Novi podaci o maču srebrnjaku Trachipterus trachypterus Gmelin, 1789. i srporibi srebrnici Zu cristatus (Bonelli, 1820) (Pisces: Trachipteridae) iz Sredozemnog mora

In this paper we report data on four juvenile individuals of T. trachypterus and one adult of Z. cristatus, from the Strait of Messina and southern Tyrrhenian Sea, respectively (Mediterranean Sea). Information on morphometric and meristic characters are provided together with some biological data such as prey and age estimation. Only stomachs of T. trachypterus contained prey: copepods, amphypods and pelagic snails. The analysis of growth patterns in vertebrae of Z. cristatus allowed to estimate an age of 4 years for this individual. We also combined our data together with information from bibliographic sources and estimated the relationships between total length and standard length, as well as total length and body mass, for these two species.U ovom radu objavljujemo podatke o četiri juvenilne jedinke T. trachypterus i jednoj zreloj jedin- ki. Z. cristatus, iz Mesinskog tjesnaca, odnosno južnog Tirenskog mora (Sredozemno more). Podaci o morfometrijskim i merističkim značajkama daju se zajedno s nekim biološkim podacima kao što su plijen i procjena starosti. Samo želuci T. trachypterus sadržavali su plijen: kopepode, amfipode i pelagične puževe. Samo želuci T. trachypterus sadržavali su plijen: kopepode, amfipode i pelagične puževe. Anali- za obrazaca rasta u kralješcima Z. cristatus omogućila je procjenu starosti ove jedinke od 4 godine. Također smo spojili naše podatke zajedno s informacijama iz bibliografskih izvora i procijenili odnose između ukupne duljine i standardne duljine, kao i ukupne duljine i tjelesne mase za ove dvije vrste

Edad y crecimiento del pámpano, Trachinotus ovatus, del Estrecho de Messina (Mediterráneo central)

This is the first paper to provide detailed information on the age and growth of Trachinotus ovatus. The size of the 244 individuals collected in the Strait of Messina ranged from 2.7 to 30.4 cm in fork length (LF) and 0.31 to 508.6 g in body mass (M). The relationship between these parameters (M - LF) was investigated and showed a good fit. Age estimation based on vertebrae and otoliths yielded similar results, suggesting a maximum age of five years. However, the precision and accuracy tests, such as percentage of agreement (PA), mean coefficient of variation (ACV) and average percent error (APE) indicated that the otolith readings (97.83% PA, 0.54% ACV and 0.38% APE) were more reliable for age estimation than vertebrae readings (82.17% PA, 5.33% ACV and 3.77% APE). The multi-model inference approach allowed us to compare different non-linear growth models. The von Bertalanffy model (L∞=29.139, k=0.496 and t0=−0.347) fitted the length-at-age data best. This species has a relatively rapid growth and an estimated longevity of five to seven years. This information could be used for management and first stock assessment studies on T. ovatus in the Mediterranean Sea.Este es el primer artículo que proporciona información detallada sobre la edad y el crecimiento de Trachinotus ovatus. El tamaño de los 244 individuos recolectados en el Estrecho de Messina osciló entre 2.7 y 30.4 cm de longitud a la horquilla (LF) y 0.31 a 508.6 g de masa corporal (M). Se investigó la relación entre estos parámetros (M - LF) y mostró un buen ajuste. La estimación de la edad basada en vértebras y otolitos arrojó resultados similares, lo que sugiere una edad máxima de cinco años. Sin embargo, las pruebas de precisión y exactitud, como el porcentaje de concordancia (PA), el coeficiente medio de variación (ACV) y el porcentaje de error medio (APE), indicaron que las lecturas del otolito (97.83% PA, 0.54% ACV y 0.38 % APE) fueron más confiables para la estimación de la edad que las lecturas de vértebras (82.17% PA, 5.33% ACV y 3.77% APE). El enfoque de inferencia de modelos múltiples nos permitió comparar diferentes modelos de crecimiento no lineal. El modelo de von Bertalanffy (L∞=29.139, k=0.496 and t0=−0.347) se ajusta mejor a los datos de talla por edad. Esta especie tiene un crecimiento relativamente rápido y una longevidad estimada de cinco a siete años. Esta información podría utilizarse para la ordenación y los primeros estudios de evaluación de poblaciones de T. ovatus en el mar Mediterráneo

When opportunistic predators interact with swordfish harpoon fishing activities: shark depredation over catches in the Strait of Messina (central Mediterranean Sea)

We describe the interaction between harpoon fishing activity and sharks, which opportunistically depredated harpoon catches in the Strait of Messina. Shark bite marks were observed on harpooned swordfish during the period 2014–2020, with different damages to the catches. Most of the depredation events have focused on large swordfish, generally weighing more than 60 kg. Data on direct observations were implemented by interviews and questionnaires to fishermen aimed to recover the information on their local fishing and ecological knowledge. Fishermen provided additional data on shark-harpoon fishing interactions also supplying information on by-catch species (i.e., bluefin tuna). Therefore, these results suggest that sharks migrating through the Strait of Messina are occasionally attracted by injured prey, due to their ability to detect chemical cues, fish distress stimuli and body fluids (i.e. blood) in the water. In addition, our investigations showed an increase in shark attacks on harpooned fish over time, likely due to an increase in harpoon swordfish catches. This may be related to the effects of the driftnets' ban enforced by European Regulations in the last decades

