Mediterranean Marine Science

Published by Hellenic Centre for Marine Research
Online ISSN: 1791-6763
Print ISSN: 1108-393X
POSEIDON is a comprehensive marine monitoring, forecasting and information system in the field of operational oceanography, aiming to enhance environmental surveillance, protect the marine ecosystem and respond to environmental disasters, and to provide the decision makers and other users real-time data upon which to base their decisions. Furthermore, the POSEIDON system also fits the plans of the Global Ocean Observing System (GOOS) and particularly that of EuroGOOS (for Europe), having three principal objectives: (i) real time continuous meteorological and oceanographic observations, (ii) data management and evaluation, and (iii) data and information distribution and associated forecasting services. The environmental surveillance is primarily based upon oceanographic buoys. These buoys could be equipped with sensors to monitor air pressure, air temperature, wind speed, wind direction, radioactivity, light transmission (suspended particulate matter), wave height and period, surface currents, salinity, temperature, oxygen, chlorophyll, and nutrient salts. The transfer of data from the buoys to the master control station, based in NCMR (Athens), will be committed either by satellite and/or cellular communication systems. After data management and evaluation, the information and forecasts produced will be made available to the users
We present a study on four high sedimentation-rate marine cores with suppressed bioturbation effects, recovered along the northern margin of the eastern Mediterranean. We demonstrate that this region, central to the development of modern civilisation, was substantially affected throughout the Holocene by a distinct cycle of cooling events in the order of 2° C. In the best-preserved cases the onset of these events appears particularly abrupt, within less than a century. The cooling events typically lasted several centuries, and there are compelling indications that they were associated with increased aridity in the Levantine/NE African sector (ROSSIGNOL-STRICK, 1995; 1998; ALLEY et al., 1997; HASSAN, 1986; 1996; 1997a,b; MCKIM MALVILLE et al., 1998). Several of these episodes appear to have been coincident with cultural reorganisations, with indigenous developments (eg. cattle domestication, new technologies) and population migrations and fusion of peoples and ideas (HASSAN, 1986; 1996; 1997a,b; MCKIM MALVILLE, 1998). We infer that climatic events of a likely high-latitude origin (O'BRIEN et al., 1995; BOND et al., 1997; MAYEWSKI et al., 1997; ALLEY et al., 1997) caused cooling and aridity in and around the eastern Mediterranean via a direct atmospheric link, and therefore played an important role in the development of modern civilisation.
The state-of-art on alien species in the Mediterranean Sea is presented, making distinctions among the four subregions defined in the EU Marine Strategy Framework Directive: (i) the Western Mediterranean Sea (WMED); (ii) the Central Mediterranean Sea (CMED); (iii) the Adriatic Sea (ADRIA); and (iv) the Eastern Mediterranean Sea (EMED). The updated checklist (December 2010) of marine alien species within each subregion, along with their acclimatization status and origin, is provided. A total of 955 alien species is known in the Mediterranean, the vast majority of them having being introduced in the EMED (718), less in the WMED (328) and CMED (267) and least in the Adriatic (171). Of these, 535 species (56%) are established in at least one area. Despite the collective effort of experts who attempted in this work, the number of introduced species remains probably underestimated. Excluding microalgae, for which knowledge is still insufficient, aliens have increased the total species richness of the Mediterranean Sea by 5.9%. This figure should not be directly read as an indication of higher biodiversity, as spreading of so many aliens within the basin is possibly causing biotic homogenization. Thermophilic species, i.e. Indo-Pacific, Indian Ocean, Red Sea, Tropical Atlantic, Tropical Pacific, and circum(sub)tropical, account for 88.4% of the introduced species in the EMED, 72.8% in the CMED, 59.3% in the WMED and 56.1% in the Adriatic. Cold water species, i.e. circumboreal, N Atlantic, and N Pacific, make up a small percentage of the introduced species, ranging between 4.2% and 21.6% and being more numerous in the Adriatic and less so in the EMED. Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.
With this corrigendum, the authors of Zenetos et al. (2022) wish to notify readers of a small number of omissions and corrections in the updated inventory of Mediterranean non-indigenous species (NIS), recently undertaken by them, and amend the total number of NIS reported in the Mediterranean until December 2021.
Using a 2010 review of non-indigenous species (NIS) reported in the Mediterranean Sea as a baseline, this study undertakes a paramount revision of the non-indigenous species list in the region up to December 2021, re-evaluating the established, casual and failed introduction events of over 1366 taxa. In the light of new data and expert judgement, 14 species have been removed from the “established list” of the Mediterranean Sea inventory. The total number of validated NIS is close to 1000—751 established taxa and 242 casual taxa—while 23 species are considered as failed introduction. The rest are tagged as cryptogenic (58 taxa), questionable (70 taxa) or excluded (223 taxa). Mollusca have the highest diversity among established and casual NIS (230 taxa), followed by Pisces and Crustacea with 173 and 170 NIS respectively. The changes in establishment status reveal an accelerated rate of establishment (13%) between January 2020 and December 2021 (>6% yearly), compared to an establishment rate of 27% in the period 2011–2021 (<3% yearly). This increased establishment success is more pronounced in Crustacea (47%) and Pisces (43%) than in Polychaeta (27%) and phytobenthos (30%). In the period 2011–2021, 42% of the newly reported species were established (149 out of 352). On a shorter timescale, out of 79 new species reported in the period 2020–2021, 17 NIS (21.5%) have already established, a figure well above the 10% prediction of invasion theory on establishment success for Mediterranean marine NIS.
We studied Pycnogonida, sea spiders, collected from 54 samples of Corallina officinalis belts in the vicinity of Pula and the Brijuni National Park representing both exposed and sheltered localities as well as different levels of human impact. Seven species were identified, namely Achelia echinata, A. langi, Tanystylum conirostre, Anoplodactylus angulatus, A. pygmaeus, Trygaeus communis, and Callipallene tiberi. As we used a quantifiable standard sample size of 5 cm2, we could perform a statistical analysis of species richness and abundances. The exposed low human impact sites showed a significantly higher amount of both, specimens and species than the sheltered high impact sites. C. tiberi and A. echinata showed a significant preference for exposed low impact sites while T. conirostre was equally distributed among the habitat subtypes.
