RESUMO
The largemouth bass Micropterus salmoides is a very valuable fish species for aquaculture and sport fishing; however, there are no systematic studies on fish metazoan parasites in Mexico. The main objective of the present study was to describe the prevalence, abundance, and intensity of M. salmoides metazoan parasites, and their association with fish condition factor and gender. The sample size was composed by 672 hosts, collected between 2011-2013 from the following reservoirs of Nuevo Leon, México: Rodrigo Gómez dam ("La Boca", LB), Cuchillo-Solidaridad dam (CS), Salinillas lagoon (LS), Mariano Escobedo dam ("Sombreretillo", S), and José López Portillo dam ("Cerro Prieto", CP). Living fish were transported to the laboratory; sizes and weights were then recorded to calculate the Fulton condition factor (k). If possible, gender was also recorded. Parasites were detected under stereoscopy, recollected and preserved by traditional techniques. Statistical analysis of association between parasitic load, gender, and Fulton condition factor were calculated, using the X2 and the Student-t tests. Results showed that 12 different metazoans were identified, two flukes (Posthodiplostomum minimum centrarchi and Phyllodistomum pearsei), one tapeworm (Proteocephalus ambloplitis), three roundworms (Contracaecum sp., Spinitectus carolini and Philometra nodulosa), two acantocephalan (Neoechinorhynchus cylindratus and Arhythmorhynchus sp.), one leech (Myzobdella moorei), and three copepods (Ergasilus versicolor; Ergasilus arthrosis and Ergasilus cerastes). HSD Tukey test showed that infected fish from LB were significantly different than LS, CS, CP, and S (P<0.05). Parasites most commonly collected in all five locations were P. m. centrarchi, Contracaecum sp. and E. versicolor. The frequency of P. m. centrarchi was highly significant (P<0.001) than other parasites; furthermore, this parasite showed the highest prevalence (97.5 %), abundance (10.12-83.6), and intensity (15.44-88.5). Statistical dependence was found between intensity and abundance of metazoans with regard to female gender and size on five reservoirs (t=143.82, P=0.0001; t=2.6, P=0.01, respectively). In addition, the abundance and intensity showed statistical dependence with regard to k, which was proportionally significant. New locality records for Nuevo Leon include P. m. centrarchi, P. pearsei, P. ambloplitis, Contracaecum sp., Arhythmorhynchus sp., and E. cerastes. Furthermore, P. nodulosa, S. carolini, N. cylindratus, and E. arthrosis were new records for Mexico.
Assuntos
Doenças dos Peixes/parasitologia , Parasitos/classificação , Doenças Parasitárias em Animais/parasitologia , Perciformes/parasitologia , Animais , Aquicultura , Feminino , Masculino , México , Parasitos/isolamento & purificação , Fatores SexuaisRESUMO
ResumenMicropterus salmoides es una especie muy apreciada en la acuacultura y pesca deportiva, sin embargo, no existen estudios sistemáticos sobre los parásitos en México. El objetivo principal del presente estudio fue describir la prevalencia, abundancia e intensidad de los metazoarios parásitos de M. salmoides y su asociación con el factor de condición y el sexo. El tamaño de muestra fue de 672 hospederos, recolectados entre 2011-2013 de los siguientes reservorios de Nuevo León, México: Presa Rodrigo Gómez (“La Boca”, LB); Presa Cuchillo-Solidaridad (CS), Laguna Salinillas (LS), Presa Mariano Escobedo (“Sombreretillo”, S), y Presa José López Portillo (“Cerro Prieto”, CP). Los peces fueron transportados vivos al laboratorio, se les registró el tamaño y peso para calcular el coeficiente de condición de Fulton (k). El sexo también se registró cuando fue posible. Los parásitos fueron detectados con el estereoscopio, recolectados y preservados con las técnicas parasitológicas tradicionales. Se calcularon los análisis estadísticos de asociación entre la carga parasitaria, sexo y factor de condición usando X2 y la prueba de t de Student. Los resultados mostraron la identificación de 12 metazoarios diferentes: dos tremátodos (Posthodiplostomum minimum centrarchi y Phyllodistomum pearsei); un céstodo (Proteocephalus ambloplitis); tres nemátodos (Contracaecum sp.; Spinitectus carolini y Philometra nodulosa); dos acantocéfalos (Neoechinorhynchus cylindratus y Arhythmorhynchus sp.); un hirudineo (Myzobdella moorei) y tres copépodos (Ergasilus versicolor; Ergasilus arthrosis y Ergasilus cerastes). La prueba de Tukey HSD mostró que los peces infectados de LB fueron significativamente diferentes a los de LS, CS, CP y S (P < 0.05). Los parásitos que se recolectaron más comúnmente en las cinco localidades fueron: P. m. centrarchi, Contracaecum sp., y E. versicolor. La frecuencia de P. m. centrarchi fue altamente significativa (P < 0.001) en comparación con los otros parásitos; además presentó la más elevada prevalencia (97.5 %), abundancia (10.12-83.6) e intensidad (15.4488.5). Se encontró asociación estadística entre la intensidad y abundancia de los metazoarios con respecto al sexo femenino y tamaño en los cinco reservorios (t= 143.82, P = 0.0001; t= 2.6, P= 0.01, respectivamente). Además, la abundancia e intensidad mostraron asociación estadística con respecto a k, lo cual fue proporcionalmente significativo. Se incluyen nuevos registros de localidad para P. m. centrarchi, P. pearsei, P. ambloplitis, Contracaecum sp., Arhythmorhynchus sp. y E. cerastes. Además, P. nodulosa, S. carolini, N. cylindratus, y E. arthrosis se consideran como nuevos registros para México.
AbstractThe largemouth bass Micropterus salmoides is a very valuable fish species for aquaculture and sport fishing; however, there are no systematic studies on fish metazoan parasites in Mexico. The main objective of the present study was to describe the prevalence, abundance, and intensity of M. salmoides metazoan parasites, and their association with fish condition factor and gender. The sample size was composed by 672 hosts, collected between 2011-2013 from the following reservoirs of Nuevo Leon, México: Rodrigo Gómez dam (“La Boca”, LB), Cuchillo-Solidaridad dam (CS), Salinillas lagoon (LS), Mariano Escobedo dam (“Sombreretillo”, S), and José López Portillo dam (“Cerro Prieto”, CP). Living fish were transported to the laboratory; sizes and weights were then recorded to calculate the Fulton condition factor (k). If possible, gender was also recorded. Parasites were detected under stereoscopy, recollected and preserved by traditional techniques. Statistical analysis of association between parasitic load, gender, and Fulton condition factor were calculated, using the X2 and the Student-t tests. Results showed that 12 different metazoans were identified, two flukes (Posthodiplostomum minimum centrarchi and Phyllodistomum pearsei), one tapeworm (Proteocephalus ambloplitis), three roundworms (Contracaecum sp., Spinitectus carolini and Philometra nodulosa), two acantocephalan (Neoechinorhynchus cylindratus and Arhythmorhynchus sp.), one leech (Myzobdella moorei), and three copepods (Ergasilus versicolor; Ergasilus arthrosis and Ergasilus cerastes). HSD Tukey test showed that infected fish from LB were significantly different than LS, CS, CP, and S (P<0.05). Parasites most commonly collected in all five locations were P. m. centrarchi, Contracaecum sp. and E. versicolor. The frequency of P. m. centrarchi was highly significant (P<0.001) than other parasites; furthermore, this parasite showed the highest prevalence (97.5 %), abundance (10.12-83.6), and intensity (15.44-88.5). Statistical dependence was found between intensity and abundance of metazoans with regard to female gender and size on five reservoirs (t=143.82, P=0.0001; t=2.6, P=0.01, respectively). In addition, the abundance and intensity showed statistical dependence with regard to k, which was proportionally significant. New locality records for Nuevo Leon include P. m. centrarchi, P. pearsei, P. ambloplitis,Contracaecum sp., Arhythmorhynchus sp., and E. cerastes. Furthermore, P. nodulosa, S. carolini, N. cylindratus, and E. arthrosis were new records for Mexico. Rev. Biol. Trop. 64 (2): 559-569. Epub 2016 June 01.