Niche differentiation within bacterial key-taxa in stratified surface waters of the Southern Pacific Gyre.

One of the most hostile marine habitats on Earth is the surface of the South Pacific Gyre (SPG), characterized by high solar radiation, extreme nutrient depletion, and low productivity. During the SO-245 "UltraPac" cruise through the center of the ultra-oligotrophic SPG, the marine alphaproteobacterial group AEGEAN169 was detected by fluorescence in situ hybridization at relative abundances up to 6% of the total microbial community in the uppermost water layer, with two distinct populations (Candidatus Nemonibacter and Ca. Indicimonas). The high frequency of dividing cells combined with high transcript levels suggests that both clades may be highly metabolically active. Comparative metagenomic and metatranscriptomic analyses of AEGEAN169 revealed that they encoded subtle but distinct metabolic adaptions to this extreme environment in comparison to their competitors SAR11, SAR86, SAR116, and Prochlorococcus. Both AEGEAN169 clades had the highest percentage of transporters per predicted proteins (9.5% and 10.6%, respectively). In particular, the high expression of ABC transporters in combination with proteorhodopsins and the catabolic pathways detected suggest a potential scavenging lifestyle for both AEGEAN169 clades. Although both AEGEAN169 clades may share the genomic potential to utilize phosphonates as a phosphorus source, they differ in their metabolic pathways for carbon and nitrogen. Ca. Nemonibacter potentially use glycine-betaine, whereas Ca. Indicimonas may catabolize urea, creatine, and fucose. In conclusion, the different potential metabolic strategies of both clades suggest that both are well adapted to thrive resource-limited conditions and compete well with other dominant microbial clades in the uppermost layers of SPG surface waters.

Assessing marine litter in a highly polluted area in the Mediterranean: A multi-perspective approach in the Saronikos Gulf, Greece.

Marine litter poses a significant environmental challenge in the Saronikos Gulf, Greece. Employing an integrated approach, data from both beach and underwater sites were analyzed. The average litter density on beaches was 2.61 items m-2, with plastic being the most common material, notably small polystyrene fragments and cigarette butts. The western part of the Gulf exhibited higher litter density, mainly due to surface circulation patterns. Most beaches fell short of meeting Good Environmental Status criteria for marine litter. Higher litter densities were observed in autumn. Benthic litter density decreased with depth, being 23 times higher in shallower waters, with plastic being the predominant type. This extensive study offers crucial insights into the pollution status and litter distribution in the Saronikos Gulf, contributing significantly to the global understanding of marine litter distribution on coastal ecosystems. Such information is crucial for raising awareness, informing policy decisions, and driving environmental actions.

A case study on blast fishing in illegal small scale fisheries in the Aegean Sea: Catch composition and observed external and internal abnormalities for 18 Osteichthyes fish species.

Blast fishing is an illegal, ecologically destructive fishing method, fatal for many fish species at large scales. Blast fishing using dynamite is preferred by the fishers, especially small scale fisheries in Turkey, as it requires minimal effort but still results in higher catches. In the current study, demonstration of 20 controlled real-time blasting results involves species composition, size of fish, catch rates, catch composition, commercial/discard ratios, CPUE estimates and clinical observations of external and internal abnormality symptoms of fish species. Blasting trials were carried out with special permission in limited numbers because of its harmful effect. The collected data was tested using PRIMER v6 and diversity indices were also analysed. For the similarity between collected species cluster analysis was used to examine the stability of the results. Multidimensional scaling (MDS) was also applied for the assessment of fish species in the catch. A total of 1014 individuals (63.8 kg) were collected and 18 fish species belonging to seven families were examined. According to laboratory examinations, it was found that blasting caused different external and internal abnormality symptoms in the sampled fish species during the study.

An expanded phylogeny of the genus Pseudamnicola (Gastropoda; Truncatelloidea; Hydrobiidae) across the Mediterranean Basin.

