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This paper reports new records of Didogobius splechtnai Ahnelt et Patzner, 1995 along the French Mediterranean coast. Additional comments on older underwater observations of D. schlieweni Miller, 1993 are also provided. The status of rarity of these two species is discussed. D. splechtnai is probably regularly distributed in the north-western and eastern Mediterranean where suitable habitats are available but both species are considered as rare (D. splechtnai) to very rare (D. schlieweni).
Background. This study was initiated by the first observations of a coastal and benthic Atlantic fish species—Parablennius pilicornis (Cuvier, 1829) on the southern coasts of France. This fish has been recorded in the Mediterranean Sea since 1963, until recently colonizing its entire western part as well as the Adriatic Italian coasts. The aim of this study is to analyse and understand the dynamics of this invasion of P. pilicornis and to report its most recent sightings along the Provencal coast, France. Materials and Methods. The data on the geographic distribution of P. pilicornis were either extracted from the relevant literature (majority of records) or contributed by the present authors. For the French coast, particularly the coast of Provence, the latter were data from underwater visual censuses, conducted during various studies or monitoring programs. The data were critically selected, organised, and analysed. Results. Two dispersal pathways seem to have been followed by P. pilicornis. The first follows the coast of Morocco, Algeria, and Italy. The second pathway goes through the Spanish and French coasts. The meeting point of these two ways may be located on the coast of Provence, where we lastly observed this species in 2006. The emergence of P. pilicornis in the Mediterranean Sea corresponds clearly to a marginal dispersal. Colonization of the western Mediterranean took 43 years. Conclusion. Since P. pilicornis is already present on the Italian coast of the Adriatic Sea, the colonization of the eastern Mediterranean seems imminent. Global change, including rising temperatures, seem to be a factor promoting the repartition area of this fish with tropical affinities.
Three specimens of silver-cheeked toadfish, Lagocephalus sceleratus (Gmelin, 1789), were caught on eastern coasts of Algeria during the winter of 2013–2014. This is the first record of this invasive species from Algeria, providing further evidence of its occurrence along north-African coasts and confirming its entry into the Western basin of the Mediterranean. The human-health implications of this toxic fish in this region are discussed.
The barred knifejaw, Oplegnathus fasciatus (Temminck et Schlegel, 1844), a species native to the North Western and Eastern Central Pacific, is recorded from the central Mediterranean for the first time. Two individuals were photographed within a month of each other in Grand Harbour and in Marsamxett Harbour, Malta. It seems likely that the fish were introduced by shipping and different scenarios how this may have happened are discussed.
Background. Bastard grunt, Pomadasys incisus (Bowdich, 1825), is reported as a ell-established species in the Mediterranean Sea. Although bastard grunt has rapidly expanded its area of distribution in the Mediterranean, there is no information about its age and growth. The aim of this study was to provide data about growth, condition, and first sexual maturity of the species in order to contribute to a better management of its fishery. Materials and methods. A total of 515 specimens of bastard grunt were caught in the Gulf of Tunis. The age was determined from otoliths. Length–weight relation, von Bertalanffy equation, and growth rate were employed to evaluate the fish growth. Also the condition factor and length at first sexual maturity were calculated. Results. In the Gulf of Tunis population, females were significantly predominant and the overall sex ratio (M : F) reached the value of 1 : 2.17. The two sexes showed a positive allometric growth. The marginal increment analysis validated the annual deposition of one single annulus in the winter. Growth in (total) length (TL) was approximately 65% during the first year of life. The von Bertalanffy growth equation was TL = 23.9 × (1 – e–0.186 × (t + 4.62)). The somatic condition of fish increased markedly during the late spring and summer. Length at first sexual maturity of the bastard grunt was 16.6 cm for males and 16.8 cm for females, which correspond to an age of about 2 years. Conclusion. The rapid growth during the first year of life, the early maturity and the moderately short life cycle contribute to the relatively fast spreading of the species.
The first records of Lampris guttatus in the Mediterranean Sea date back to 1807. Yet, until now it has been considered as a rare species (less than 25 specimens recorded in the literature). Since 2008, at least 23 specimens have been fished or observed along the French Mediterranean coast. In this paper, we present an updated review of records in the Mediterranean and discuss the possible link with the present sea water warming. We hypothesise that the recentMediterranean specimens could come from the Atlantic, throughout the Gibraltar Strait, following a northward migration along the Northeast Atlantic coast due to present global warming.
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