The mullet Mugil liza is the Mugilidae that lives southernmost in the western Atlantic Ocean. Knowledge about migration, movements and identification of stocks of this important fishery resource is scarce. Thus, we aim to study movement patterns and to identify the presence of different fish stocks in the southwestern region of the Atlantic 2 Ocean, using cumulative otolith shape morphometric and microchemical analyses of sagittae otoliths. Specimens (n = 99) were obtained in four coastal areas: Paranaguá Bay in Brazil, Samborombón Bay, Mar Chiquita Coastal Lagoon, and San Blas Bay in Argentina. Otolith shape indices (Circularity, rectangularity, aspect ratio, percentage occupied by sulcus, ellipticity and form factor) were used for stock identification analysis; and otolith microchemistry using LA-ICP-MS (Sr/Ca and Ba/Ca ratios chronological variation) was used for both the analysis of movement behaviors and the identification of fish stocks (otolith edge ratios). Morphometrical indices did not revealed a clear separation among areas. San Blas bay individuals presented otoliths tending to be longer than wider, with a more elliptic shape than the otoliths from other studied areas; also, did not share individuals with the most northern one, Paranaguá Bay in Brazil. The analysis of microchemical lifetime profiles revealed three types of behavior pattern: Type I: most frequent use of estuarine environments; Type II: a fluctuating behavior between estuarine and sea/high salinity waters; Type III: most frequent use of sea/high salinity habitats. Otolith edge analysis did not reveal differences among Sr/Ca and Ba/Ca ratios for the different areas. Thus, it cannot be assured that there is more than one stock in the studied region. Mugil liza revealed different environmental migratory behaviors in the Southwestern Atlantic Ocean showing a facultative use of estuarine waters; hence, the species appears to be mostly coastal with the use of low estuaries, as seen also by the Sr/Ca otolith cores ratios; differing from the general mugilid behavior previoulsy described.

The aim of the present study was to evaluate the potential use of otolith microchemistry (Sr:Ca and Ba:Ca ratios) to identify silver mullet, Mugil curema, populations in Southeastern Caribbean Sea. Fish samples were collected in 7 areas of Nueva Esparta State (Venezuela). The otolith Sr:Ca and Ba:Ca ratios and water Sr:Ca were determined (by ICP-OES and EDTA volumetric method). Otoliths Sr:Ca and Ba:Ca ratios and Sr:Ca partition coefficient of mullets in Cubagua island (south of the State) were significantly different from ratios in La Guardia (north of the State). A discriminant analysis of otolith Sr:Ca and Ba:Ca ratios separated Cubagua Island from La Guardia values. These results suggest the existence of different mullet groups in the Southeastern Caribbean Sea. For this, the simultaneous use of Sr:Ca and Ba:Ca ratios could be a potential tool to identify populations in the study area.Keywords: Mugilidae, fish resource, otolith, microchemistry. A microquímica do otólito é um indicador do habitat de Mugil curema no sudeste do Mar Caribenho?Resumo O objetivo do presente estudo foi avaliar o potencial uso da microquímica do otólito (razões Sr:Ca e Ba:Ca) para identificar distintas populações de tainha, Mugil curema, no sudeste do mar caribenho. Os peixes foram coletados em 7 áreas do estado de Nueva Esparta (Venezuela). As razões Sr:Ca e Ba:Ca do otólito e a razão Sr:Ca da água foram determinadas (pelo ICP-OES e EDTA método volumétrico). As razões de Sr:Ca e Ba:Ca dos otólitos e o coeficiente de partição das tainhas da Ilha Cubagua (sul do estado) foram significativamente diferentes das razões de La Guardia (norte do estado). A análise discriminante das razões de Sr:Ca e Ba:Ca dos otólitos separa os valores da Ilha Cubagua e de La Guardia. Estes resultados sugerem a existência de diferentes grupos de Mugil curema no sudeste do mar Caribenho e que o uso simultâneo das razões Sr:Ca e Ba:Ca poderiam ser uma potencial ferramenta para identificar as populações da área de estudo.Palavras-chave: Mugilidae, recurso pesqueiro, otólito, microquímica.