The genus Pseudamnicola Paulucci, 1878, is commonly found throughout the Mediterranean region. The genus displays considerable levels of endemism, accompanied by notable systematic and taxonomic ambiguity. However, the application of molecular data has proven highly effective in clarifying taxonomy and unveiling the diversity of cryptic species within the genus. Therefore, we employed all cytochrome c oxidase subunit I sequence data available and generated new ones from Greece to infer the phylogeny of the genus throughout its Mediterranean range and estimate the divergence times as well as the ancestral area of diversification. Our phylogenetic and time-estimate analyses demonstrate that with 36 to 38 extant Pseudamnicola species and genetic divergences across species ranging from 0.5% to 11.9% on average, the genus underwent relatively recent diversification during late Miocene (6.53 Ma), and the primary speciation events occurred during Plio-Pleistocene. The Italian Peninsula and Islands and the Ionian Drainages as defined by the Freshwater Ecoregions of the World are the ancestral regions of the genus following two different dispersal routes. Our study contributes to deepening our understanding of Pseudamnicola phylogeny by using data from throughout its range for the first time. This phylogeny provides evidence and confirms previous studies that relatively recent habitat isolation, followed by founder and dispersal events, has been one of the primary reasons for the evolution of the genus Pseudamnicola in the Mediterranean basin.

Occurrence, sources and water column distribution trends of suspended particle-associated aliphatic and polycyclic aromatic hydrocarbons in the open northeastern Mediterranean Sea.

Herein, we study the occurrence and water column distribution trends of suspended particle-associated aliphatic (AHCs) and polycyclic aromatic hydrocarbons (PAHs) collected from 36 offshore/deep sea locations across the open northeastern Mediterranean Sea. Total concentrations of the determined compounds fall within the range previously reported for non-polluted coastal and open sea locations worldwide. Mixed natural and anthropogenic sources were evident for the studied compounds, based on their molecular profile and several diagnostic indices. In all cases, an enhanced fossil signal typifying chronic oil pollution was evident along the water column. AHCs and PAHs mixtures characteristics varied significantly within the studied sub-regions, highlighting the importance of inputs from various point sources and dispersion pathways. The circulation characteristics of water masses along with biogeochemical features impact on the water column distribution trends and overall fate of the determined compounds in the study area.

Phosphate-related genomic islands as drivers of environmental adaptation in the streamlined marine alphaproteobacterial HIMB59.

IMPORTANCE: These results shed light on the evolutionary strategies of microbes with streamlined genomes to adapt and survive in the oligotrophic conditions that dominate the surface waters of the global ocean. At the individual level, these microbes have been subjected to evolutionary constraints that have led to a more efficient use of nutrients, removing non-essential genes named as "streamlining theory." However, at the population level, they conserve a highly diverse gene pool in flexible genomic islands resulting in polyclonal populations on the same genomic background as an evolutionary response to environmental pressures. Localization of these islands at equivalent positions in the genome facilitates horizontal transfer between clonal lineages. This high level of environmental genomic heterogeneity could explain their cosmopolitan distribution. In the case of the order HIMB59 within the class Alphaproteobacteria, two factors exert evolutionary pressure and determine this intraspecific diversity: phages and the concentration of P in the environment.

Variations in copepod composition and diversity in relation to eutrophication and hydrology in Izmir Bay, Aegean Sea.

Hyrographic and trophic gradient along Izmir Bay used to assess their effects on the copepod composition and diversity. Trophic state of the bay varied from oligotrophic in the outer region to hypertrophic condition in the inner region as stated by trophic index (TRIX). Aegean Sea water entrance and trophic conditions of the bay affected species assemblages. Oithona davisae, Oithona nana and Acartia clausi were associated with hyper-eutrophic conditions whereas the typical Aegean Sea species, such as Oncaea media group, Oithona similis, Paracalanus parvus, A. clausi, Farranula rostrata and Calocalanus styliremis were related to oligotrophic condition. Copepod diversity indices decreased linearly along the trophic gradient, from oligotrophic to hyper-eutrophic conditions, highlighting the substantial impact of eutrophication on the copepod community structure in the inner region. These findings emphasize TRIX's value in assessing eutrophication in anthropized systems, and immense potential for using copepod composition and diversity in monitoring programs for ecological assessments studies.

Metal levels in sediments and caged mussels in one of the industrial zones of the Eastern Aegean Sea.

