Diet Composition and Feeding Strategy of the New World SilversideOdontesthes argentinensisin a Temperate Coastal Area (South America)

Abstract

The diet composition and feeding strategy of the New World silverside Odontesthes argentinensis were evaluated in a temperate coastal area during austral summer. This species is an economically significant resource for the fishing industry in South America. The food preference of O. argentinensis varied with its size‐class: the smallest size‐classes preferred diatoms and annelids, larger size‐classes seemed to prefer barnacle cypris larvae, and the largest size‐classes showed a preference for decapod megalopa larvae. Plankton samples were dominated by calanoid and cyclopoid copepods; however, contrary to what was expected, O. argentinensis showed negative selectivity for both groups. A selectivity index indicated that O. argentinensis selects the food it eats with regard to prey availability in the environment. The information obtained in this study demonstrates the importance of knowing the food preference of O. argentinensis to obtain a better condition factor, which will be key to its potential farming in closed systems.

Length-weight and length-length relationship for three marine fish species of commercial importance from southwestern Atlantic Ocean coast

“…1). Isometric growth registered for O. argentinensis agreed with the recorded data reported by Thompson & Volpedo (2018) in the same place but only with summer samples. Other reports for this species from Brazil (Haimovici & Velasco, 2000), Uruguay (Gurdek & Acuña, 2014), and Argentina (Molina, 2012;Llompart et al, 2013) suggested positive allometric growths.…”

Application of otolith morphometry for the study of ontogenetic variations of Odontesthes argentinensis

“…On the other hand, Hüssy (2008), suggests that the overall shape of the otolith is an ontogenetic process, while the finer details can be modulated by environmental conditions, most particularly related with feeding level, ranging from starvation to ad libitum (Gagliano and McCormick 2004) and food availability (Cardinale et al 2004). In this sense, the observed changes in stage I, could be due to the fact that the fish have greater swimming habits and feed on plankton (Thompson and Volpedo 2018). In stage II fish broaden their range of prey items by feeding on other organisms associated with the bottom such as Tanaidacea, Polychaeta, Amphipoda and megalopa stage of Crustacea Decapoda larvae (Bemvenuti 1990;Martinetto et al 2005;Thompson and Volpedo 2018) and these changes in the diet could be reflected in otoliths shape.…”

“…In this sense, the observed changes in stage I, could be due to the fact that the fish have greater swimming habits and feed on plankton (Thompson and Volpedo 2018). In stage II fish broaden their range of prey items by feeding on other organisms associated with the bottom such as Tanaidacea, Polychaeta, Amphipoda and megalopa stage of Crustacea Decapoda larvae (Bemvenuti 1990;Martinetto et al 2005;Thompson and Volpedo 2018) and these changes in the diet could be reflected in otoliths shape. On the other hand, stage III includes individuals with the size of first sexual maturation (Bemvenuti 1990;Tombari et al 2005;Llompart et al 2013), thus, otolith changes could be associated with displacement habits (de Carvalho et al 2015;Callicó Fortunato et al 2017).…”

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

“…Atherinopsids are an important group of coastal fishes for artisanal and/or recreational fisheries, and have a great inter-population phenotypic plasticity, presenting morphological, morphometric and meristic differences along the marine coast [18][19][20][21] and in continental environments [22][23][24]. Due to its complexity, this group has been studied in different aspects of its biological cycle, but very few authors have established the identification of stocks of this group [14,18,25,26], and even less so in marine atherinids.…”