The smooth clam, Callista chione (Linnaeus, 1758), is a venerid bivalve widely appreciated in southern Spain where it represents the top commercial bivalve species in terms of landings and economic value. In this area, a total of 223 artisanal boats (68% of the artisanal fleet) are involved in shellfishing targeting bivalve molluscs, including the smooth clam. The artisanal mechanised dredging that targets C. chione in the northern Alboran Sea is described and the current exploitation status of its populations is analysed. A surplus-production model was run using ASPIC and used to assess the temporal variation in the levels of fishing for this bivalve throughout the study period (2002-2015), as well as to suggest conservation reference points that could guarantee the sustainable exploitation of this resource. During the study period, the maximum C. chione catch was registered in 2003 (306 t) and the minimum in 2006 (93 t). The ASPIC model for C. chione stock suggests that a Maximum Sustainable Yield (MSY) of 216 t could be produced from a total stock biomass of 983 t (Bmsy) at a fishing mortality rate of total biomass of 0.22 (Fmsy), with B/Bmsy and F/Fmsy values of 1.34 and 0.82, respectively, indicating that the stock is approaching good status.
Turbot, Scophthlalmus maximus, is a pleuronectiform fish that occurs in the northeast Atlantic along the European coast and in the Mediterranean Sea, and is produced in fish farms since the last quarter of the twentieth century. During a survey conducted in a turbot fish farm, nodular formations were occasionally observed in several organs, especially in the kidney and in the spleen. Microscopic observations showed that these nodules contained acid-fast bacilli. Molecular identification of the isolated bacteria revealed the Mycobacterium genus. Although no abnormal mortalities were evident morbidity was observed. The normal development and welfare of infected fish decrease and the condition factor, the haematocrit and haemoglobin concentration in blood decreases significantly with the increase of nodule abundance.
A direct consequence of sea warming is the shift in the distribution range of thermo-tolerant species that have the potential to determine novel inter-specific interactions, ultimately altering food web structures and ecosystem processes. In this study, we investigated the trophic position of the bluefish Pomatomus saltatrix (Linnaeus, 1766), a pelagic predator that has recently expanded its distribution in the Mediterranean basin and for which scant information is available on its functional role in recently-colonised areas. Nitrogen and carbon stable isotopes were determined in muscle tissues of bluefish specimens collected in south-east Italy in the Gulf of Taranto (NW Ionian Sea) and in the Strait of Otranto (SW Adriatic Sea) at two coastal sites showing contrasting oceanographic conditions. The bluefish trophic position (TP) was estimated using locally abundant forage fish species as isotopic baselines. The results indicated for bluefish from the Strait of Otranto a TP value of 5.1, significantly higher than that determined in the Gulf of Taranto (4.2), and exceeding stomach content-based estimations reported by the online database FishBase and by literature sources. A synthesis of 30 publications reporting isotopic data for the bluefish and its potential prey at a global scale indicated that the species’ trophic position varied considerably between 2.7 and 5.2. The observed variability depended on locationand on the baseline species used in the estimations. Yet, a significant difference in trophic position was observed for bluefish from transitional and inshore environments as compared with offshore areas, mirroring the results obtained from the Gulf of Taranto and the Strait of Otranto. The findings of the study highlight the high trophic plasticity characterizing the bluefish in recently colonized areas, suggesting that it may play a key role in facilitating the expansion of its distribution range. However, additional investigations are essential to provide an advanced resolution of the bluefish functional role in Mediterranean coastal food webs.
The Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) is a well-known habitat builder, and as such hosts a diversified faunal assemblage. Although polychaetes are one of the most abundant and diverse macrobenthic groups associated with C. caespitosa colonies, our knowledge of their ecological features in this association is still limited. The aim of this paper was to gather and compare the most comprehensive data available on polychaetes associated with C. caespitosa in the Adriatic and the Aegean Seas, and to test for differences between these geographic areas. To this end, differences were tested in terms of: (i) richness and structure of polychaete assemblages; (ii) feeding and functional traits of assemblages; (iii) the main factors influencing those aspects, (iv) the relationship between polychaete assemblages richness and Cladocora colony size, and estimate richness. Differences were observed between the Adriatic and the Aegean Seas, in terms of richness, species composition and relative proportion of the dominant feeding guild (filter feeders most abundant in the Aegean and carnivores in the Adriatic) and motility mode (sessile most abundant in the Aegean and motile in the Adriatic). Conversely, cosmopolitan and Atlanto-Mediterranean species dominated the assemblages in both geographic areas, and the same Species-Area Relation model proved to be effective for richness estimation in both geographic areas.
Blue swimming crab, Portunus segnis is a Lessepsian migrant into the Mediterranean and little is known about the biology of it in Iskenderun Bay, Northeastern Mediterranean, Turkey. In the present study the sex ratio, gonadal development stages, gonadosomatic index, size at first sexual maturity, and the fecundity of P. segnis were examined. The specimens of P. segnis were collected monthly from July 2014 to June 2015 (except February) with trawl net from the Yumurtalık Cove. The crabs were found throughout the year and were abundant between July to October (74%). Carapace width range of all samples was between 38.1-163.17 mm, and body weight ranged from 3.46-324.36 g. The population sex ratio was obtained Male:Female=0.7:1 which showed more abundant female population. Fifty percent of the female crabs attained sexual maturity when they reached the sized of 115-119.99 mm CW. The ovigerous female crabs ranging between 101.39- 154.03 mm CW can produced 139379 to 2745236 eggs. The mean fecundity of P. segnis was 1070425±580978 eggs with a mean carapace width of 130.04±12.77 mm. In Yumurtalık Cove, breeding season of P. segnis were observed throughout the year, except winter. Further studies are needed for assessing the reproductive biology of blue crabs in other locations of Turkey.
The mottled spinefoot Siganus fuscescens caught in the harbour of Gioia Tauro (Tyrrhenian Sea: 38.44428 N, 15.90459 E) on March 1 st 2020 at a depth of about 7 m. The fish is photographed alive measured 20 cm TL. The fish bait and hook are still in the mouth of the fish. A screenshot of the Facebook post is also shown (available at: 2397747120485890&set=gm.2573435486272639&type=3&theater&ifg=1).
The occurrence of Siganus fuscescens was recorded on March 1st 2020, within the harbour of Gioia Tauro, southern Tyrrhenian Sea (38.44428 N, 15.90459 E). The capture was realized by a recreational fisher and shared through a Facebook group. Here we illustrate this new record and discussed its relevance for Mediterranean bioinvasion research.
The age range of the 'Red Fish Project' members at the Facebook group, as provided by the social media platform.
The number and gender of Professional Fishers (PF), SCUBA divers (SD), and Amateur Fishers (AF) from all regions that provided the spiny lobster records of the study.
The study areas from Greek waters. Marked with red circles. Inlaid photos (top to bottom) by: Milorad Mikota Djuknic, Christos Efthymiou and Dimitris Ganigiannis.
