The biology and ecology of juvenile pilotfish (Naucrates ductor) associated with Fish Aggregating Devices (FADs) in eastern Mediterranean waters

The pilotfish (Naucrates ductor) is an epipelagic oceanic species, whose 0-group specimens tend to aggregate below flotsam, constituting a principal by-catch of the western Mediterranean FAD fishery. During a one-year survey sampling, monthly experimental hauls using surrounding nets were conducted at sites in south Peloponnesian waters, where FADs were moored; during the summer-early autumn months bongo tows were also carried out. 0-group pilotfish appeared beneath FADs from mid-summer till early winter and the total length of the collected specimens ranged between 120 and 330 mm. Pilotfish larvae, measuring 2.0- 3.9 mm, were found at FAD sites in mid-summer and in early autumn. The age of juvenile specimens, determined by counting daily increments on their sagittae, ranged between 50-141 increments (days) for males, and 51-131 increments (days) for females. The predicted asymptotic length was found to be 412.3mm TL for males and 435.2 mm TL for females. The onset of sexual maturity appeared to occur when specimens were a few months old. Stomach content analysis suggested that the diet of 0-group pilotfish associated to FADs in Greek waters depended mainly on decapod larvae, hyperiid amphipods, and alciopid polychaetes

Annotated records of scombroid eggs and larvae distribution in northeastern Mediterranean waters

The distribution of eggs and larvae of scombroid fish in northeastern Greek waters were studied during the summer of three consecutive years(1992-1994) to determine spawning, time of spawning peaks, and the possible preferred spawning grounds. Among eggs only those of Xiphias gladius were successfully identified. Larvae of Thunnus alalunga, Euthynnus alleteratus, X. gladius and Auxis rochei were recorded, the latter species being encountered more frequently than the rest. Most scombroid larvae were collected in the Sporades Islands’ basin and their abundance, particularly that of A. rochei, was relatively increased at the end of the summer, possibly suggesting increased spawning activities during that period

New Mediterranean Biodiversity Records (April 2015)

The Collective Article ‘New Mediterranean Biodiversity Records’ of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided in two parts, for records of native and alien species respectively. The new records of native fish species include: the slender sunfish Ranzania laevis and the scalloped ribbonfish Zu cristatus in Calabria; the Azores rockling Gaidropsarus granti in Calabria and Sicily; the agujon needlefish Tylosu¬rus acus imperialis in the Northern Aegean; and the amphibious behaviour of Gouania willdenowi in Southern Turkey. As regards molluscs, the interesting findings include Ischnochiton usticensis in Calabria and Thordisa filix in the bay of Piran (Slovenia). The stomatopod Parasquilla ferussaci was collected from Lesvos island (Greece); the isopod Anilocra frontalis was observed parasit¬izing the alien Pteragogus trispilus in the Rhodes area. The asteroid Tethyaster subinermis and the butterfly ray Gymnura altavela were reported from several localities in the Greek Ionian and Aegean Seas.The new records of alien species include: the antenna codlet Bregmaceros atlanticus in Saronikos Gulf; three new fish records and two decapods from Egypt; the establishment of the two spot cardinal fish Cheilodipterus novemstriatus and the first record of the marble shrimp Saron marmoratus in semi-dark caves along the Lebanese coastline; the finding of Lagocephalus sceleratus, Sargocentron rubrum, Fistularia commersonii and Stephanolepis diaspros around Lipsi island (Aegean Sea, Greece); the decapod Penaeus Hathor in Aegean waters; the decapod Penaeus aztecus and the nudibranch Melibe viridis in the Dodecanese islands; the finding of Pinctada imbricata radiate in the Mar Grande of Taranto (Ionian Sea, Italy) and the Maliakos Gulf (Greece)

