Oxynotus centrina (Oxynotidae) from the Tunisian coast (Mediterranean Sea)

The authors report in the present paper the capture of two specimens of a rare shark, angular rough shark Oxynotus centrina (Linnaeus, 1758), from the northern coast of Tunisia. A first specimen was a juvenile female caught off Ras Jebel, the second specimen was a juvenile male caught off Kelibia. These captures occurred after two decades in the area where it appears that the species is not totally exctincted. The Mediterranean distribution of O. centrina appears to be different according to the region, absent from the coast of France, specimens were still sporadically caught in the Adriatic Sea, and mainly in the Aegean Sea and the eastern Basin

Spolna zrelost, stanište i ekološki aspekti rasprostranjenosti jednakonošca Sphaeroma venustissimum u tuniskim vodama

A total of 4665 specimens of Sphaeroma venustissimum Monod, 1931 were collected between February 2012 and January 2013, in Tunis Southern Lagoon, a brackish area located in northern Tunisia. This species was mainly recorded in the Atlantic Ocean and recently extended its natural range toward the southern Mediterranean Sea. Biological and ecological traits were not available to date with special regard to its native and recipient habitat. S. venustissimum isopoda inhabits area below stones covered by biofouling and empty nests of barnacles. The species occurs and reproduces in Tunis Southern Lagoon throughout the year with a peak in early spring and late summer. Males significantly outnumbered females during high reproductive activity period (May - July). The first gravid female was observed at 7 mm and the fecundity ranged between 6 and 17 eggs. Among the gravid females, a significant relationship was noted between the importance of brood versus total body length for all ovigerous female cohorts. The recruitment occurred throughout the year with a winter peak. S. venustissimum have established a sustainable population in Tunisia and have spread into the wild in its new host area.Ukupno 4665 primjeraka Sphaeroma venustissimum Monod, 1931., prikupljeno je između veljače 2012. i siječnja 2013. u tuniskoj Južnoj laguni, u bočatoj vodi koja se nalazi u sjevernom Tunisu. Ova vrsta je uglavnom zabilježena u Atlantskom oceanu, te je nedavno proširila svoj prirodni raspon prisutnosti prema južnom Sredozemnom moru. Do danas nisu bile dostupne biološke i ekološke osobitosti ovog izopoda s posebnim osvrtom na stanište i primatelje. Izopod S. venustissimum nastanjuje se ispod kamenja prekrivenih obraštajem i praznim gnijezdima rakova vitičara ispitivanja stabala kao staništa. Vrste se pojavljuju i reproduciraju u Južnoj laguni u Tunisu tijekom cijele godine s vrhuncem u rano proljeće i kasno ljeto. Mužjaci su brojčano značajno nadmašili ženke tijekom razdoblja visokog reproduktivnog djelovanja (svibanj - srpanj). Prva promatrana gravidna ženka je bila veličine 7 mm, a plodnost je iznosila između 6 i 17 jaja. Među gravidnim ženkama, zabilježena je značajna veza između važnosti legla u odnosu na ukupnu dužinu tijela za sve ženke s prekomjernom veličinom. Novačenje se odvijalo tijekom cijele godine s vrhuncem u zimskom periodu. Uspostavljene su održive populacije izopoda S. venustissimum u Tunisu, te su se proširile u divljinu kao svom novom prostoru domaćina

Spolna zrelost, stanište i ekološki aspekti rasprostranjenosti jednakonošca Sphaeroma venustissimum u tuniskim vodama