The density of spiny lobster records from: (A) Chalkidiki Peninsula, (B) Sporades Islands, and (C) Psara-Antipsara Islands.
A: The number of spiny lobster individuals per habitat type and region. All records regard the Upper and Lower Infralittoral zones.
Research known as Citizen Science (CS) has been recognized as an important tool for both biodiversity restoration and fisheries management projects through active involvement of citizens and therefore for public environmental awareness too. CS projects should be well designed and state clear questions, that will benefit both the research goals and the citizen scientists themselves. In January 2019, the “Red Fish Project” group was created on Facebook consisting of SCUBA divers and fishers and offering the main data source and the relevant digital material. The project’s establishment was based on previous personal experience and following specific protocols. Further information was provided by personal communications. Till October 21st, 2020 the FB group consisted of 464 members who recorded 348 European spiny lobster individuals from all sub-regions of the Aegean Sea. Based on the findings of the present study it seems that most of the citizens were unaware that the species is listed as “Vulnerable” in the IUCN Red List. Lastly, we discuss the important role of the spiny lobster in the country’s culture and that it can be listed as a charismatic, flagship species for citizens to be ocean-literate since it has been shown, that it can raise the interest of recreational divers and increase their awareness.
The white gorgonian, Eunicella singularis, is thriving in Mediterranean hard-bottom communities; however, data regarding its distribution and ecology remain absent and insufficient, particularly in the southern Mediterranean Sea.In this study, the population structure and disturbance levels of the most common gorgonian in Tunisia were assessed for the first time. During two years (2015-2016), a total of 818 colonies of E. singularis was surveyed in five coastal sites, by scuba diving, between 7 to 40 m depth. Collected data included density, colony height, and extent of injury. Mean population density was 11.91 ± 7.42 colonies per m2 (mean ± SD). Mean and maximum colony heights were 16.49 ± 5.59 cm and 51 cm, respectively. Among populations, mean extent of tissue injury differed considerably, ranging from 12.47% to 58.88% and most affected colonies showed old necrosis. These data regarding the demographic structure and level of injuries are needed to provide insights into the conservation status of the Tunisian population of E. singularis. Indeed, data on the amount of necrosis could highlight the strength of the colonies’ exposure to mechanical impacts and are consequently crucial to study changes in their demographic structure over time. In fact, the size, structures, and the high level of tissue necrosis of the colonies suggest a low conservation status of the studied Tunisian populations.
Relationship between: A, size (shell maximum diameter, MD) and diameter of mature oocytes; B, size (MD) and density of oocytes (number of oocytes per gram of gonad); C, oocyte diameter and density of oocytes in the ovary; D, size (MD) and fecundity (number of oocytes in the gonad). The dotted lines in A and B indicate the mean of the values of the variable of the ordinate axis (where no correlation was detected between both variables). The dashed lines in C and D represent the fitted models obtained (see text).
Developmental stages and times post-fertilisation (min, minutes; h, hours; d, days) in Patella ferruginea, reared at 20 °C. A, irregular oocyte just extracted from ovary. B, round oocyte covered with chorion (not fully mature). C, Mature egg without chorion being fertilised by a spermatozoid (0 h). D, extrusion of polar body (20 min). E, two-cell stage showing rest of chorion (1 h, 22 min). F, 4-cell stage (2 h, 20 min). G, morula (4 h, 27 min). H, early swimming trochophore (13 h, 36 min). I, late swimming trochophore (15 h, 50 min). J, pre-torsional veliger (23 h, 15 min). K: late pre-torsional veliger (1 d, 3 h, 40 min). L, post-torsional
Summary of development in Patella ferruginea at 20 °C. Abbreviations: h, hours post-fertilisation; d, days hours post-fertilisa- tion.
Several reproductive issues and the larval development of the ferruginous limpet, Patella ferruginea Gmelin, 1791, an endangered species endemic from the western Mediterranean Sea, were studied to fill gaps in the knowledge of its life cycle.Average diameter of mature oocytes was 141.83 μm and mean oocyte density in the ovary was 283,800 oocytes/gram. No significant correlations were found between both oocyte diameter or density and female shell length. Female fecundity (number of oocytes per gonad) was significantly correlated with shell length and varied between 189,200 oocytes in a 40.0 mm female and 5,019,200 oocytes in an 86.4 mm female. However, there was considerable variability, in particular for largest females.Spawning induction was not achieved using usual molluscan aquaculture methods. Thus, oocytes obtained after dissection of females were used for fertilizations trials. Alkalinization treatments of seawater were used to test improvement in oocyte maturation and later fertilization rates. Treatment at pH 9 during 2 h produced the highest increase in the percentage of mature oocytes and in the fertilization rate; but these results showed high variability and were mainly significant when the initial degree of maturation was low. Sperm concentration experiments determined that best in vitro fertilization were performed at 105 and 5×105 spermatozoids/ml. The sequence and timing of the complete larval development of Patella ferruginea in laboratory conditions is described and illustrated here for the first time. At 20 °C, larvae became competent for metamorphosis 3 days after fertilization, but some crawling pediveliger larvae with a still well developed velum were found even 7 days after fertilization. Recruits 1-2 mm in length were achieved in low numbers from two of the last assays and were first detected between 131-141 days after fertilization. The resulting juveniles were monitored during two years and sex determination of five survivors at the end of this period showed that two were mature males, two mature females and one indeterminate.Our results show that the main reproductive traits or larval development of P. ferruginea hardly differ from those of other non-endangered Mediterranean or NE Atlantic limpet species. Therefore, its decline cannot be mainly attributed to some constraints of these traits as was previously suggested, but to human impact.On the other hand, it is feasible to complete the life cycle of this species in laboratory conditions, from fertilized eggs to mature individuals. However, an important part of the process like spawning induction was not achieved as gonads needed to be dissected fatally from females, although sperm could be obtained from males through non-lethal biopsies. At present, large-scale aquaculture production for reintroduction, restocking or stock enhancement purposes is neither possible nor an advisable conservation tool yet. Further study is required and meanwhile, an appropriate design of a network of effectively protected marine areas that ensures connectivity among extant populations is necessary.