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 theBlack Sea (Sea of Marmara). The new records were reported from 11 countries as follows: Algeria: occurrence of the Africanstriped grunt Parapristipoma octolineatum; Spain: new records of eight uncommon fish species (Gadella maraldi, Hypleurochilusbananensis, Lobotes surinamensis, Parapristipoma octolineatum, Selene dorsalis, Sphoeroides marmoratus, Tetragonuruscuvieri, and Trachyrincus scabrus) from the Spanish Mediterranean; Italy: new record of the football octopus Ocythoe tuberculatafrom the Southern Tyrrhenian Sea; a rare sighting of a juvenile phase of a moray eel of the genus Gymnothorax, tentativelyidentified as Gymnothorax cf. unicolor in the Ligurian Sea; first record of adult Facciola’s sorcerer Facciolella oxyrhynchus inthe Adriatic Sea; occurrence of the tope shark Galeorhinus galeus in the Northern Adriatic Sea; Libya: first confirmed recordof the pen shell Pinna rudis; first documented record of the palaemonid shrimp Brachycarpus biunguiculatus; first record of thefish Sudis hyalina; Malta: new records of Grant’s rockling, Gaidropsarus granti; multiple concomitant reports of the rare hydromedusanspecies 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 Sargassumflavifolium 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 seaslug Placida cremoniana for the easternmost Mediterranean Sea; new record of the yellow-headed goby Gobius xanthocephalusin the Sea of Marmara; Cyprus: first record of the Liechtenstein’s goby Corcyrogobius liechtensteini; an individual of the Yellowfintuna Thunnus albacares captured with handline by an artisanal fisher; Lebanon: an individual of the Black marlin Istiompaxindica captured in a gill ne

New Mediterranean Biodiversity Records (April, 2014)

According to reports, the following 16 species have extended their distribution to other Mediterranean areas or have made a new appearance in other regions. The first category includes the following organisms: The rare and common Indo-Pacific seaweed Codium arabicum (Lebanese coasts), the acari Thalassarachna affinis (Marmara Sea), and the non-indigenous nudibranch Flabellina rubrolineata, which has also been found in many other areas of the Aegean Sea. In addition, the rare sea slug Thecacera pennigera (Piccolo of Taranto), the fangtooth moray Enchelycore anatina (National Marine Park of Zakynthos, Ionian Sea), the carangid Seriola fasciata (Gulf of Antalya), Lagocephalus sceleratus (SE. Ionian Sea), the reticulated leatherjacket Stephanolepis diaspros (Slovenia, N. Adriatic Sea), the marbled stingray, Dasyatis marmorata (NE Levantine), the starry smooth-hound Mustelus asterias (Iskenderun Bay, NE Mediterranean), the cephalopod Ommastrephes bartramii (Ionian Sea) have also been reported. The Atlantic crab Dyspanopeus sayi has expanded to many Italian areas and the blue crab Callinectes sapidus to a lake in N. Greece and in the S. Adriatic Sea. Finally, Farfantepenaeus aztecus has been found in the Ionian Sea, thus showing its wide expansion in the Mediterranean. The larval stages of Faccionella oxyrhyncha have been found, after many years, in the Aegean Sea and the first report of an existence on intersexual acari Litarachna duboscqi in Split(Adriatic Sea) was reported

New Mediterranean biodiversity records (March 2016)

