Use of eugenol for anesthesia of lesser guitarfish Zapteryx brevirostris (Rhinobatidae) / Uso de eugenol para anestesia de raia-viola Zapteryx brevirostris (Rhinobatidae)

Anesthesia can be utilized as a non-lethal procedure to allow easy handling of teleosts and elasmobranchs in captivity or in the wild. For this, anesthetic protocols need to be established according to the species. The aim of this study was to determine the ideal concentration of eugenol for anesthesia of Zapteryx brevirostris. Four concentrations were tested: 21.25, 42.50, 85.00 and 170.00 mg L-1 (ratio of 1:5 with absolute ethanol). The perfect concentration of eugenol for this species was 85.0 mg L-1 , which enabled up to 300 seconds of work on the fish, without any response to handling.(AU)

A anestesia pode ser utilizada como um procedimento não letal que facilita o manejo de teleósteos e elasmobrânquios de cativeiro e de vida livre. Para isso, protocolos anestésicos devem ser estabelecidos de acordo com a espécie. O objetivo deste trabalho foi determinar a concentração ideal do eugenol para anestesiar Zapteryx brevirostris. Foram testadas as concentrações de 21,25; 42,50; 85,00 e 170,00 mg L-1 (1:5 de álcool absoluto). A concentração de 85,0 mg L-1 de eugenol foi a mais adequada para a espécie, permitindo uma janela de trabalho de até trezentos segundos com o animal não respondendo ao manejo.(AU)

Use of eugenol for anesthesia of lesser guitarfish Zapteryx brevirostris (Rhinobatidae)

Abstract Anesthesia can be utilized as a non-lethal procedure to allow easy handling of teleosts and elasmobranchs in captivity or in the wild. For this, anesthetic protocols need to be established according to the species. The aim of this study was to determine the ideal concentration of eugenol for anesthesia of Zapteryx brevirostris. Four concentrations were tested: 21.25, 42.50, 85.00 and 170.00 mg L-1 (ratio of 1:5 with absolute ethanol). The perfect concentration of eugenol for this species was 85.0 mg L-1 , which enabled up to 300 seconds of work on the fish, without any response to handling.

Resumo A anestesia pode ser utilizada como um procedimento não letal que facilita o manejo de teleósteos e elasmobrânquios de cativeiro e de vida livre. Para isso, protocolos anestésicos devem ser estabelecidos de acordo com a espécie. O objetivo deste trabalho foi determinar a concentração ideal do eugenol para anestesiar Zapteryx brevirostris. Foram testadas as concentrações de 21,25; 42,50; 85,00 e 170,00 mg L-1 (1:5 de álcool absoluto). A concentração de 85,0 mg L-1 de eugenol foi a mais adequada para a espécie, permitindo uma janela de trabalho de até trezentos segundos com o animal não respondendo ao manejo.

Occurrence of Metacaligus rufus (Wilson, 1908) (Copepoda, Caligidae) parasitizing the cownose ray Rhinoptera bonasus (Mitchill, 1815) (Elasmobranchii, Myliobatidae) in Brazil

The family Caligidae are predominantly external parasites of fishes, inhabiting the outer surface, the mouth, the gills and opercular cavity of their hosts (Boxshall and Halsey, 2004). This family comprises one of the most speciose group within the Copepoda, currently encompassing 31 genera, including Metacaligus (Thomsen, 1949) which consistis of five nominal species (Walter and Boxshall, 2008). Members of Metacaligus have been associated with actinopterygian fishes or obtained from plankton, particularly from American and Asian waters (Ho and Bashirullah, 1977; Suárez-Morales et al., 2012). In the seaboard of Brazil, two species have been hitherto recorded, i.e., Metacaligus rufus (Wilson, 1908) from the gills of Merluccius sp., Oligoplites palometa (Cuvier, 1832), O. saliens (Bloch, 1793), Scomberomorus sp., Selene vomer (Linnaeus, 1758), Trichiurus lepturus (Linnaeus, 1758) and Umbrina sp.; and M. trichiuri (Krøyer, 1863) from the gills of T. lepturus (Luque and Tavares, 2007; Luque et al., 2013). The Cownose ray Rhinoptera bonasus (Mitchill, 1815) (Myliobatidae) is an oceanic species found occasionally in sandy bottoms near the coast, feeding a variety number of bivalve mollusks and other benthic prey (Figueiredo, 1977; Froese and Pauly, 2016). This species is widely distributed in the Atlantic Ocean, found in the Western Atlantic: northern Florida (USA), throughout the Gulf of Mexico to south Brazil; and in the Eastern Atlantic: Mauritania, Senegal and Guinea (Froese and Pauly, 2016). Among the species of genus Rhinoptera, The International Union for Conservation of Nature (IUCN) listed this species as Near Threatened (NT) in relation to the state of conservation (Froese and Pauly, 2016; International Union for Conservation of Nature and Natural Resources, 2016).(AU)

Use of eugenol for anesthesia of lesser guitarfish Zapteryx brevirostris (Rhinobatidae)

Abstract Anesthesia can be utilized as a non-lethal procedure to allow easy handling of teleosts and elasmobranchs in captivity or in the wild. For this, anesthetic protocols need to be established according to the species. The aim of this study was to determine the ideal concentration of eugenol for anesthesia of Zapteryx brevirostris. Four concentrations were tested: 21.25, 42.50, 85.00 and 170.00 mg L-1 (ratio of 1:5 with absolute ethanol). The perfect concentration of eugenol for this species was 85.0 mg L-1 , which enabled up to 300 seconds of work on the fish, without any response to handling.

Resumo A anestesia pode ser utilizada como um procedimento não letal que facilita o manejo de teleósteos e elasmobrânquios de cativeiro e de vida livre. Para isso, protocolos anestésicos devem ser estabelecidos de acordo com a espécie. O objetivo deste trabalho foi determinar a concentração ideal do eugenol para anestesiar Zapteryx brevirostris. Foram testadas as concentrações de 21,25; 42,50; 85,00 e 170,00 mg L-1 (1:5 de álcool absoluto). A concentração de 85,0 mg L-1 de eugenol foi a mais adequada para a espécie, permitindo uma janela de trabalho de até trezentos segundos com o animal não respondendo ao manejo.