Sardine is a fish species of great economic importance to Tunisia. Knowledge of genetic diversity and population distribution is essential for an efficient management and sustainability of any regional fishery. This study aimed to assessing the genetic structure and to specify the stocks of the European sardine (Sardina pilchardus). To this end, 83 specimens were collected from three localities along the Tunisian coast and analysed using mitochondrial DNA sequences. The results of sequence analysis determined the existence of variations in 40 single nucleotide sites within the 307 bp fragment of the cytb gene examined and defined twenty different haplotypes. Genetic diversity, estimated by haplotypic diversity, was high in all samples. Tunisian S.pilchardus samples show some level of genetic structuring. First, genetic differentiation between localities (ΦST estimates) was significant for all comparison. Second, the analysis of molecular variance AMOVA indicates a high level of genetic variation (ΦST = 0.093; P<0.001). The structural patterns identified can be explained largely in relation to the regional oceanographic features. In conclusion, this study provided initial genetic data in making inference of the genetic structure of S. pilchardus along the Tunisian coasts.
Correct species identification and description are fundamental to understand health status of marine ecosystems. The use of a single identification tool for species distinction can lead to species misidentifications, having major consequences on ecological studies. Here, we used an integrative taxonomic approach to identify benthic decapods belonging to the genera Galathea Fabricius, 1793 and Eualus Thallwitz, 1891, collected in the Mediterranean Sea. 23 Galathea and 22 Eualus individuals were morphologically analysed and sequenced at the mitochondrial COI gene to confirm their identity using BOLD Identification Engine. Morphological identification revealed the presence of two Galathea and three Eualus species, while species delimitation based on DNA barcoding of COI sequences strongly suggested the presence of three Galathea and four Eualus species. Molecular analyses suggested the potential presence of two still undescribed species: one cryptic to Galathea squamifera and one cryptic to Galathea intermedia. Contrasting results obtained by morphological identification and BOLD Identification Engine impeded the recognition of Eualus specimens and suggested misidentifications among BOLD reference records of Eualus cranchii, Eualus occultus and Eualus pusiolus. These results demonstrated that morphological identification overlooks cryptic species and that misidentifications may occur, highlighting the importance of using an integrative approach to increase the current taxonomic knowledge of benthic invertebrates.
Within the overwhelming increase of pollutants spilled into the sea, heavy metals are emerging contaminants due to their high toxicity, persistence, and accumulation in both the organisms and the environment. This study aims to assess the retention capability of lead and cadmium by the sponge Axinella damicornis under laboratory conditions. The sponges were exposed for 144 h to seawaters artificially polluted with Pb and Cd separately and with a mixture of the two metals. The retention efficiency of the sponge in removing the metals from seawater and the metal uptake in the sponge body at the end of the experiment were measured. The highest values were recorded for Pb: in the sponge, this metal resulted in 6 times and 9 times more concentrated than Cd, in the case of single and double contamination respectively. The metal concentrations, especially for Pb, were much higher in A. damicornis than in other organisms investigated in the sea. The synergistic effects of the mixture of Pb and Cd were also evaluated, and remarkable signs of stress and necrosis were recorded in the specimens exposed to the two metals combined. This study paves the way to the knowledge increasing on both the effective effects of heavy metal contamination on the organisms and on the possible use of A. damicornis as efficient tool for bioremediation of polluted seawaters.
Temperature serves a predominant motivator for movement and activity over a wide range of mobile marine ectotherms. Water temperature modulates the movements of many lobster species, which can vary widely over spatial and temporal scales. Providing insight into the thermal preferences (and refuges) that some lobsters seek remains a key tenet to our understanding of the behavioral ecology of these animals. The Mediterranean slipper lobster (Scyllarides latus) shows seasonal movements throughout most of its range and is subject to a changing thermal environment. We examined the seasonal movements of S. latus within a small marine reserve (Rosh Hanikra Marine Reserve, RHR) off the coast of Israel and tested the hypothesis that S. latus engage in increased movements when subjected to temperatures outside their range. We conducted a field survey in the RHR and tagged lobsters (n = 81, carapace length, CLavg= 88.7 ± 4.6) to investigate their activity during their putative summer movement. In the lab, we exposed a separate set of lobsters (n = 10, CLavg= 83.1 ± 6.1) to the same thermal profiles as in the field and assayed their locomotion using activity wheels. Field results revealed that lobsters tagged in shallow waters moved to deeper, cooler waters (~ 30 m) over the course of 2-2.5 months traveling an average distance of 3.4 km (range = 1-5 km). Our lab results showed that S. latus are more active at higher temperatures, but moreover, revealed that warming water temperatures elicited markedly longer movements over a similar timeframe. Combined, these findings suggest that increasing water temperatures in the eastern Mediterranean (Levant) may affect lobster movements and could alter seasonal patterns of distribution as well.
Retraction of: Mediterranean Marine Science, published online 13 July 2020Editor note: The authors are retracting this article.In the article, Potential effects of elevated temperature on seasonal movements in slipper lobsters, Scyllarides latus (Latreille, 1803), in the eastern Mediterranean (Vol. 21, 2020,, authors J. Goldstein and E. Spanier have made an honest error in the inaccurate interpretation of their special scientific permit that afforded them the opportunity to collect wild-caught animals in the field and release them in their study area, in the marine reserve where this work was conducted. More specifically, the study component that refers to the ‘field tagging study’, was carried out without the full scope of permitting guidance unbeknownst to the authors. Dr. R. Yahel and E. Miller, Marine Ecologists of the Israeli National Park Authority (INPA), have pointed this out and have since requested that the article be removed given that the application of the special use permit was misinterpreted and not exercised in an appropriate manner. The authors were also not able to forward the INPA with the field’s raw data that have been lost since this field study was carried out over eight years ago. The authors were not aware of this discrepancy at the time the field study was carried out, but they have agreed to remove the article out of respect and admiration of the INPA and the continued protection and conservation of the Mediterranean slipper lobster in coastal Israeli waters. However, this action of retraction does not change the overall outcome of the paper’s finding including the study design, analyses, scientific integrity, or overall conclusions. The authors will plan on publishing the laboratory-based portion of this study as a stand-alone manuscript at a future date.
Close-up view of the successive right pelvic fin steps of Raja radula from the Sea of Marmara. Each frame represents locomotion within 0.3 seconds of interval. (A: recovery phase; B – I: propulsion phase).  
A mature female rough ray (Raja radula Delaroche, 1809) individual was observed at Sea of Marmara during a scuba dive to perform pelvic fin walking and punting, which was a previously unrecorded rajid behaviour from the Mediterranean Sea. The underwater video footage were analyzed, in which the average distance travelled per punt was measured as 0.40 disc length (DL) at an average speed of 0.26DL per second.
