•Genetic diversity was high for resident goatfish species in Egypt but lower for the migrant species.•No genetic partitioning for all three goatfish species based on AMOVA and network analyses.•The ...Delta Nile outflow may not pose a significant barrier to larval dispersal for goatfish.
We examined the genetic diversity and connectivity of two indigenous Mediterranean goatfish species (Mullus barbatus and M. surmuletus), and a Lessepsian migrant species (Upeneus moluccensis), across the Nile Delta outflow using two mitochondrial DNA markers (COI and cyt b). Genetic diversity was high for the two Mediterranean species but relatively lower for the migrant species, suggesting founder effects after invasion from the Red Sea. Confirmation of this hypothesis, however, would require comparison with populations of origin in the Red Sea and the broader Indo-West Pacific. AMOVA and network analyses revealed no genetic partitioning for all species, indicating that the Nile outflow does not currently, and may not have historically, posed a significant barrier to larval dispersal in these goatfish, despite a present-day temperature and salinity gradient along the Mediterranean coastline of Egypt.
The blue swimming crab Portunus segnis (Forskål, 1775) (family Portunidae) is one of the earliest Lessepsian invaders of the Mediterranean Sea and has been recorded for several decades in various ...Mediterranean areas. However, its presence on the southeastern Tunisian coast is very recent. This study describes the reproductive biology of the species in the Gulf of Gabes, including sex ratio, ovarian maturation, size at sexual maturity, spawning season and fecundity. Samples for biological investigation were collected from the commercial catches of trawlers and artisanal fishing units, from January to December in 2018. A total of 2 762 specimens, ranging from 19 to 158 mm carapace width (CW) and 0.638 to 356.109 g body weight (BW), were analysed. Females outnumbered males by 1.3 to 1 (1 581 vs 1 181 individuals). Sexual maturity was classified into five stages for females and three stages for males, based on visual observation of the colour and shape of the gonads. Spawning occurred three times during the year, with the first peak in May, the second in July, and the third-the most intensive peak-in October-November. Size at sexual maturity was 93.1 mm CW for males, and 93.6 mm CW for females. Females carried 142 242-2 640 080 eggs on their abdomen, with a positive linear relationship between fecundity and CW. The data presented in this study should be useful not only to detect variations in the reproductive cycle of P. segnis between regions but also to ensure sustainable management of the new fishery for the species in Tunisian waters.
In the present study, one juvenile specimen of redcoat Sargocentron rubrum (Forsskål, 1775) was first reported from the Mediterranean coast of Turkey with a visual record during an underwater survey ...conducted from the coast of Arsuz (Konacik), Iskenderun Bay, at a depth of 3 m, on September 11, 2018. The Family Holocentridae is currently represented in the Mediterranean by seven species, all exotic, six of them originate in the Red Sea (Lessepsian migrants) and one originates from the Atlantic.
En el presente estudio, un espécimen juvenil de candil rojo Sargocentron rubrum (Forsskål, 1775) fue reportado por primera vez en la costa mediterránea de Turquía, mediante un registro visual durante un estudio submarino realizado desde la costa de Arsuz (Konacik), bahía de Iskenderun, a una profundidad de 3 m, el 11 de septiembre de 2018. La Familia Holocentridae está representada actualmente en el Mediterráneo por siete especies, todas exóticas, seis de ellas originarias del Mar Rojo (migrantes lessepsianos) y una originaria del Atlántico.
On 16 June 2022, two specimens of
Pomacanthus maculosus
(Forsskål, 1775) were observed in the Syrian marine waters. One specimen was captured and classified, measured, preserved in formaldehyde and ...deposited at Tishreen University. It is a second substantiated record in the Levant Basin, and the first for the Syrian coast. The successful establishment of a viable population of
P. maculosus
in the Mediterranean Sea remains a suitable hypothesis which cannot be totally ruled out.
Dana 16. lipnja 2022. godine, dva primjerka vrste
Pomacanthus maculosus
(Forsskål, 1775) zabilježena su u sirijskim morskim vodama. Jedan primjerak je uhvaćen, identificiran, izmjeren, sačuvan u formaldehidu te pohranjen na Sveučilištu Tishreen u Siriji. To je drugi potvrđeni nalaz ove vrste za područje Levanta te prvi za sirijske vode. Uspješna uspostava održive populacije vrste
P. maculosus
u Sredozemnom moru ostaje prikladna hipoteza koja se ne može potpuno odbaciti.
Climate change fuels invasions of plant species and displacement of local plants. Little is known about the ecophysiological adaptation of the invasive species, and their ability to cope with the ...changing conditions in their new habitat. Halophila stipulacea, a tropical seagrass native to the Gulf of Aqaba (GoA; northern Red Sea), became a Lessepsian migrant spreading within the eastern Mediterranean where it could potentially outcompete local species. We analyzed temperature records in the last 35 years and show that water temperature has increased faster in the eastern Mediterranean Sea compared to GoA, suggesting that H. stipulacea’s invasive success is associated with adaptation to thermal warming. Furthermore, we compared the responses of native (Eilat, Israel) and invasive (Limassol, Cyprus) H. stipulacea plants to current (26oC) and predicted thermal maxima (29℃ and 32℃) in a controlled experimental microcosm. Morphological and photo-physiological results showed negative effects of heat stress on the native plants while un-affected/ or even enhanced performance in their invasive counterparts. Gene expression, studied for the 1st time in H. stipulacea, pointed to differences in the molecular responses of two populations to thermal stress. Results predict that sea warming will cause vast reductions in H. stipulacea meadows growing in the GoA while sea warming will facilitate H. stipulacea’s spread within the Mediterranean Sea.
The flat needlefish Ablennes hians was recorded for the first time from the coast of Turkey in the eastern Mediterranean. Two specimens were captured, one in May 2021 and the second in April 2022. ...One of the specimens was preserved and deposited in fish collection, while only the photograph of the other was obtained.
Plosnata iglica Ablennes hians po prvi put je zabilježena u vodama Turske u istočnom Sredozemnom moru. Dva primjerka su uhvaćena, jedan u svibnju 2021. godine, a drugi u travnju 2022. godine. Jedan je primjerak sačuvan u ihtiološkoj zbirci, dok je drugi primjerak samo fotografiran.
Halophila stipulacea is a dioecious seagrass that colonised the Mediterranean basin probably following the opening of the Suez Canal in 1869. We investigated its occurrence in the southern ...Mediterranean. This was done by conducting targeted surveys in two countries (Tunisia and Libya) and compiling existing information from former research. Four new meadows of H. stipulacea were found in the study area: Al-wahesh Lagoon and Tobrouk Bay in Libya, and Kerkennah Island-Allama and Cap Monastir in Tunisia. The new record in Cap Monastir (Tunisia) documents a displacement of approximately 150 km north of the previous limit of H. stipulacea in the southern Mediterranean, which probably represents the westernmost extension of H. stipulacea’s distribution 3000 km west along the coast from the site of first colonisation at the mouth of the Suez Canal in Port Said. In the Cap Monastir meadow, the shoot density (±SD) was 9900±3509 m-2and the leaf area index was 3.15±0.5 m2m-2. In Libya, a small meadow of H. stipulacea was documented for the first time in Tobrouk Bay, with an estimated shoot density of 476±83 m-2.
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