Trophic ecology of Mugil liza at the southern limit of its distribution (Buenos Aires, Argentina)

Abstract

In order to get to know the habitat and feeding habits of Mugil liza on the southern coast of Buenos Aires province, 65 specimens obtained at two sampling sites - the San Blas bay (SBB) and the mouth of the Quequén-Salado river (QSR) - during spring (November 2012) and summer (February 2013) were analyzed. Specimens were measured, sexed and weighed, their stomachs were removed and their stomach contents weighed and analyzed under the stereoscopic microscope. The specimens were adults, 28-49 cm in length and weighing 380-1100 g. Population growth was higher in the SBB (TW: 0.003*TL3.36), than in RQS (TW: 0.045*TL2.61). About 98% of the stomachs had some content, their repletion rate being of between 0.4 and 1.2%. About 75% of the stomachs contained very fine sand with few benthic organisms (algae, copepods, foraminifera), whereas the remaining 25% of stomachs contained coarse sand and a greater presence of benthic fauna (amphipods, bivalves, gastropods and coral organisms). The linear relationship between the weight of stomach contents and the total weight and length of the fish showed that the rates of growth (slope) were the same at both sites, but intercept values were significantly higher for San Blas bay (test parallelism; p < 0.001).

Unravelling Stock Spatial Structure of Silverside Odontesthes argentinensis (Valenciennes, 1835) from the North Argentinian Coast by Otoliths Shape Analysis

“…Marine and euryhaline coastal species inhabit dynamic environments so they generally show high plasticity [56], such as atherinids, mugilids and sardines [17,37,[57][58][59]. This plasticity can be reflected in otoliths.…”

Variación de los hábitos tróficos en nueve especies de peces de la Laguna Garzón (Uruguay)

“…Esta especie M. liza se ha definido como iliófaga, detritívora y capaz de ingerir mayormente diatomeas (Olivera y Soares 1996;Claudino, et al, 2013), y, en consecuencia, caracterizada con una posición trófica de consumidor primario, tal como se ha encontrado en organismos juveniles de M. liza en este trabajo. Pequeños organismos asociados al sedimento como microcrustáceos, anfípodos, bivalvos y gasterópodos también han sido reportados en la dieta de M. liza, en línea con los resultados isotópicos obtenidos en este trabajo (Thompson, et al, 2015). Las fuentes de materia orgánica colectadas en la Laguna Garzón incluyeron el MOP en suspensión (el cual integra al material vivo del fitoplancton y al detritus), MOS y plantas vasculares.…”

Inflammatory reaction induced by Floridosentis mugilis (Acanthocephala, Neoechinorhynchidae) in the intestine of Mugil liza

“…When the intermediate hosts are ingested by the fish (definitive host), the larvae excyst, attach to the intestinal wall and becomes sexually mature (Kennedy 2006;Rosas-Valdez, Morrone, and García-Varela 2012). The feeding studies of juveniles and subadults of M. liza within the Argentine territory recorded by Jerez and Christiansen (1987), Acha (1990) and Thompson et al (2015) indicated the presence of benthic diatoms, dinoflagellates and metazoans, mainly copepods and amphipods in the stomach content. No changes in the diet were observed with the body size.…”