In this study, some biological characteristics of the Golden grey mullet from the Gulf of Gabes (central Mediterranean, Tunisia) were examined; in particular, the gonado somatic index (GSI), hepato somatic index (HSI), condition factor (K), length at first sexual maturity (TL50) and fecundity (volumetric method) were calculated. The gonadosomatic index (GSI) indicated that the spawning season of the Golden grey mullet extends from October to December. The monthly variation of the hepato-somatic index (HSI) indicates that L. aurata saves lipid reserves in the liver. The length at first sexual maturity (TL50) was determined to be 23.73, 23.84 and 23.79 cm TL for female, male and combined sexes, respectively. In this study, the sex-ratio was unbalanced, with females dominating among large sized individuals (TL > 24.0 cm). Absolute fecundity, with a mean value of 286564, varied from a minimum of 210400 eggs for age 4+ to a maximum of 533600 for age 7+.
Saros Bay and sampling stations. 
Blind side (a) otolith; ocular side (b) otolith and nucleus (N). 
The length-frequency distribution for females and males of the four-spotted megrim ( Lepidorhombus boscii Risso, 1810) from Saros Bay. 
The length-weight relationships for females and males of the four-spotted megrim ( Lepidorhombus boscii Risso, 1810) from Saros Bay. 
In this study, the growth parameters of the four-spotted megrim, (Lepidorhombus boscii Risso, 1810), were studied in Saros Bay, which had been closed to bottom trawl fishing since 2000. The sex ratio of females to males was 1:0.42. Length-weight relationships were W=0.0032L3.31 and W=0.0069L3.04 for females and males, respectively. Growth parameters of the populations were L∞=49.8 cm, k=0.09 year-1, t0=-2.15 year for females; L∞=39.1 cm, k=0.11 year-1, t0=-2.59year for males. The growth performance index (φ') was found to be 2.35 and 2.23 for females and males, respectively.
Saros Bay and sampling stations. 
The length-weight relationships for females and males of the four-spotted megrim (Lepidorhombus boscii Risso, 1810) from Saros Bay. 
In this study, the growth parameters of the four-spotted megrim, (Lepidorhombus boscii Risso, 1810), were studied in Saros Bay, which had been closed to bottom trawl fishery since 2000. The sex ratio of females to males was 1:0.42. Length-weight relationships were W=0.0032L3.31 and W=0.0069L3.04 for females and males, respectively. Growth parameters of the populations were L∞=49.8 cm, k=0.09 year-1, t0=-2.15 year for females; L∞=39.1 cm, k=0.11 year-1, t0=-2.59 year for males. The growth performance index (Φ’) was found to be 2.35 and 2.23 for females and males, respectively.
Map showing records of Aristeus antennatus (Risso, 1816) in the eastern Mediterranean, including the latest report from the Turkish Aegean Sea coast.  
A female specimen of the deep-water red shrimp, Aristeus antennatus (Risso, 1816) was caught at depths of between 550 m and 670 m during 2005 by trawling off the Marmaris coast. A. antennatus is a species known to inhabit only the Levantine Sea coast of Turkey. This paper is on the first record of the species along the southern Aegean Sea coast of Turkey.
Colonies of Cladocora caespitosa (a) and Oculina patagonica (b) from the study area. Scale bars are approximately 2 and 0.5 cm, respectively.
Comparison of main morphological characters of Oulastrea crispata, Cladocora caespitosa and Oculina patagonica.
Map of the locations where Oulastrea crispata has been found to date in the Mediterranean Sea.
The zooxanthellate scleractinian coral Oulastrea crispata, a widely distributed species across central Indo-Pacific nearshore marine habitats, has been first reported from the Mediterranean Sea (Corsica) in 2014. Here we report on two new sites for this species in the NW Mediterranean Sea and provide a general description of external morphological characters of the colonies and a detailed account of the cnidom to help future identifications. Living specimens may appear virtually identical to small colonies (~5 cm) of the Mediterranean zooxanthellate scleractinian Cladocora caespitosa. While this species shows long, ramified, independent corallites, with cylindrical calices, O. crispata has enlarged, cup-like calices, which can be joined by the coenosteum. It also shows clear differences among several groups of nematocysts, principally the presence in the filaments of large penicilli (p-mastigophore) of one type, which are absent in C. caespitosa. Identifications based on underwater observations or even the analysis of photographs may easily lead to misleading identifications. We hypothesize that O. crispata may have gone unnoticed because of misidentifications as C. caespitosa. More detailed research is needed to get reliable maps of the actual distribution of this apparently non-indigenous species in the Mediterranean Sea.
One of the well- established alien species in the eastern Mediterranean basin is Bursatella leachii, also known as a lessepsian immigrant. The present paper provides a contribution to Bursatella leachii's distribution in the Bay of Izmir, Turkish Aegean Sea.
(A) Frame extracted from the video taken after the spawning event was observed; (B) Colour patterns displayed by the apparent female (top) and male (bottom). Grouper silhouette redrafted from Bruslé, 1985. Graphics edited by L. Drago.
This study describes the first ever reported direct observation of a pair spawning event and the reproductive liveries of the white grouper, Epinephelus aeneus. Spawning took place on a rocky bank located in the Marine Protected Area (MPA) of Tavolara-Punta Coda Cavallo (NE Sardinia, Italy), in the Western Mediterranean Sea. In the evening of August 4th, 2018, the spawning of two large-sized individuals (~90 cm total length), displaying distinct colour patterns, was observed using SCUBA diving. This direct observation is the first record of E. aeneus male reproductive livery, characterized by a darker coloration on the head, the dorsal part of the body and the caudal fin. In addition, information on the environmental conditions in which reproduction occurred was collected. At the study site, relatively high seawater temperatures were recorded at the time of the E. aeneus spawning (24 °C at 24.7 m), as well as over the 2018 summer months (July-September), even in deep waters (>35 m), compared to previous summers. The spawning event occurred in a coralligenous-dominated seascape where fishing is prohibited, while diving activities are allowed. The site hosts abundant populations of ecologically and commercially valuable fish species (e.g., groupers, sparid fishes), with significant proportions of large-sized individuals (i.e. reproducers). Further studies are needed to advance our knowledge of the white grouper, with a particular emphasis on reproduction and the importance of implementing effective protection measures. Prioritizing management actions at key reproductive sites, such as rocky banks, is essential for ensuring the protection and/or recovery of over-exploited species.
Satellite image showing sites where Iphione muricata specimens were collected along the Mediterranean coast of Israel. (1) Akhziv beach (2) Mikhmoret beach. Image by NASA. 
The Indo-Pacific scaleworm Iphione muricata was observed and caught in the Mediterranean Sea along the coast of Israel. Morphological and molecular diagnostic characters of the species are discussed. This is the first record of this alien species in the Mediterranean Sea, and its previous reports from the Suez Canal suggest its introduction via Lessepsian migration.