Caged mussels make biomonitoring studies possible with their ability to take up pollutants in the industrial zones. The goal of this study was applied to assess metal levels in the biomonitoring organism Mytillus galloprovincialis Lamark, 1819 for transplantation from three locations for two periods (2016-2018) in the industrial zone of the Eastern Aegean Sea. Metals were also determined in sediments; high concentrations of Hg, As and Zn in surficial sediments of Nemrut Bay can cause hazardous impacts on the aquatic environment with respect to sediment quality guidelines. The highest contamination factor (Cf) was calculated for Hg (Cf = 10), suggesting serious anthropogenic pollution in the study area. According to Pearson product-moment correlation analysis, As is not correlated with other metals due to As mainly originating from natural sources. Hg, Cd, Pb and Cu concentrations increased in the transplanted mussels during a field transplant experiment because of chronic pollution from industrial activities. Cumulative effects of both the oil refinery and shipbreaking industry cause higher uptake of Hg, Cd, Pb and Cu in sampling station 3 as a result of higher exposure levels in transplanted mussels. Mussel consumption was compared with provisional maximum tolerable intake from literature; the estimated provisional intake (EDI) for Cd, Hg and Pb does not exceed maximum levels; however, Cu and Zn exceed reference EDI values. Since Nemrut Bay is heavily influenced by industrialisation, it is not a suitable region for seafood production.

Assessment of health risks due to toxic metals in demersal fish captured from Saros and Edremit Bays, Northern Aegean Sea.

Bays are vulnerable ecosystems generally located near densely populated areas where toxic metals tend to accumulate and stay longer, affecting marine life. This study aimed to investigate the age-based health risks arising from Hg, Cd, Pb, and As in demersal fish captured from two major bays in the Aegean Sea. For this purpose, red mullet, whiting, piper gurnard, and tub gurnard, frequently consumed species, were caught from Saros and Edremit Bays. Toxic metal concentrations were determined from the muscle tissue of fish. Health risk assessments were conducted by the estimation of weekly intake (EWI), provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), total THQ (TTHQ), and target carcinogenic risk (TR). Red mullet from Edremit Bay was the species with the highest toxic metal levels, which were 1.597 mg/kg, 0.041 mg/kg, 0.070 mg/kg, and 19.351 mg/kg for Hg, Cd, Pb, and As, respectively. Whiting from Edremit Bay had higher mean concentrations of Hg and As than those from Saros Bay. The levels of Hg, Pb, and As (0.328, 0.043, and 0.574 mg/kg) in the tub gurnard were higher in comparison with the piper gurnard (0.252, 0.020, and 0.382 mg/kg) caught in the same station in Saros. TTHQs of red mullet and whiting from the same bay were found to be > 1, indicating potential health risks for all nine age categories studied. On the other hand, TTHQs of all species from Saros Bay were determined to be > 1 for the first four age categories, which might trigger health risks for children and adolescents. According to the TR index for Pb, no risk was determined for the fish from both bays. However, TR calculations for inorganic As indicated high cancer risk in most of the age categories for red mullet and whiting from Edremit Bay. To sum up, the results revealed that the fish captured from Edremit Bay posed serious health risks in terms of Hg and As concentrations for all nine age categories. Surveillance and monitoring of toxic metal levels in demersal fish and population-based health risk evaluation are vital in heavily populated bays.

Spatio-temporal distribution of microplastic abundances in Izmir Bay (eastern Aegean Sea).

Microplastics (MPs) and their impacts have been extensively studied in the Mediterranean region. However, more research has yet to be conducted on assessing the extent of microplastic (MP) pollution in the eastern Aegean Sea, specifically in Izmir Bay. This study aims to evaluate the current state of MP pollution in surface water and sediment samples collected from Izmir Bay. Ten sampling stations were specifically selected, including locations near stream discharge points, maritime transportation piers, and port areas. Surface water samples were collected using a manta trawl net, while sediment samples were obtained using a Van Veen grab. The mean MP abundances in surface water ranged from 1,083,882 to 8,091,684 items/km2. Fragment type MPs were dominant. In terms of size category, it was found that MP s of 500µm size were dominant. The dominant color of MPs was white. ATR-FTIR analyses revealed that polyethylene and polypropylene were the dominant polymer types. MP concentrations in sediment ranged from 2,125 to 4,925 items/m2, with fiber-type MPs being the most abundant. Black-colored MPs were found to dominate in sediment samples. Overall, the MP levels in Izmir Bay were higher than previous studies findings. Therefore, it is crucial to conduct long-term monitoring studies to obtain more consistent and reliable data on MP pollution levels in Izmir Bay.

Phylogenomic and population genomic analyses reveal the spatial-temporal dynamics of diversification of the Nigella arvensis complex (Ranunculaceae) in the Aegean archipelago.

