Family Gymnuridae The Butterfly Rays Greek, gymnos = naked + Greek,tai = tail

Descriptive Features Skin relatively smooth with small denticles Broad, diamond shaped ray DW is almost 2x TL Short tail Some with poisonous tail spine Dorsal fin present or absent

Tooth Morphology

Order Myliobatiformes

Taxonomy 12-14 species in 2 genera Aetoplata A. zonura – Zonetail A. tentaculata – Tentacled Gymnura G. australis - Australian G. natalensis – Backwater G. micrura – Smooth G. altavela – Spiny G. japonica – Japanese G. poecilura – Long-tail G. hirundo – Madiera (? validity) G. bimaculata – Twin-spot G. crooki G. marmorata – California G. crebripunctata – Long snout G. afuerae

Gymnura debate G. marmorata G. afuerae G. crebripunctata Gulf of California to Peru

Gymnura altavela over 4m wingspan (>13ft) Largest Gymnura Gymnura altavela over 4m wingspan (>13ft)

Found in the Atlantic, Pacific, and Indian Oceans Distribution Found in the Atlantic, Pacific, and Indian Oceans

Habitat Marine, rarely brackish Tropical to temperate Continental shelves Demersal, benthic Depths range from intertidal to100m Prefers sandy and muddy substrates Also found in brackish estuaries, hyper-saline lagoons, coastal and neritic waters, bays, sandy beaches, and salt marshes

Diet Teleosts Crustaceans Mollusks Plankton Polychaetes Benthic copepods, crabs, shrimps, prawns Mollusks Bivalves, cephalopods, gastropods Plankton Polychaetes

Predators Marine mammals Hammerhead sharks Larger fishes

Reproduction Two functional uteri Aplacental viviparous Embryos initially fed with yolk, then uterine milk Gestation ~4-9 months One reproductive cycle per year Fecundity assumed to be <10 Females commonly abort fetuses upon capture (G. poecilura)

Status IUCN status Population doubling time >14 years 9 spp not in IUCN 3 spp data deficient 1 sp vulnerable – A. zonura (declines of at least 30%) 1 sp near threatened – G. poecilura Population doubling time >14 years

Major Threats Bycatch (shrimp trawlers) Low recruitment/reproduction High juvenile mortality Habitat degradation and loss Harvested for food Food trade

Literature Cited Bauchot, M.-L., 1987. Raies et autres batoides. p. 845-886. In W. Fischer, M.L. Bauchot and M. Schneider (eds.) Fiches FAO d'identificationpour les besoins de la pêche. (rev. 1). Mèditerranée et mer Noire. Zone de pêche 37. Vol. II. Commission des Communautés Européennes and FAO, Rome.  Bizzarro, J.J. & White, W.T. 2006. Gymnura poecilura. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 28 November 2007. Compagno, L.J.V., 1999. Checklist of living elasmobranchs. p. 471-498. In W.C. Hamlett (ed.) Sharks, skates, and rays: the biology of elasmobranch fishes. John Hopkins University Press, Maryland.  Grubbs, R.D. & Ha, D.S. 2006. Gymnura micrura. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 28 November 2007. Last, P.R. and J.D. Stevens, 1994. Sharks and rays of Australia. CSIRO, Australia. 513 p.  McEachran, J.D. and B. Seret, 1990. Gymnuridae. p. 64-66. In J.C. Quero, J.C. Hureau, C. Karrer, A. Post and L. Saldanha (eds.) Check-list of the fishes of the eastern tropical Atlantic (CLOFETA). JNICT, Lisbon; SEI, Paris; and UNESCO, Paris. Vol. 1.  Nelson, J.S. 2006. Fishes of the World, 4th ed. John Wiley and Sons, Inc, NJ. p 80. Smith, W.D. & Bizzarro, J.J. 2006. Gymnura marmorata. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 28 November 2007. White, W.T. 2006. Aetoplatea zonura. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 28 November 2007. Wintner, S.P. 2006. Gymnura natalensis. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 28 November 2007. Gonzalez-Isais, M and Domı´nguez, HMM. 2004. Comparative Anatomy of the Superfamily Myliobatoidea (Chondrichthyes) With Some Comments on Phylogeny. JOURNAL OF MORPHOLOGY 262:517–535.