Elamena mathoei (Desmarest, 1823), males, Sidi Daoud, 37°02’40.61”N - 10°54’25.50”E. A-B, habitus; C, an- terior part of carapace in lateral view (largest specimen); D, right first gonopod. 
Mediterranean fauna is undergoing drastic modifications as a result of anthropogenic activities and global warming. The most important of these is the colonization of the Mediterranean Sea by alien species, many of them entering through the Suez Canal. While many of them are still confined to the Levant Basin, several have extended their distribution westwards to Tunisian waters. The presence of the Indo-west Pacific hymenosomatid crab Elamena mathoei on a rocky shore at Sidi Daoud, Cape Bon Peninsula, Tunisia, is the first Mediterranean record of this species. It is a testimony to the changes in the patterns of invasion in the Mediterranean Sea.
In January 2021 during a scientific survey to assess the economic impacts of a Mass Mortality Event, a single individual of the Gracile lizardfish Saurida gracilis (Quoy & Gaimard, 1824) was caught out of Korbous (Northern Tunisia). This observation, confirmed by genetic analysis, provides evidence on the occurrence of a new non-indigenous species in Mediterranean waters. The relevance of this finding for the current monitoring strategies implemented at the regional level are briefly raised and discussed.
Position of the urohyal bone in the oral cavity of an Aphanius. The photo is A. ginaonis from Wildekamp (1993).
Overview of the location of the studied Aphanius species in Persian Gulf region (below, the black symbols are from Hormuzgan basin, and the white triangular symbol is from Mond basin) and Southeastern Mediterranean Sea drainages (above). Map source: Wildekamp (1993).
Left side view of the urohyal bone of Aphanius species and its terminology. Ha, hypohyal attachment; Ba, basibranchial attachment; Ve ventral extension; De dorsal extension; Dp dorsal plate; Pde posterodorsal edge; Rb radial band; Lp lateral plate; Pe posterior edge; Ve ventral edge; Vp ventral plate; Co condyle (adapted from Kusaka, 1974).
Lateral view of the urohyal bone of the studied Aphanius species from the Persian Gulf region with their corresponding voucher numbers indicated below the urohyal bones. a-g Aphanius hormuzensis; h-I A. furcatus; j-k A. ginaonis; i-m A. stoliczkanus. Scale bar 0.5 mm.
Lateral view of the urohyal of the studied Aphanius species from Southeastern Mediterranean Sea basin with their corresponding voucher numbers indicated below the urohyal bones. a-b Aphanius mento; c-d A. sirhani. Scale bar 0.5 mm.
Among the skeletal elements in fishes, the urohyal bone which lies in the lower part of the head - the central part of the mandibular skeleton- has proved to be of special significance in fish systematics. The urohyal bone is considered to be a synapomorphic structure in teleostean fish. The urohyal bone of six brackish water Aphanius species (i.e., Aphanius hormuzensis, A. stoliczkanus, A. furcatus, A. ginaonis, A. mento, A. sirhani) was compared using morphological description and linear measurements to explore the effectiveness of urohyal bone morphology in the separation of the Aphanius species. Description of the urohyal bones and their morphological variation allowed identification of the A. furcatus, A. mento and A. sirhani from their relatives. Moreover, the UH.UL separates significantly A. dispar and A. ginaonis, and the MH.UL discriminates significantly A. mento from others studied relatives. Discriminant function analysis (DFA) separated the studied species with high classification success (overall mean 94.7%). These results suggest the power of urohyal bone morphology in separating of the Aphanius species analyzed, and highlighting the taxonomic value of the urohyal bone. By considering the phylogenetic relationships among the studied species, it can be concluded that the observed variation in their urohyal morphology is largely consistent with their phylogeny. This indicated that at least some morphological characters in the shape of urohyal bone in Aphanius are encoded probably by genetic factors, which can be used for species discrimination.
Feeding habits of the invasive spider crab Libinia dubia from the Mediterranean Sea were studied in the Gulf of Gabès (Tunisia) using the frequency of occurrence and points methods. The population was sampled at least monthly between November 2015 and October 2016. Stomach contents of 384 specimens were analysed. Results indicate that L. dubia is an herbivorous species exhibiting clear preferences for algae (ALG) and Magnoliophyta (MAG) (62.03%, 7.13 points and 59.36%, 5.3 points respectively) although Echinodermata (ECH), Porifera (POR), Cnidaria (CNI), Mollusca (MOL), Polychaeta (POL), Crustacea (CRU) and fish (FIS) were accidentally consumed along with Bryozoa (BRY), sediment (SED), and unidentifiable materials (UNM). The diversity of ALG ingested was studied in detail: Chlorophyceae were found in 87.93% of stomachs containing ALG and contributed most of points to the stomach contents (4.18 points) followed respectively by Phaeophyceae (81.03%, 2.27 points) and Rhodophyceae (40.95%, 0.68 points).Very low Vacuity Index was recorded (VI = 2.6%). Ingested items varied significantly with regard to the season (Chi-square test, χ2calculated = 87.86 > χ2theoretical = 7.81, df = 3, p < 0.05) and crab size (χ2calculated = 14.25 > χ2theoretical = 5.99, df = 2, p = 0.026). Insignificant differences were registered by studying Carapace Width-Stomach Weight (CW-SW) relationships (T-test, tcalculated < ttheoretical, p > 0.05). Kruskal-Wallis test was applied so that the composition of crab diet among groups could be compared (H = 1.1, df = 3, p = 0.77).
A single specimen of Xanthias lamarckii was collected on March 2013 from the shallow waters of Chtenia, a rocky islet near Rhodes Island, south-eastern Aegean Sea. The occurrence of this Indo-West Pacific species is reported for the first time in the Mediterranean waters and documents the ongoing process of biological invasion of the basin. The vector of introduction of X. lamarckii is unknown so far, waiting for future information on establishment and spread of the species in its new environment.
Location of the records of Actaeodes tomentosus in Rhodes Island (eastern Mediterranean).  
The male Actaeodes tomentosus (H. Milne Edwards, 1834) in life (specimen B in the text), carapace width 25.2 mm, carapace length 16.0 mm (A: frontal view, B: dorsal view, C: ventral view, D: detail, frontal view of the left chela).  
The presence of the crab Actaeodes tomentosus, native to the Indo-Pacific Ocean and the Red Sea, is documented for the first time in the Mediterranean Sea, on the basis of two specimens collected from Rhodes Island (Aegean Sea), a marine area particularly vulnerable to warm-water alien invasions. Along with the recent report of Xanthias lamarckii in similar conditions and region, the finding of another non-indigenous xanthid poses many questions regarding their occurrence in the area. Apart from Lessepsian migration, other possible vectors of introduction are therefore examined.