“New records of rare species in the Mediterranean Sea” (October 2021)

“New records of rare species in the Mediterranean Sea” (October 2021

Isolation and Identification of Luminescent Bacteria in Deep Sea Marine Organisms from Sicilian Waters (Mediterranean Sea)

Luminescent bacteria are a fascinating component of marine microbial communities, often related to the light emissions in deep sea marine organisms. They are mainly affiliated with specific phylogenetic groups, such as Photobacterium, Vibrio, and Photorhabdus, and are sometimes involved in symbiotic relationships. However, the luminescence of some marine organisms remains a poorly understood process, and it is not always certain whether their luminescence is attributable to associated luminescent bacteria. In this study, for the first time, luminescent bacteria were isolated from two deep sea organisms, namely, the cephalopod Neorossia caroli and the teleost Chlorophthalmus agassizi. The isolation was carried out on glycerol-supplemented medium, and the search for the luxAB gene was performed on all isolates as a complementary tool to the culture-dependent techniques to detect bioluminescence by molecular approach. The optimum of salinity, temperature, and pH was evaluated by physiological tests for all isolates. The production of extracellular polymeric substances was also preliminarily screened. A total of 24 luminescent isolates were obtained, with an abundance from C. agassizi specimens. All the isolates were taxonomically characterized and were related to different species of Photobacterium, with the exception of Vibrio sp. CLD11 that was from C. agassizi. The luxAB gene was detected in about the 90% of the analysed strains

Importance of the Lunar Cycle on Mesopelagic Foraging by Atlantic Bluefin Tuna in the Upwelling Area of the Strait of Messina (Central Mediterranean Sea)

The influence of the lunar cycle on bluefin tuna foraging in the upwelling area of the Strait of Messina was investigated by exploring trophic interaction with mesopelagic fish and cephalopod prey. To focus on how the lunar cycle could affect availability of mesopelagic prey for this predator, we tested potential differences in the diet related to each lunar phase. Moreover, we considered two potential impacts of the lunar cycle: the lunar irradiance and the strength of currents. Overall, 2672 prey items were mesopelagic fish and cephalopods, representing 60.7% of overall diet by number. The main mesopelagic fish prey items were lanternfishes and dragonfishes, while Onychoteuthis banksii was the most important cephalopod prey. In summary, the Strait of Messina has highly specific hydrodynamic and biological features which strongly depend on upwelling currents, which in turn are influenced by the lunar cycle (new and full moon with strong currents, quarters with fewer currents). Upwelling causes water mixing, bringing to the surface a large amount of mesopelagic fauna which become more readily available to tuna. Lunar irradiance contributes to the variation of prey composition, increasing the success of visual predation on mesopelagic resources at high light in the water column

New records of rare species in the Mediterranean Sea (October 2021)

This Collective Article presents information about 27 taxa belonging to five Phyla (one Ochrophyta, one Cnidaria, three Arthropoda, two Mollusca and twenty Chordata) and extending from the Western Mediterranean Sea to the Levantine Sea and the Black Sea (Sea of Marmara). The new records were reported from 11 countries as follows: Algeria: occurrence of the African striped grunt Parapristipoma octolineatum; Spain: new records of eight uncommon fish species (Gadella maraldi, Hypleurochilus bananensis, Lobotes surinamensis, Parapristipoma octolineatum, Selene dorsalis, Sphoeroides marmoratus, Tetragonurus cuvieri, and Trachyrincus scabrus) from the Spanish Mediterranean; Italy: new record of the football octopus Ocythoe tuberculata from the Southern Tyrrhenian Sea; a rare sighting of a juvenile phase of a moray eel of the genus Gymnothorax, tentatively identified as Gymnothorax cf. unicolor in the Ligurian Sea; first record of adult Facciola's sorcerer Facciolella oxyrhynchus in the Adriatic Sea; occurrence of the tope shark Galeorhinus galeus in the Northern Adriatic Sea; Libya: first confirmed record of the pen shell Pinna rudis; first documented record of the palaemonid shrimp Brachycarpus biunguiculatus; first record of the fish Sudis hyalina; Malta: new records of Grant's rockling, Gaidropsarus granti; multiple concomitant reports of the rare hydromedusan species Aequorea forskalea; Croatia: a record of the skipjack tuna Katsuwonus pelamis in the Southern Adriatic Sea; Albania: new record of the bigeye thresher shark Alopias superciliosus; Greece: confirmation of the rare brown alga Sargassum flavifolium occurrence in the Eastern Mediterranean Sea; first record of the scaleless dragonfish Bathophilus nigerrimus; Turkey: first occurrence of the calanoid copepod Pteriacartia josephinae in the Aegean Sea; first documented record of the Cremona's sea slug Placida cremoniana for the easternmost Mediterranean Sea; new record of the yellow-headed goby Gobius xanthocephalus in the Sea of Marmara; Cyprus: first record of the Liechtenstein's goby Corcyrogobius liechtensteini; an individual of the Yellow fin tuna Thunnus albacares captured with handline by an artisanal fisher; Lebanon: an individual of the Black marlin Istiompax indica captured in a gill net

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)