In this Collective Article on “New Mediterranean Biodiversity Records”, we present additional records of species found in the Mediterranean Sea. These records refer to eight different countries mainly throughout the northern part of the basin, and include 28 species, belonging to five Phyla. The findings per country include the following species: Spain: Callinectes sapidus and Chelidonura fulvipunctata; Monaco: Aplysia dactylomela; Italy: Charybdis (Charybdis) feriata, Carcharodon carcharias, Seriola fasciata, and Siganus rivulatus; Malta: Pomacanthus asfur; Croatia: Lagocephalus sceleratus and Pomadasys incisus; Montenegro: Lagocephalus sceleratus; Greece: Amathia (Zoobotryon) verticillata, Atys macandrewii, Cerithium scabridum, Chama pacifica, Dendostrea cf. folium, Ergalatax junionae, Septifer cumingii, Syphonota geographica, Syrnola fasciata, Oxyu- richthys petersi, Scarus ghobban, Scorpaena maderensis, Solea aegyptiaca and Upeneus pori; Turkey: Lobotes surinamensis, Ruvettus pretiosus and Ophiocten abyssicolum. In the current article, the presence of Taractes rubescens (Jordan & Evermann, 1887) is recorded for the first time in the Mediterranean from Italy. The great contribution of citizen scientists in monitoring biodiversity records is reflected herein, as 10% of the authors are citizen scientists, and contributed 37.5% of the new findings.peer-reviewe

Unpublished Mediterranean records of marine alien and cryptogenic species

Good datasets of geo-referenced records of alien species are a prerequisite for assessing the spatio-temporal dynamics of biological invasions, their invasive potential, and the magnitude of their impacts. However, with the exception of first records on a country level or wider regions, observations of species presence tend to remain unpublished, buried in scattered repositories or in the personal databases of experts. Through an initiative to collect, harmonize and make such unpublished data for marine alien and cryptogenic species in the Mediterranean Sea available, a large dataset comprising 5376 records was created. It includes records of 239 alien or cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries surrounding the Mediterranean Sea. In terms of records, the most reported Phyla in descending order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. The most recorded species was Caulerpa cylindracea, followed by Siganus luridus, Magallana sp. (cf. gigas or angulata) and Pterois miles. The dataset includes records from 1972 to 2020, with the highest number of records observed in 2018. Among the records of the dataset, Dictyota acutiloba is a first record for the Mediterranean Sea. Nine first country records are also included: the alga Caulerpa taxifolia var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner shrimp Urocaridella pulchella from Israel; the sponge Paraleucilla magna from Libya and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan Celleporaria vermiformis and the polychaetes Prionospio depauperata and Notomastus aberans from Malta

Spawning habitat and daily egg production of sardine (Sardina pilchardus) in the eastern Mediterranean

Spawning habitats of two eastern Mediterranean sardine, Sardina pilchardus (Walbaum, 1792), stocks ( coastal waters of central Aegean and Ionian Seas) are characterized from daily egg production method (DEPM) surveys conducted during the peak of the spawning period. The latter occurs earlier in the Aegean Sea ( December) than in the less-productive Ionian Sea ( February). Single-parameter quotient analysis showed that the preferred bottom depth for spawning was 40-90 m in both areas but sardine selected sites of increased zooplankton in the Aegean Sea during December and increased fluorescence in the Ionian Sea during February. Estimates of daily egg production (P) and spawning stock biomass ( B) were about four times lower for the Ionian Sea (P 7.81 eggs m(-2), B = 3652 tonnes) than the Aegean Sea (P=27.52 eggs m(-2), B = 16 174 tonnes). We suggest that zooplankton biomass might not be sufficient to support sardine reproduction in the highly oligotrophic Ionian Sea where the very small sardine stock may rely on the late-winter phytoplankton bloom. Actively selecting sites with increased zooplankton or phytoplankton and feeding plasticity (the well-known switching from selective particle feeding to non-selective filter feeding in sardines) are interpreted as adaptations to grow and reproduce optimally at varying prey conditions. Despite differences in temperature and productivity regimes, reproductive performance of sardine in the Ionian Sea was very similar to that in the Aegean Sea during the peak of the spawning period. In comparing adult parameters from DEPM applications to Sardina and Sardinops stocks around the world, a highly significant linear relation emerged between mean batch fecundity ( F) and mean weight of mature female ( W, g) (F = 0.364W, r(2) = 0.98). The latter implies that, during the peak of the spawning period, mean relative batch fecundity (eggs g(-1)) of sardine is fairly constant in contrasting ecosystems around the world