The specimen of Acanthurus xanthopterus collected off Alexandria, Egypt: A, after the second de-frozening, B: X-rays, C: mouth, white bar= 1 mm [lower jaw damaged]. (Photos A and C by O.M. Nour).
Acanthurus xanthopterus from off Alexandria, Egypt, freshly caught (A) (Photo by M. Adel), just de-frozen (B) and left pectoral fin (C, detail of B) (Photo credits: O.M. Nour).
An adult of Acanthurus xanthopterus Valenciennes, 1835 was caught in the waters off Alexandria, Egypt, in August 2021, through spearfishing. This finding documents the first occurrence of the species in the Mediterranean basin. Description of the specimen, morphometric measurements and meristic characters are given. The yellowfin surgeonfish is widely distributed in the Indo-Pacific region, absent in the Red Sea and it is a popular aquarium fish. Potential routes of introduction of the species into the Mediterranean are briefly discussed.
Life span, growth and cost of reproduction of Illex coindetii were examined for the first time in the southern Adriatic Sea, central Mediterranean Sea. Age and growth were investigated through statoliths reading. Cost of reproduction was explored by studying the relative investment between somatic and gonad growth. The life span of I. coindetii was less than nine months in both sexes. Females (128-234 days) showed longer life span than males (124-178 days). In both sexes the linear model best described the mantle length-at age data, while the exponential model provided the best fit to the total weight-at-age data. In terms of mantle length, females grew faster than males (average growth rate was 1.33 mm day- 1 in females and 1.00 mm day-1 in males). In terms of total weight, no significant differences were highlighted between growth curves of males and females. Mantle length, total weight, mantle weight and fin weight increased up to the latest maturity stage in both sexes. Immature and maturing individuals showed poorer body condition than mature counterparts in both sexes. Some evidences of a reproductive strategy more similar to a multiple-spawning than to a single-spawning species were found.
Living colonies of Aplidium proliferum from Ras Leona (Strait of Gibraltar, Morocco) at 22-25m depth: a) long colonies in the form of strings or ropes; b) small pioneer colonies attached to Paramuricea clavata; c) development of colonies on Paramuricea; d) detail of the colony. 
Zooids and larva of Aplidium proliferum: a) thorax and abdomen; b) postabdomen with ovary and testes; c) stomach with interrupted folds; d) transversal dissected stomach, showing the inner wall with folds; e) young larva. Bars: a, b = 500 µm; c,d,e = 250 µm. 
Distribution of Aplidium proliferum (from different authors). 
An unusual colonial ascidian with 1-2m in length, belonging to the genus Aplidium (Ascidiacea: Polyclinidae), has been sampled from the Strait of Gibraltar (Ras Leona, Morocco). The characteristics of the colony, zooids and larvae point us to A. proliferum. The species seems common in the NE Atlantic from the Shetland Islands to Mediterranean Sea, but it never has observed the size of colonies as found in this area, the Strait is the largest so far reported, which it is probably represents one of the longest ascidian worldwide.
Location of Tavolara Island (Sardinia, Italy; central Tyrrhenian Sea); the site where the specimen of Zebrasoma xanthurum was recorded.  
Photograph of the individual Zebrasoma xanthurum (~11- 12 cm total length) that was observed swimming on rocky reefs and Posidonia oceanica patches at Tavolara (photo: L. Magnani).  
The occurrence of a single individual of yellowtail tang Zebrasoma xanthurum (Acanthuridae) from Sardinia island (Italy), probably released from an aquarium, is reported. This observation represents the first record of this species in the Mediterranean Sea. General information on the Acanthurid fishes and other non-native species in the Mediterranean is discussed in the light of the ongoing ecological change taking place on rocky reef ecosystems with consideration of implications on the aquarium trade.
During a study aiming at the evaluation of the distribution of the soft-bottom community at different taxonomic scales, the family Syllidae was analysed to the species level. Among the identified material, one undescribed species belonging to the genus Sphaerosyllis Claparède, 1863 was found and two species constitute new reports for the Mediterranean Sea and for the Iberian Peninsula: Parapionosyllis cf. macaronesiensis Brito, Núñez and San Martín, 2000, and Syllis cf. mauretanica (Licher, 1999) n. comb., both only previously known from the subtropical Eastern Atlantic Ocean. The new species of Sphaerosyllis is mainly distinguished in having bulbous, small antennae, tentacular and dorsal cirri, small parapodial glands, with granular material, and compound chaetae with short blades. In this paper, we describe the new species and the specimens of the new reports.
An exuvia of an adult female spiny lobster was found off the coast of Haifa, Israel. The finding was identified as a moult of the Indo-pacific long-legged spiny lobster, Panulirus longipes longipes (A. Milne-Edwards, 1868) of the western spotted-legged form. The specimen is described and possible explanations associated with the finding of this tropical lobster from the Levant are discussed.
The reproductive behavior of the gastropod Charonia seguenzae (Aradas & Benoit, 1870) was studied through the description of 19 copulation and 21 egg laying events of 134 wild individuals. Findings in the present study regarding a part of the reproduction temperature range (20 to 23oC) and the demonstration of maternal care provided important information on their biology, behavior and ecology. Furthermore, observed polyandry by the females and collaborative care of embryonic sacks, were two aspects of the species reproductive biology that pose new questions both at ecological and evolutionary level.
Underwater pictures of Bathyphysa conifera observed on the 6th of May 2012 off Tarifa Island, Strait of Gibraltar, at the entrance of the Mediterranean Sea (35.9996° Ν, -5.6091° W). A: whole specimen; B: detail of posterior part of A. as -anterior siphosome; gz1 -young gastrozooid (no tentacle yet); gz2 mature gastrozooid (with tentacle); gzm -mouth of gastrozooid; gzp -pigmented mature gastrozooid; pn -pneumatophore; ps -posterior siphosome; t -tentacle (from mature gastrozooid). Scale Bar 10 cm.
The rarely observed cystonect siphonophore Bathyphysa conifera was recorded for the first time in shallow depth water (- 16 m) as a live specimen, at the entrance to the Mediterranean Sea by SCUBA divers. It is a delicate oceanic species, with earlier records coming mostly from deep water, where it readily adheres to deep sea fishing cables and nets, causing painful stings to fishermen. Deep water sightings from ROVs include in the North Atlantic, off Angola, the Gulf of Mexico and Monterey Canyon. The present specimen was swimming actively by contracting and expanding its stem, in a yo-yo movement. A review of all reliable records for this species worldwide has been carried out in order to gain a better knowledge of the present known distribution of this species, both geographical and bathymetric. Bathyphysa conifera may possibly represent an important component of the food web and be perhaps also a competitor to fish in the regions it inhabits.
