Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida) to potassium dichromate and sediment particle size

Abstract

A B S T R A C TFor the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil), sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any detrimental biological effects on benthic invertebrates. Neither survival nor fecundity was affected by grain size, suggesting that this species can be used with any kind of sediment from muddy to sandy. The sensitivity of T. biminiensis to K 2 Cr 2 O 7 in acute tests was similar to that of other organisms. The LC 50 (lethal concentration to 50% of the test organisms) medium values for T. biminiensis were 7.51, 4.68 and 3.19 mg L -1 for Cr in 48, 72 and 96 h, respectively. These results suggest that T. biminiensis is a promising organism for use in solid-phase sediment toxicity assessments. R E S U M OVisando o uso futuro do copépodo marinho bentônico Tisbe biminiensis em bioensaios toxicológicos de sedimentos na fase sólida, o presente estudo investigou o efeito do sedimento lamoso do estuário de Maracaípe (Nordeste do Brasil). Foram considerados a granolometria e o tóxico de referência dicromato de potássio sobre a espécie. O sedimento lamoso de Maracaípe pode ser usado como controle, uma vez que não interfere no ciclo de vida do copépodo e possui níveis de contaminação de metais que não causariam efeitos biológicos em invertebrados bentônicos. Nem a sobrevivência ou fecundidade foi afetada pelo tamanho do grão, sugerindo que esta espécie pode ser usada com qualquer tipo de sedimento, de lama a areia. A sensibilidade de T. biminiensis ao K 2 Cr 2 O 7 em testes agudos foi similar a de outros organismos. Os valores de CL 50 (concentração letal a 50% dos organismos) para T. biminiensis foram em média 7,51, 4,68 e 3,19 mg L -1 para o Cr em 48, 72 e 96h, respectivamente. Estes resultados sugerem que T. biminiensis é um organismo promissor para uso em avaliações de toxicidade com a fase sólida do sedimento.

Is meiofauna community structure in Artificial Substrate Units a good tool to assess anthropogenic impact in estuaries?

“…This estuary has a well-preserved mangrove vegetation far from urban centres (Araújo-Castro et al, 2009), although tourism has increased in the last several decades and is the major threat to local biodiversity (CPRH, 2006). The Santa Cruz Channel is an estuarine complex (sampling point on 7°46′11.04″S and 34°52′55.56″W) located in the northern coast of Pernambuco.…”

Acute Sensitivity to Nitokra sp Benthic Copepod to Potassium Dichromate and Ammonia Chloride

“…In regard to other crustaceans, Nitokra sp showed more tolerance to potassium dichromate than Tiburonella viscana (Abessa & Sousa, 2003) and the harpacticoid copepod Tisbe biminiensis (Araújo-Castro et al, 2009). The measure of sensitivity between each species to potassium dichromate through the LC 50 rates is expressed in Table 4.…”

The use of epibenthic copepod Tisbe biminiensis nauplii to assess the toxicity of seawater samples in Suape Bay (state of Pernambuco; Brazil)

“…This epibenthic copepod species originally sampled from the city of Olinda (state of Pernambuco, Brazil) has been reared in the laboratory for many generations since 1998 and has a well-studied life cycle (Pinto et al, 2001;Souza-Santos et al, 2006;Ribeiro & Souza-Santos, 2011). Adult females of this species were successfully used as test organisms to assess estuarine sediment quality (Araújo-Castro, 2008;Araújo-Castro et al, 2009). Lavorante et al (2013) proposed a novel, simple protocol using T. biminiensis nauplii as test organisms for seawater samples, but did not test the method using environmental samples or compare their results to any another established protocol, as was done in the present study.…”

“…The ASTM E-2317-04 protocol was also developed for ecotoxicity tests on the complete life cycle of the copepod Amphiascus tenuiremis in 96-well microplates (ASTM, 2004). The female harpacticoid copepod Tisbe biminiensis Volkman-Rocco (1973) has been successfully used in toxicity tests with sediments since 2003 (Araújo-Castro, 2008;Araújo-Castro et al, 2009). Recently, Lavorante et al (2013) proposed a novel, simple ecotoxicological protocol for seawater samples using T. biminiensis nauplii.…”