 1-34.

Stiassny, M.L.J. 1996. Basal ctenosquamate rela-tionships and the interrelationships and the interrelationships of the myctophiform (Scopelomorph) fishes. . In Stiassny, M.L.J.; Parenti, L.R. & Johnson, G.D. (eds.). Interre-lationships of fishes. Academic Press, San Diego, USA. pp: 405-426.

Taylor, W.R. & Van Dyke, G.C. 1985. Revised pro-cedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium 9: 107-119.

Travers, R.A. 1984. A review of the Masta-cembeloidei, a suborder of synbranchiform teleost fishes: part I: anatomical description. Bulletin of British museum of Natural His-tory (Zoology). 46: 1-133.

Westneat, M.W. 1993. Phylogenetic relationships of the tribe Cheilinini (Labridae: Perci-formes). Bulletin of Marine Science 52: 351-394.

Whitehouse, R.H. 1910. The caudal fin of the Tele-ostomi. Proceedings of the Zoological Soci-ety of London 1910: 590-627.

Yabe, M. 1985. Comparative osteology and myol-ogy of the superfamily Cottoidea (Pisces: Scorpaeniformes), and its phylogenetic clas-sification. Memoires of the Faculty of Fisher-ies, Hokkaido University 32: 1-130.

Yabe, M. 1991. Bolinia euryptera, a new genus and species of sculpin (Scorpaeniformes: Cotti-dae) from the Bering Sea. Copeia 1991: 329-339.

Zehren, S.J. 1979. The comparative osteology and phylogeny of the Beryciformes (Pisces: Tele-ostei). Evolutionary Monographs (1): 1-389.


  • There are currently no refbacks.