The streaked prochilod Prochilodus lineatus (Valenciennes) is a commercially freshwater species from South America, distributed in the Plata basin. In the present work the morphometry (circularity, rectangularity, form factor, OL/OW and ellipticity indices) and chemistry (Sr:Ca, Ba:Ca, Zn:Ca) of lapilli otolith, and geometric morphometry of scales of streaked prochilod juveniles, in two sites in the Plata basin (Uruguay River and Estrella Wetland), were compared to determine if they are area-specific and to identify possible breeding areas. Otolith Ba:Ca ratios was 0.017±0.003 mmol/ mol for Uruguay River while for Estrella Wetland individuals was bellow the detection limits. Zn:Ca ratios tended to be higher for the latter (0.03±0.002 mmol/mol). Significantly high circularity and low rectangularity values were obtained for Estrella Wetland otoliths (p < 0.05), while no significant differences for form factor, OL/OW and ellipticity were observed between sampling sites. Considering all scale geometric morphometry variables, discriminant analysis showed a good percentage of classification of individuals (90.5% for Estrella Wetland and 85.7 % for Uruguay River). These results indicate that the otolith microchemisty and morphometry (circularity and rectangularity indices) and scale morphometry are good markers of habitat and represent a potential tool for identification of streaked prochilod nursery areas.El sábalo Prochilodus lineatus (Valenciennes) es una especie de importancia comercial de agua dulce de Sudamérica, distribuida en la cuenca del Plata. En este trabajo se comparó la morfometría (índices de circularidad, rectangularidad, factor de forma, OL/OW y elipticidad) y microquímica (Sr:Ca, Ba:Ca y Zn:Ca) del otolito lapilli, y la morfometría geométrica de las escamas de sábalos juveniles capturados en dos sitios de la cuenca del Plata (Río Uruguay y bañado la Estrella), para determinar si existen diferencias área-especificas e identificar posibles sitios de cría. La relación Ba:Ca del otolito fue 0.017±0.003 mmol/mol para el río Uruguay mientras que estuvo por debajo del límite de detección para los individuos del bañado la Estrella. La relación Zn:Ca tendió a ser más alta en el bañado la Estrella (0.03±0.002 mmol/mol). Se obtuvieron valores significativamente altos de circularidad y bajos de rectangularidad para el bañado la Estrella (p < 0.05), mientras que no se hallaron diferencias para el factor de forma, OL/OW y elipticidad. Considerando la morfometría geométrica de las escamas, el análisis discriminante mostró buenos porcentajes de clasificación (90.5% para el bañado la Estrella y 85.7 % para el Río Uruguay). Estos resultados indican que la microquímica y morfometría del otolito (índices de rectangularidad y circularidad) y la morfometría de las escamas son buenos marcadores de hábitat y representan una herramienta potencial para la identificación de sitios de cría del sábalo.

The Cattle Egret (Bubulcus ibis) is native to the old world. Before 1877 no Cattle Egrets had been sighted in the Americas. There are no written records of this species being transported to or escaping from captivity in South America and there is enough evidence to suggest that individuals are capable of making the crossing from Africa to the Americas unaided. Since long-distance movements of species are partly dependent on meteorological events we analyze the possibility of B. ibis crossing the Atlantic Ocean aided only by wind conditions evaluating existing theories and shedding light on their feasibility through the analysis of weather patterns and atmospheric circulation. Zonal and meridional wind components taken from the Twentieth Century Reanalysis Project were used to calculate trajectories between different points along the West African coast and South America between 1871 and 1920 in two seasons (March-April and September-October). From a total of 192,864 trajectories analyzed, 1,695 with origin in the west coast of Africa reached the NE coast of South America or the Caribbean islands in less than a week (successful trajectories). The probability of these successful trajectories originating in Central Africa was above 0.65 for the majority of the destinations analyzed. Particularly, in Guyana and Suriname where B. ibis was first sighted, the probability of the origin being Central Africa was 0.84, most of them occurring during March. Several weather events favored not only the colonization of the Cattle Egret but also its establishment and spread all throughout the Americas.

The study of otolith morphometry is a tool widely used in numerous studies of fish populations (fish stocks, taxonomic, ecological, ontogeny, among others). The aim of this study was to detect ontogenetic variations in the otolith of Odontesthes argentinensis through the application of traditional and geometric morphometry and the association of these variations with ecological and trophic habits of the species. Fish (52 to 360 mm TL) were collected seasonally between years 2013-2016 in the southwest coast of the Atlantic Ocean (36°39'30.96"S -56°40'40.09"W). Otolith shape indices (circularity, rectangularity, aspect ratio and surface occupied by sulcus) and Fourier descriptors were measured and compared through ontogenetic stages (I, II and III). The three stages analysed in the present study were differentiated by both traditional and geometric morphometry. The four analysed indices showed significant differences between stages (ANOVA Kruskal Wallis test, P < 0.001) and a simultaneous analysis of the morphometric variables also showed significant differences (Hotelling's T 2 < 0.001). The quadratic discriminant analysis performed on the Fourier descriptors showed a clear separation for each defined group. Therefore, the use of both methodologies simultaneously could be considered robust to evaluate the ontogenetic variations in this species. The observed changes could be associated to changes in the habitat throughout its development, to the sexual maturity of fish and to dietary shifting of these organisms.

Morphological and morphometric changes of sagittae otoliths related to fish 1 growth in three Mugilidae species. , 2007; Reichenbacher et al., 2007; Bustos et al., 2012 Bustos et al., , 2014 Veen et al., 2012; 53 Riet-Sapriza et al., 2013; Scartascini & Volpedo, 2013; Tuset et al., 2013 Tuset et al., , 2015 2009; González-Castro & Ghasemzadeh, 2015; González-Castro & Minos, 2015). where b represents the "constant of differential growth rate" (Corruccini, 1972). 116For the morphometrical analysis of identified groups, a shape indices analysis was used and sulcus perimeter (SP) and area (SA) were measured in millimeters (linear 120 measurements) or in square millimeters (areas) (Fig. 1) anterior margin, and a closed tubular cauda at least two times bigger than the ostium. 157Nevertheless, during their growth, the morphology of the sagitta of the studied mullets 158 presents differences. Each species has distinctive otolith morphology patterns as 159 described below. Size range > 370 mm SL (n = 65): sagitta with angled anterior region, and absence of 175 culminant point (Fig. 3). All Mugil liza specimens present a rectangular sagitta with a 176 tubular cauda slightly curved, and round to flattened posterior region (Fig. 3). (Table 2). 184Thus, smaller specimens show more rectangular otoliths, longer than wider, with a 185 greater surface of their medial face occupied by the sulcus. Dependence of SL on OL and OH is best described as power regressions presenting a Morphological descriptions 226Based on the observed morphological characters of the sagitta, the studied specimens

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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).