Geographical location and sampling station (black bullet) of Erugosquilla massavensis.  
Erugosquilla massavensis ( , TL= 22.6 mm); dorsal view. (Photo: T.Ozcan).  
The indo-Pacific mantis shrimp, Erugosquilla massavensis was recently collected from Sigacik Bay, located on the Aegean coast of Turkey. It is the first record of the species along the Aegean coast of Turkey.
Benthic monitoring of the marine shallow bottoms off Menorca (Balearic Islands, western Mediterranean) has yielded several specimens of the leptostracan genus Paranebalia Claus, 1880. This finding constitutes the first report of the genus from European latitudes and the Mediterranean Sea and therefore the third leptostracan genus known from the Mediterranean. Specimens are described, illustrated, and compared to other known species; they might represent a new species but their state of maturity and the lack of appropriate diagnosis for the type species of the genus, Paranebalia longipes (Willemöes-Suhm, 1875), did not allow confirmation of its taxonomic status.
Coralligenous formations are biogenic structures typical of the underwater Mediterranean seascape. Their intricate, multi-layered species assemblages are composed of perennial, long-lived organisms, particularly vulnerable to natural or human-induced disturbances. Despite their high ecological role and conservation value, few studies have addressed the assemblages outside the NW Mediterranean. This is the first quantitative assessment of coralligenous in the N Aegean Sea (NE Mediterranean), specifically focusing at the upper bathymetric limit of assemblages that are dominated by the yellow gorgonian Eunicella cavolini. The number and percent cover of macrobenthic species were studied at depths of 18 to 35 m, using a photoquadrat method. A total of 99 benthic taxa were identified, out of which 89 perennial ones were used to investigate spatial patterns in assemblage structure, composition, and biodiversity. A mean number of 47 perennial taxa were recorded per site, with encrusting coralline algae and sponges being the dominant groups in percent cover and species number, respectively. Across the studied localities, structural complexity and community composition were overall similar, but assemblages presented distinctive differences at the level of sites highlighting the role of local abiotic and anthropogenic factors in the shaping of the coralligenous. Compared to the rest of the Mediterranean, assemblages hosted a similar number of taxa. However, the number and percent cover of erect bryozoans were generally low, while, apart from E. cavolini, other erect anthozoan species were absent. This work provides an important baseline for comparisons and monitoring at a local or Mediterranean scale level.
Current global distribution of P. pusilla. Black circles indicate the records where the species has been found (all references are shown in Table 1); the white circle indicates the type locality (Rio de Janeiro, Brazil); the star symbol indicates the locality that was recorded during the present study, and represents the first record made in European waters. Possible pathways of introduction are indicated with question marks.
Paracaprella pusilla Mayer, 1980 is a tropical caprellid amphipod species. It was first described from Brazil and is found to be very common along the Atlantic coast of Central America. Since its original description, P. pusilla has been found in prolific vol-umes at numerous widespread locations in tropical and subtropical seas around the world, and is primarily associated with fouling communities in harbors. A well established population of P. pusilla was recently found in Cádiz, southern Spain, which is both the northernmost collection and the first recorded finding of this species in European coastal waters. Ship fouling is the most probable vector for its introduction. The species was always found in association with the native hydroid Eudendrium racemosum (Cavolini, 1785) and appeared to display a mutualistic relationship with this host.
Location of the sampling area of Akyatan Lagoon and its drainage channel to Mediterranean (Google Earth Inc. 2017).
The aim of this study is to determine the levels of organochlorine-based pesticides and polychlorinated biphenyls in the edible muscle tissue of blue crabs Callinectes sapidus (Rathbun, 1896) that are harvested from Akyatan Lagoon in the Eastern Mediterranean Region of Turkey. The crabs were harvested in October 2010, January 2011 and March 2011. A total of fifty crabs were studied. A quantitative determination of residue levels was carried out through a Gas Chromatography-Electron Capture Detector (GC-ECD), and compared with acceptable contaminant levels. PCBs were the greatest source of contamination.. The predominant compounds were α-HCH, o,p’-DDE, PCB 28 (2,2',4,4'-PCB) and PCB 52 (2,2’,5,5’-PCB), with mean concentrations of 22.39, 59.45, 347.31 and 362.86 ng/gwet weights, respectively. The present work is highly significant and points out a chronic exposure to pollutants in Akyatan Lagoon. This ecosystem is protected under the Ramsar Convention (Convention on Wetlands of International Importance, especially as Waterfowl Habitat).
Sampling location (ñ) of Tylerius spinosissimus.  
Meristic and morphometric characters for the three specimens of Tylerius spinosissimus from the Mediterranean Sea.
Tylerius spinosissimus (Regan, 1908) from Iskenderun Bay, Turkey.  
The non-indigenous tetraodontid of Indo-Pacific origin Tylerius spinosissimus is recorded for the first time in Turkish waters and for the third time in the Mediterranean Sea. This record increases to 53 the number of Indo-Pacific alien fish species present along the coasts of Turkey.
Location of finding individuals of Beroe ovata in the Evvoikos Gulf of the Aegean Sea.
Length / width ratio (mm) of Beroe ovata from the Black Sea.
Ratio length and width (mm) of Beroe ovata from the Mediterranean.
Beroe ovata from the Black Sea (Photo: T.A. SHIGANOVA).
"Beroe ovata" from Mediterranean Sea (Photo: FABIEN NOMBA).
A new alien species Beroe ovata Mayer 1912 was recorded in the Aegean Sea. It is most likely that this species spread on the currents from the Black Sea. Beroe ovata is also alien to the Black Sea, where it was introduced in ballast waters from the Atlantic coastal area of the northern America. The species is established in the Black Sea and has decreased the population of another invader Mnemiopsis leidyi, which has favoured the recovery of the Black Sea ecosystem. We compare a new 1 species with the native species fam. Beroidae from the Mediterranean and predict its role in the ecosystem of the Aegean Sea using the Black Sea experience.
Top-cited authors
Argyro Zenetos
  • Hellenic Centre for Marine Research
N. Streftaris
  • Hellenic Centre for Marine Research
Nomiki Simboura
  • Hellenic Centre for Marine Research
Panayotis Panayotidis
  • Hellenic Centre for Marine Research
Sotiris Orfanidis