[Artículo Retractado/Retracted Article]:BYCATCH OF HELICOPS ANGULATUS (LINNAEUS 1758) (REPTILIA: SQUAMATA: COLUBRIDAE) IN HOOP-TRAPS USED TO CAPTURE FRESH WATER TURTLES ON THE COAST OF PARÁ, BRAZIL

ABSTRACT Between September, 2007, and August, 2009, six field excursions were conducted on the northern Brazilian coast (Romana and Maiandeua islands, state of Pará) for the collection of specimens of freshwater turtles (Rhinoclemmys punctularia and Kinosternon scorpioides) in natural ponds. Hoop-nets were used and 35 specimens of brown-banded water snakes, Helicops angulatus, were captured as bycatch in the traps. Thus, in addition to turtles, the procedure may be useful for the sampling populations of aquatic snakes. RESUMEN Entre septiembre de 2007 y agosto de 2009, seis excursiones de campo se llevaron a cabo en la costa norte de Brasil (islas Romana y Maiandeua, estado de Pará) para la recolección de especímenes de tortugas de agua dulce (Rhinoclemmys punctularia y Kinosternon scorpioides) en posos naturales. Utilizamos trampas en embudo. 35 ejemplares de la serpiente acuática Helicops angulatus, fueron capturados como pesca incidental en las trampas. Por lo tanto, además de las tortugas, el procedimiento puede ser útil para la toma de muestras de las poblaciones de serpientes acuáticas.

BYCATCH OF Helicops angulatus (LINNAEUS 1758) (REPTILIA: SQUAMATA: COLUBRIDAE) IN HOOP-TRAPS USED TO CAPTURE FRESH WATER TURTLES ON THE COAST OF PARÁ, BRAZIL

Captura accidental de Helicops angulatus (Linnaeus 1758) (Reptilia: Squamata: Colubridae) en trampas en embudo usadas para capturar tortugas dulceacuícolas en la costa de Pará, Brasil

EMIL JOSÉ HERNÁNDEZ-RUZ1, Ph. D.; MANOELA WARISS FIGUEIREDO2, M.Sc.; JUAREZ CARLOS BRITO PEZZUTI2, Ph. D.

1 Laboratório de Zoologia, Faculdade de Ciências Biológicas, Universidade Federal do Pará, Campus de Altamira, Rua Coronel José Porfírio, 2515 - CEP 68.372-040 - Altamira - PA, Brazil. emilhjh@yahoo.com.

2 Núcleo de Altos Estudos Amazônicos, Universidade Federal do Pará/UFPA, Belém, Pará, Brasil. (JCBP) juca@ufpa.br; and (MWF) manuwariss@yahoo.com.br.

Send correspondence to: Emil José Hernández-Ruz, emilhjh@yahoo.com

Received 22 October 2013, first decision 9 November 2013, accepted 19 November 2013.

Citation / Citar este artículo como: HERNÁNDEZ-RUZ EJ, WARISS FIGUEIREDO M, BRITO PEZZUTI JC. Bycatch of Helicops angulatus (Linnaeus 1758) (Reptilia: Squamata: Colubridae) in hoop-traps used to capture fresh water turtles on the Coast of Pará, Brazil. Acta biol. Colomb. 2014. 19(1):121-122.

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ABSTRACT

Between September, 2007, and August, 2009, six field excursions were conducted on the northern Brazilian coast (Romana and Maiandeua islands, state of Pará) for the collection of specimens of freshwater turtles (Rhinoclemmys punctularia and Kinosternon scorpioides) in natural ponds. Hoop trap were used and 35 specimens of brown-banded water snakes, Helicops angulatus, were captured as bycatch in the traps. Thus, in addition to turtles, the procedure may be useful to sample populations of aquatic snakes.

Keywords: Kinosternon scorpioides, natural ponds, Rhinoclemmys punctularia, sampling methods, traps.

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RESUMEN

Entre septiembre de 2007 y agosto de 2009, seis excursiones de campo se llevaron a cabo en la costa norte de Brasil (islas Romana y Maiandeua, estado de Pará) para la recolección de especímenes de tortugas de agua dulce (Rhinoclemmys punctularia y Kinosternon scorpioides) en posos naturales. Utilizamos trampas en embudo. 35 ejemplares de la serpiente acuática Helicops angulatus, fueron capturados como pesca incidental en las trampas. Por lo tanto, además de las tortugas, el procedimiento puede ser útil para la toma de muestras de las poblaciones de serpientes acuáticas.

Palabras clave: Kinosternon scorpioides, métodos de muestreo, pozo de agua, Rhinoclemmys punctularia, trampas de aro.

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Hoop traps are widely used by scientists for the capture of aquatic turtles (Bury, 1979; Fachín-Terán et al., 2003; Fachín- Terán and Vogt, 2004; Rebêlo et al., 2005; Aresco, 2009), in both lotic and lentic systems (Samuel et al., 1976; Dauble, 1986, Muoneke et al., 1993; Hubert, 1996; Tillma et al., 1997; Fratto et al., 2009). However, there are no records of capturing snakes in hoop-traps.

This study was conducted in small, natural ponds on the northern Brazilian coast. One pond was located on Romana Island (00°33'49"S, 47°52'03"W) in Curuça, in the Brazilian state of Pará, and the other at Fortalezinha on Maiandeua Island (00°36'S, 47°32'W), in Maracanã, Pará. The ponds were 0.2-1.7 m deep, with muddy bottoms and abundant aquatic vegetation, primarily in the form of grasses around the pond perimeter. Aquatic macrophytes were common in the Fortalezinha pond.

The primary objective was the capture of freshwater turtles (Rhinoclemmys punctularia Daudin 1801 and Kinosternon scorpioides Linnaeus 1766). 250 mm diameter hoop-traps with a 55-mm mesh and an opening at one end were baited with salted fish (Plagioscion squamosissimus (Heckel, 1840) and Macrodon ancylodon (Bloch and Schneider 1822)), suspended in the center of the hoop. The traps were fixed in the water with a 10 cm gap above the surface which allowed trapped turtles to breathe.

Samples were collected at Fortalezinha on five occasions: twice in the rainy season (between August and December) and three times in the dry season (between September, 2007, and August, 2009), with a total of 94 traps being installed. Seven traps were set at Romana Island in July, 2008. The nets were opened for 48 hours and inspected at 12-hour intervals, totaling 300 trap-hours.

On Romana Island, 30 brown-banded water snakes, Helicops angulatus Linnaeus 1758, were found in the nets. Eleven specimens of both sexes (mean SVL = 504.2 ± 75.8 mm) died in the traps, presumably because of the long interval between trap inspections, which was determined primarily by the distance of the trapping sites from the base camp. Vogt (2001) recommended an inspection interval of every three hours, but the 12-hour interval used in the present study was considered adequate for the trapping of R. punctularia, given that the gap at the top of the trap allowed trapped animals to breathe. This provision did not appear to be totally adequate for the water snakes, because the animals were frequently entangled in net mesh. The specimens were fixed in formalin and deposited in the herpetological collection of the Museu Paraense Emilio Goeldi in Belém, Pará.

At Fortalezinha, five specimens of H. angulatus were captured in the traps.

The other procedure used to trap turtles in the study area - casting nets - did not result in the capture of snakes. The accidental trapping of water snakes in the hoop traps indicates that this may be a useful prodedure for the study of these animals.

ACKNOWLEDGMENT

We thank Roberta Sá Barbosa for assistance in the field, Steve Ferrari for review of manuscript and the Pará State Environment Secretaria for authorizing the study (license number 014/2009).

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