Glaucostegus

Life-forms

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Classis: Chondrichthyes
Subclassis: Elasmobranchii
Infraclassis: Euselachii
Division/Cohort: Neoselachii
Subdivision/Subcohort: Batoidea
Superordo: Batomorphii
Ordo: Rhinopristiformes

Familia: Glaucostegidae
Genus: Glaucostegus

Species: G. cemiculus – G. granulatus – G. halavi – G. obtusus – G. thouin – G. typus
Name

Glaucostegus Bonaparte, 1846

Type species: Rhinobatus cemiculus Geoffroy Saint-Hilaire, 1817

References

Bonaparte, C.L. 1846. Catalogo metodico dei pesci europei. Atti della Settima Adunanza degli Scienziati Italiani Sesta Riunione, Milano 7a Adunanza, Napoli, Part 2: 1–95. PDF. Reference page.
Last, P.R., Séret, B. & Naylor, G.J.P. 2016. A new species of guitarfish, Rhinobatos borneensis sp. nov. with a redefinition of the family-level classification in the order Rhinopristiformes (Chondrichthyes: Batoidea). Zootaxa 4117(4): 451–475. DOI: 10.11646/zootaxa.4117.4.1. Reference page.

Glaucostegus, also known as giant guitarfishes, is a genus of large Indo-Pacific rays, with a single species, Glaucostegus cemiculus, in the East Atlantic, and Mediterranean.[1] They were formerly classified in the family Rhinobatidae but are now recognized as a distinct family, Glaucostegidae.[2]

Their upperparts are uniform pale yellowish, brownish or greyish, and the nose is pale. Most are large, reaching 1.7–3 m (5.6–9.8 ft) in length depending on the exact species involved, except for the small G. obtusus that is less than 1 m (3.3 ft).[1]
Species

There are ten recognized species, all of which are classified as critically endangered:[2][3]

Glaucostegus cemiculus (Geoffroy St. Hilaire, 1817) (Blackchin guitarfish)
Glaucostegus granulatus Cuvier, 1829 (Sharpnose guitarfish)
Glaucostegus halavi Forsskål, 1775 (Halavi guitarfish)
Glaucostegus microphthalmus (Teng, 1959) (Smalleyed guitarfish)
Glaucostegus obtusus (Müller & Henle, 1841) (Widenose guitarfish)
Glaucostegus petiti (Chabanaud, 1929) (Madagascar guitarfish)
Glaucostegus spinosus (Günther, 1870) (Spiny guitarfish)
Glaucostegus thouin (Anonymous [Lacépède], 1798) (Clubnose guitarfish/Thouin ray)
Glaucostegus typus (E. T. Bennett, 1830) (Giant guitarfish)
Glaucostegus younholeei (Habib & Islam, 2021) (Bangladeshi guitarfish)

References

Last; White; de Carvalho; Séret; Stehmann; Naylor, eds. (2016). Rays of the World. CSIRO. pp. 110–116. ISBN 9780643109148.
Last, P.R.; Séret, B.; Naylor, G.J.P. (2016). "A new species of guitarfish, Rhinobatos borneensis sp. nov. with a redefinition of the family-level classification in the order Rhinopristiformes (Chondrichthyes: Batoidea)". Zootaxa. 4117 (4): 451–475. doi:10.11646/zootaxa.4117.4.1. PMID 27395187.
Froese, Rainer and Pauly, Daniel, eds. (2024). Species of Glaucostegus in FishBase. March 2024 version.