Gempylidae Explained

The Gempylidae are a family of scombriform ray-finned fishes commonly known as snake mackerels or escolars. The family includes about 25 species.

They are elongated fishes with a similar appearance to barracudas, having a long dorsal fin, usually with one or finlets trailing it. The largest species, including the snoek (Thyrsites atun), grow up to 2 m long, and the oilfish (Ruvettus pretiosus) can reach 3 m, though they rarely surpass 150 cm. Like the barracudas, they are predators, with fang-like teeth.^[1]

Taxonomy

• Subfamily Clade 1 Mthethwa, 2023
  • Genus Diplospinus
    • Diplospinus multistriatus Maul, 1948 (Striped escolar)
  • Genus Gempylus
    • Gempylus serpens G. Cuvier, 1829 (Snake mackerel)
  • Genus Nealotus
    • Nealotus tripes J. Y. Johnson, 1865 (Black Snake mackerel)
  • Genus Nesiarchus
    • Nesiarchus nasutus J. Y. Johnson, 1862 (Black gemfish)
  • Genus Paradiplospinus
    • Paradiplospinus antarcticus Andriashev, 1960 (Antarctic escolar)
    • Paradiplospinus gracilis (A. B. Brauer, 1906) (Slender escolar)
  • Genus Promethichthys
    • Promethichthys prometheus (G. Cuvier, 1832) (Roudi escolar)
  • Genus Rexea
    • Rexea alisae C. D. Roberts & A. L. Stewart, 1997
    • Rexea antefurcata Parin, 1989 (Long-finned escolar)
    • Rexea bengalensis (Alcock, 1894) (Bengal escolar)
    • Rexea brevilineata Parin, 1989 (Short-lined escolar)
    • Rexea nakamurai Parin, 1989 (Nakamura's escolar)
    • Rexea prometheoides (Bleeker, 1856) (Royal escolar)
    • Rexea solandri (G. Cuvier, 1832) (Silver gemfish)
  • Genus Rexichthys
    • Rexichthys johnpaxtoni Parin & Astakhov, 1987 (Paxton’s escolar)
  • Genus Thyrsites
    • Thyrsites atun (Euphrasén, 1791) (Snoek)
  • Genus Thyrsitoides
    • Thyrsitoides marleyi Fowler, 1929 (Blacksail snake mackerel)
  • Genus Thyrsitops
    • Thyrsitops lepidopoides (G. Cuvier, 1832) (White Snake Mackerel)
  • Genus Tongaichthys
    • Tongaichthys robustus I. Nakamura & E. Fujii, 1983 (Tonga escolar)
• Subfamily Clade 2 Mthethwa, 2023
  • Genus Epinnula
    • Epinnula magistralis Poey, 1854
    • Epinnula pacifica Ho, Motomura, Hata & Jiang, 2017
  • Genus Lepidocybium
    • Lepidocybium flavobrunneum (A. Smith, 1843) (Escolar)
  • Genus Neoepinnula
    • Neoepinnula americana (M. G. Grey, 1953) (American sackfish)
    • Neoepinnula minetomai Nakayama, Y. Kimura & Endo, 2014 (Large-eyed sackfish)
    • Neoepinnula orientalis (Gilchrist & von Bonde, 1924) (Sackfish)
  • Genus Ruvettus
    • Ruvettus pretiosus Cocco, 1833 (Oilfish)

The Gempylidae are broadly categorized into two clades; Clade 1, which includes more derived & elongate genera, and Clade 2, which includes more basal & fusiform genera. The Trichiuridae are an outgroup.^[2]

Gempylidae are believed to have first evolved at least 20 million years after the Late Cretaceus Extinction event, potentially due to tectonic plate movements.

Timeline

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^[3]

See also

• Euzaphlegidae, an extinct group of relatives from Paleocene to Late Miocene-aged marine strata of Europe, the Caucasus Mountains,^[4] India, Iran, Turkmenistan, Italy,^[5] and Southern California.^[6]

External links

• Sepkoski . Jack . A compendium of fossil marine animal genera . Bulletins of American Paleontology . 364 . 560 . 2002 . 2011-05-19 . dead . https://web.archive.org/web/20110723131237/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class . July 23, 2011 .
• Scientia Marina - Population biology of the roudi escolar Promethichthys prometheus (Gempylidae) off the Canary Islands
• Deep water fish species - Lanzarote

Notes and References

1. Book: Paxton, J.R. . Eschmeyer, W.N.. Johnson, G.D. . Gill, A.C.. 1998. Encyclopedia of Fishes. Academic Press. San Diego. 0-12-547665-5. 190.
2. Mthethwa . Siphesihle . Bester-van_der_Merwe . Aletta E. . Roodt-Wilding . Rouvay . June 2023 . Addressing the complex phylogenetic relationship of the Gempylidae fishes using mitogenome data . Ecology and Evolution . en . 13 . 6 . e10217 . 10.1002/ece3.10217 . 2045-7758 . 10283032 . 37351481. 2023EcoEv..1310217M .
3. Rust . Seabourne . Robinson . Jeffrey H. . 2023-07-12 . Revisiting Eothyrsites holosquamatus Chapman (Trichiuroidea: Gempylidae), an Eocene gemfish from the Burnside Mudstone, Dunedin, New Zealand . Journal of the Royal Society of New Zealand . 54 . 5 . 584–601 . 10.1080/03036758.2023.2228211 . 0303-6758. free . 11459795 .
4. Danilʹchenko, P. G. (1967). Bony fishes of the Maikop deposits of the Caucasus.
5. Bannikov, Alexandre F. (2008). "A new genus and species of putative euzaphlegid fish from the Eocene of Bolca in northern Italy (Periformes, Trichiuroidea)." Studi e Ricerche sui giacimenti Terziari di Bolca, XII Miscellanea Paleontologica 9: 99–107. https://www.researchgate.net/profile/A_Bannikov/publication/257932455_A_NEW_GENUS_AND_SPECIES_OF_PUTATIVE_EUZAPHLEGID_FISH_FROM_THE_EOCENE_OF_BOLCA_IN_NORTHERN_ITALY_(PERCIFORMES_TRICHIUROIDEA)/links/0deec53c7b3e61e6c1000000.pdf
6. David, Lore Rose (January 10, 1943). Miocene Fishes of Southern California. Geological Society of America. pp. 104–115.