The continental-shelf islands of the Aegean Sea provide an ideal geographical setting for evolutionary-biogeographical studies but disentangling the relationships between palaeogeographical history and the times, orders of modes of taxon divergence is not straightforward. Here, we used phylogenomic and population genomic approaches, based on orthologous gene sequences and transcriptome-derived SNP data, to reconstruct the spatial-temporal evolution of the Aegean Nigella arvensis complex (Ranunculaceae; 11 out of 12 taxa). The group's early diversification in the Early/Mid-Pliocene (c. 3.77 Mya) resulted in three main lineages (Greek mainland vs. central Aegean + Turkish mainland/eastern Aegean islands), while all extant taxa are of Late Plio-/Early Pleistocene origin (c. 3.30-1.59 Mya). Demographic modelling of the outcrossing taxa uncovered disparate modes of (sub)speciation, including divergence with gene flow on the Greek mainland, para- or peripatric diversification across eastern Aegean islands, and a 'mixing-isolation-mixing (MIM)' mode of subspeciation in the Cyclades. The two selfing species (N. stricta, N. doerfleri) evolved independently from the outcrossers. Present-day island configurations are clearly insufficient to explain the spatial-temporal history of lineage diversification and modes of (sub)speciation in Aegean Nigella. Moreover, our identification of positively selected genes in almost all taxa calls into question that this plant group represents a case of 'non-adaptive' radiation. Our study revealed an episodic diversification history of the N. arvensis complex, giving new insight into the modes and drivers of island speciation and adaption across multiple spatiotemporal scales.

Multi-index assessment of sea bottom sediments of the Izmir Gulf, Aegean Sea: A study of interrelation between anthropogenic and hydrodynamic effects.

This study aimed to investigate the sediment transport pathways and geochemical parameters in the Izmir Gulf to determine the heavily impacted areas by natural and anthropogenic parameters. The grain size trend analysis was used to determine sediment transport patterns and, statistical methods were employed to identify the sources and distribution of chemical elements in sediments. The main factors that were affecting the area were identified as lithogenic, anthropogenic, maritime traffic, biogenic and shipyard activities. The tannery industry (Cr), maritime traffic and shipyard/dock activities (Cu and Zn), road traffic run-offs (Pb and Zn), and untreated domestic waste discharges (TOC and S) were identified as the sources of metals. Contamination rankings based on metal concentrations indicated higher pollution levels in the Inner Gulf compared to the Central Gulf. Zinc and chromium were found to pose significant risks to benthic organisms. The pollutants tended to accumulate in deposition zones, following sediment transport directions.

Neoadjuvant therapy in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) stages I-III were previously predominantly treated with surgery and chemotherapy. With the advent of Checkmate-816, neoadjuvant nivolumab and chemotherapy was FDA approved for the treatment of resectable NSCLC. There are several ongoing trials evaluating other neoadjuvant combinations of chemotherapy and immunotherapy as well as targeted therapies towards driver mutations. Here, we review previous clinical trials and discuss current ongoing trials' potential benefits and challenges.

Macro- and microplastic abundance from recreational beaches along the South Aegean Sea (Türkiye).

This study aimed to evaluate the abundance and diversity of macro- and microplastics in sand samples collected during summer and winter from eight different beaches used for recreational purposes located on the South Aegean coasts of Türkiye. According to the results, microplastic in fiber shape was dominant on all the beaches. The highest microplastic abundance was determined at Ölüdeniz Kumburnu Beach (360.00 ± 237.66 particles kg-1 dw) in summer and at Aktur Beach (358.33 ± 397.24 particles kg-1 dw) in winter. A significant positive correlation was found in the winter between microplastic amounts and wind speed. The study area is an important touristic center faraway from major cities and industrial areas. Thus, plastic pollution in this area may be the result of tourism activities in the summer, discharge waters from wastewater treatment plants or transportation by meteorological factors (like waves, wind or river flows).

