Fatty acid methyl esters extracted from the cuticular surface of Artemia franciscana (Kellogs, 1906) (Crustacea: Anostraca) increase the swim speed of conspecific males

Abstract

Previous researches have established that the swim speed of some microcrustaceans is infl uenced by chemical compounds emitted by conspecifi cs. We examined the hypothesis that cuticular compounds present on the body surface of A. franciscana, the most widespread member of Artemia genus, play a role in the swim speed of conspecifi c males. The movements (swim) of one male confronted to a sponge soaked with female or male cuticular extract, were recorded during 30 minutes and the swim speed was determined using a behavioral tracking software (Ethovision 3.1, Noldus Technologies). As a control, the movements of one male confronted to a sponge soaked with salty water or with a mixture of the solvents used in the extraction (chloroform-methanol), was recorded. The results showed that cuticular compounds from either female or male increase 1.5 (ca.) times the swim speed of males in comparison with the controls treatments salty water and the solvents. There was no a signifi cant difference between the controls (salty water and chloroform-methanol). Chemical characterization was developed by sterifi cation of the cuticular extracts and analyses by GC-FID and GC-MS. Four saturated fatty acid (myristic acid, palmitic acid, estearic acid, arachidic acid) and fi ve insaturated fatty acids (oleic acid, linoleic acid, linoleic acid 3n3, cis-11-eicosanoic acid, euric acid) were identifi ed. Myristic acid was found in female cuticular extract, but not in male cuticular extract. Results suggest that chemical compounds present in the cuticular surface of A. franciscana females could have an important role in the intra-specifi c recognition in this specie. KEYWORDS:Artemia, swimming speed, cuticular compounds, fatty acids, chemical communication. RESUMENInvestigaciones anteriores han establecido que la velocidad de nado de algunos microcrustáceos se encuentra infl uenciada por compuestos químicos emitidos por conespecífi cos. Nosotros examinamos la hipótesis de que los compuestos cuticulares presentes sobre la superfi cie corporal de A. franciscana, el miembro con mayor distribución mundial del genero Artemia, juega un rol en la velocidad de nado de machos conespecífi cos. Los movimientos nado de un macho confrontado a una esponja empapada con extracto cuticular de una hembra o de un macho, fueron grabados durante 30 minutos y la velocidad de nado fue determinada usando un software de rastreo conductual (Ethovision 3.1, Noldus Technologies). Como control, fueron grabados los movimientos de un macho confrontado a una esponja empapada con agua de mar artifi cial o con una mezcla de los solventes usados en la extracción (cloroformo-metanol). Los resultados mostraron que los compuestos cuticulares tanto de hembras como de machos incrementan 1,5 veces (aproximadamente) la velocidad de nado de los machos, en comparación con los experimentos control donde se uso agua de mar artifi cial y los solventes de la extracción. No hubo diferencias signifi cativas entre los controles (agua de mar artifi cial y cloroformo-metanol). La cara...

Fatty Acid Composition in Cultured Amphiascoides neglectus (Copepoda: Harpacticoida)

“…EFAs are crucial in stabilizing a healthy ecosystem and are primary source of natural availability of EFA [24]. Other fatty acids also play important rule, such as those in the exoskeleton which could give the intra-specific recognition in Artemia species [25]. The low concentration of several FA found in this study could possibly relate to the diet, in this study all harpacticoids were having yeast as their diet which is known for the low nutrient content if compared to microalgal diet [26].…”