A total of 4665 specimens of Sphaeroma venustissimum Monod, 1931 were collected between February 2012 and January 2013, in Tunis Southern Lagoon, a brackish area located in northern Tunisia. This species was mainly recorded in the Atlantic Ocean and recently extended its natural range toward the southern Mediterranean Sea. Biological and ecological traits were not available to date with special regard to its native and recipient habitat. S. venustissimum isopoda inhabits area below stones covered by biofouling and empty nests of barnacles. The species occurs and reproduces in Tunis Southern Lagoon throughout the year with a peak in early spring and late summer. Males significantly outnumbered females during high reproductive activity period (May - July). The first gravid female was observed at 7 mm and the fecundity ranged between 6 and 17 eggs. Among the gravid females, a significant relationship was noted between the importance of brood versus total body length for all ovigerous female cohorts. The recruitment occurred throughout the year with a winter peak. S. venustissimum have established a sustainable population in Tunisia and have spread into the wild in its new host area.Ukupno 4665 primjeraka Sphaeroma venustissimum Monod, 1931., prikupljeno je između veljače 2012. i siječnja 2013. u tuniskoj Južnoj laguni, u bočatoj vodi koja se nalazi u sjevernom Tunisu. Ova vrsta je uglavnom zabilježena u Atlantskom oceanu, te je nedavno proširila svoj prirodni raspon prisutnosti prema južnom Sredozemnom moru. Do danas nisu bile dostupne biološke i ekološke osobitosti ovog izopoda s posebnim osvrtom na stanište i primatelje. Izopod S. venustissimum nastanjuje se ispod kamenja prekrivenih obraštajem i praznim gnijezdima rakova vitičara ispitivanja stabala kao staništa. Vrste se pojavljuju i reproduciraju u Južnoj laguni u Tunisu tijekom cijele godine s vrhuncem u rano proljeće i kasno ljeto. Mužjaci su brojčano značajno nadmašili ženke tijekom razdoblja visokog reproduktivnog djelovanja (svibanj - srpanj). Prva promatrana gravidna ženka je bila veličine 7 mm, a plodnost je iznosila između 6 i 17 jaja. Među gravidnim ženkama, zabilježena je značajna veza između važnosti legla u odnosu na ukupnu dužinu tijela za sve ženke s prekomjernom veličinom. Novačenje se odvijalo tijekom cijele godine s vrhuncem u zimskom periodu. Uspostavljene su održive populacije izopoda S. venustissimum u Tunisu, te su se proširile u divljinu kao svom novom prostoru domaćina

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

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia).peer-reviewe

Unusual record of longjaw snake eel, Ophisurus Serpens (Osteichthyes: Ophichthidae) in Tunisian waters (Central Mediterranean)

The present paper represents an additional and unusual record of the long jaw snake eel, Ophisurus serpens (Osteichthyes: Ophichthidae) in the Lagoon of Bizerte, a brackish area located in northern Tunisia. The specimen measured 1890 mm in total length and weighed 1096 g, it is described in the present paper including morphometric measurements and meristic counts. This specimen is the third well-documented record of O. serpens in the area, and the second in a peri-Mediterranean lagoon. This unusual capture is commented and discussed, and the use of the local ecological knowledge allows to assess the status of O. serpens in the area, where further records are needed prior to conclude about a successful establishment

Record of a critically endangered skate, Leucoraja melitensis (Chondrichthyes: Rajidae) from Tunisian Coast (Central Mediterranean)

The authors report the capture of a specimen of the Maltese skate Leucoraja melitensis (Clark, 1926) from the northern coast of Tunisia. The specimen was a juvenile female having 270 mm in total length, 136 mm in disc width, and weighing 80.2 g. The species was previously common in the area, but at present it is becoming very rare indicating a drastic decline as in the other Mediterranean areas where it was found. Such parameter explained why L. melitensis is considered as species critically endangered

A shoal of bluntnose sixgill shark Hexanchus griseus (Chondrichthyes: Hexanchidae) from the Tunisian coast (Central Mediterranean)

This paper presents the unusual capture of a shoal of Hexanchus griseus in the Strait of Sicily, close to northern Tunisia. In all, 21 specimens were collected. Their Total Length ranged between 180 and 220 cm, and Total Body Weight between 90 and 120 kg. The distribution of the species off the Tunisian coast and the conditions of the capture are discussed

Unusual and substantiated records of Heptranchias perlo (Chondrichthyes: Hexanchidae) in the N-E Tunisian Waters (Central Mediterranean Sea)

The present paper report unusual and additional records of sharpnose sevengill shark Heptranchias perlo (Bonnaterre, 1788) from the northeastern Tunisian waters. Four specimens were collected in the Gulf of Tunis and two specimens off Bizerte. The specimens were measured for total length and weighed. The specimens from Bizerte were described in the present paper including morphometric measurements and tooth counts. These captures were carried out at lower depth that it was usually the case and showed that the specimens migrated southward, where a viable population is probably established

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.JRC.D.2-Water and Marine Resource