Distribution of Aedes (Stegomyia) cretinus in Türkiye

OBJECTIVE: Aedes cretinus, a white and black stripped Aedes species, shares morphological similarities with Aedes albopictus and Aedes aegypti which are among the most important vectors and invasive species in the world. Due to its limited distribution and low population density, information on the biology and ecology of the species has been limited so far. This study aimed to determine distribution of Ae. cretinus in Türkiye. METHODS: Field works have been carried out in the Mediterranean, Aegean and Marmara Regions of Türkiye. Larval samples were collected by larval dippers while adult mosquito catches were performed using the human landing catch method and CDC-light traps. RESULTS: A total of 44 different Ae. cretinus populations were identified in the Mediterranean, Aegean and Marmara Regions of Türkiye. The larval specimen collected from small containers, tires, tree holes and natural small habitats. A plane (Platanus orientalis), walnut (Juglans regia), Türkiye oak (Quercus cerris), chestnut (Castenea sativa) and cedar (Cedrus libani) tree holes are the main larval habitats in which the specimen collected. In some localities, larvae were found together with Anopheles plumbeus, Anopheles claviger and Aedes geniculatus larvae in tree holes. Human landing catch method captured a greater number of females than CDC-light traps. CONCLUSION: This study determined the distribution of Ae. cretinus in Türkiye for the first time. Information on respective geographic distribution of Ae. cretinus is fundamental for effective control programmes. Further studies are needed to understand the biology and ecology of these species.

Prevalence of Transmitted Drug Resistance among HIV-1 Patients in the Aegean Region: Results from the Western Part of Turkey.

OBJECTIVES: This study aimed to analyze the antiretroviral drug resistance in antiretroviral treatment-naïve HIV-positive patients in the Aegean Region of Turkey from 2012 to 2019. METHODS: The study included 814 plasma samples from treatment-naïve HIV-positive patients. Drug resistance analysis was performed by Sanger sequencing (SS) between 2012-2017 and by next-generation sequencing sequencing (NGS) between 2018-2019. SS was used to analyze resistance mutations in the protease (PR) and reverse transcriptase (RT) gene regions using a ViroSeq HIV-1 Genotyping System. PCR products were analyzed with an ABI3500 GeneticAnalyzer (Applied Biosystems). The sequencing of the HIV genome in the PR, RT, and integrase gene regions was carried out using MiSeq NGS technology. Drug resistance mutations and subtypes were interpreted using the Stanford University HIV-1 drug resistance database. RESULTS: Transmitted drug resistance (TDR) mutation was detected in 34/814 (4.1 %) samples. Nonnucleoside reverse transcriptase inhibitor (NNRTI), nucleoside reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) mutations were identified in 1.4 % (n =12), 2.4 % (n =20), and 0.3 % (n = 3) of samples, respectively. The most common subtypes were B (53.1 %), A (10.9%), CRF29_BF (10.6%), and B + CRF02_AG (8,2%). The most common TDR mutations were E138A (3.4%), T215 revertants (1.7%), M41L (1.5%), and K103N (1.1%). CONCLUSION: Transmitted drug resistance rate in the Aegean Region is compatible with national and regional data. Routine surveillance of resistance mutations may guide the safe and correct selection of initial drug combinations for antiretroviral therapy. The identification of HIV-1 subtypes and recombinant forms in Turkey may contribute to international molecular epidemiological data.

The AEGEAN-169 clade of bacterioplankton is synonymous with SAR11 subclade V (HIMB59) and metabolically distinct.

Bacterioplankton of the SAR11 clade are the most abundant marine microorganisms and consist of numerous subclades spanning order-level divergence (Pelagibacterales). The assignment of the earliest diverging subclade V (a.k.a. HIMB59) to the Pelagibacterales is highly controversial, with multiple recent phylogenetic studies placing them completely separate from SAR11. Other than through phylogenomics, subclade V has not received detailed examination due to limited genomes from this group. Here, we assessed the ecogenomic characteristics of subclade V to better understand the role of this group in comparison to the Pelagibacterales. We used a new isolate genome, recently released single-amplified genomes and metagenome-assembled genomes, and previously established SAR11 genomes to perform a comprehensive comparative genomics analysis. We paired this analysis with the recruitment of metagenomes spanning the open ocean, coastal, and brackish systems. Phylogenomics, average amino acid identity, and 16S rRNA gene phylogeny indicate that SAR11 subclade V is synonymous with the ubiquitous AEGEAN-169 clade and support the contention that this group represents a taxonomic family. AEGEAN-169 shared many bulk genome qualities with SAR11, such as streamlining and low GC content, but genomes were generally larger. AEGEAN-169 had overlapping distributions with SAR11 but was metabolically distinct from SAR11 in its potential to transport and utilize a broader range of sugars as well as in the transport of trace metals and thiamin. Thus, regardless of the ultimate phylogenetic placement of AEGEAN-169, these organisms have distinct metabolic capacities that likely allow them to differentiate their niche from canonical SAR11 taxa. IMPORTANCE One goal of marine microbiologists is to uncover the roles various microorganisms are playing in biogeochemical cycles. Success in this endeavor relies on differentiating groups of microbes and circumscribing their relationships. An early-diverging group (subclade V) of the most abundant bacterioplankton, SAR11, has recently been proposed as a separate lineage that does not share a most recent common ancestor. But beyond phylogenetics, little has been done to evaluate how these organisms compare with SAR11. Our work leverages dozens of new genomes to demonstrate the similarities and differences between subclade V and SAR11. In our analysis, we also establish that subclade V is synonymous with a group of bacteria established from 16S rRNA gene sequences, AEGEAN-169. Subclade V/AEGEAN-169 has clear metabolic distinctions from SAR11 and their shared traits point to remarkable convergent evolution if they do not share a most recent common ancestor.

Red porgy's (Pagrus pagrus) cellular physiology and antioxidant defense in response to seasonality.

Physiological stress patterns of marine organisms in their natural habitats are considerably complex in space and time. These patterns can eventually contribute in the shaping of fish' thermal limits under natural conditions. In the view of the knowledge gap regarding red porgy's thermal physiology, in combination with the characterization of the Mediterranean Sea as a climate change ''hotspot'', the aim of the present study was to investigate this species biochemical responses to constantly changing field conditions. To achieve this goal, Heat Shock Response (HSR), MAPKs pathway, autophagy, apoptosis, lipid peroxidation and antioxidant defense were estimated and exhibited a seasonal pattern. In general, all the examined biochemical indicators expressed high levels parallel to the increasing seawater temperature in spring, although several bio-indicators have shown increased levels when fish were cold-acclimatized. Similar to other sparids, the observed patterns of physiological responses in red porgy may support the concept of eurythermy.

Some like it hotter: Differential thermal preferences among lizard color morphs.

Temperature rules the lives of ectotherms. To perform basic biological functions, ectotherms must make behavioral adjustments to keep their body temperatures near a preferred temperature (Tpref). Many color polymorphic lizards are active thermoregulators and exhibit morph differences in traits related to thermoregulation, such as color, body size, and microhabitat use. The Aegean wall lizard, Podarcis erhardii, is a heliothermic lizard with orange, white, and yellow color morphs that differ in size, behavior, and microhabitat use. Here, we tested whether P. erhardii color morphs from the same population from Naxos island, Greece, differ in Tpref. We hypothesized that orange morphs would prefer lower temperatures than white and yellow morphs because orange morphs are often found on cooler substrates and in microhabitats with more vegetation cover. We obtained Tpref for 95 individuals using laboratory thermal gradient experiments of wild-caught lizards and found that orange morphs do, indeed, prefer cooler temperatures. Average orange morph Tpref was 2.85 °C lower than average white and yellow morph Tpref. Our results add support to the idea that P. erhardii color morphs have multivariate alternative phenotypes and present the possibility that thermally heterogeneous environments play a role in the maintenance of color polymorphism in this species.

Feeding Habits of Dentex maroccanus and the Effect of Body Size.

The feeding habits of organisms are important elements in their ecological role and are affected by several factors. The present study provides for the first time information on the diet and feeding strategy of Dentex maroccanus (Valenciennes, 1830) and examines the effects of various factors on the species' feeding activity. Various indices (vacuity index, numerical and weight proportion, frequency of occurrence, alimentary coefficient, index of relative importance, diet breadth and overlap, Shannon-Wiener index, and trophic level) were estimated. The diet of the species consisted of 18 different prey taxa. The most important prey taxon was Decapoda. The study of the feeding strategy showed the narrow width of the species. Body size was found to significantly affect the species' feeding habits. Polychaeta and Stomatopoda were found only in individuals with size ≥165 mm, Bivalvia mainly in sizes ≤120 mm, and Decapoda in the intermediate sizes. The largest individuals showed the lowest overlap with all other size groups. The trophic level increased from 3.7 in young individuals to 4.0 in larger sizes, indicating the carnivorous character of the species. The results of the present work contribute to a better knowledge of the species' feeding ecology.