Spatiotemporal patterns of phenology of the alien Phaeophyceae Sargassum muticum on the Atlantic coast of Morocco

The present study focused on the dynamics of the phenology and life cycle of the Phaeophyceae invader Sar-gassum muticum at three sites on the Atlantic coast of Morocco over a period of two years (2013 and 2014). The results showed that S. muticum has two distinct growth phases; one with slower growth in winter followed by one with faster growth in spring-early summer, when the species exhibited high elongation and branching activities with thalli length ranging from 1 to more than 5 m depending on the study site. The site S1, with a rocky substratum covered by submerged sands, promotes thalli elongation, with maximum lengths of 643.33±11.10 cm recorded in July. At the rocky sites (S2 and S3), the maximum length of the seaweed depends on the pools’ depth. Although the elongation of thalli is enhanced by the water body depth, the settlements’ density (5-48 ind. m–2) seems to be mainly related to the nature of the substrate. The ma-turity index progressively increases from spring to early summer, when it reaches the highest values. S. muticum seems to be more abundant and more easily acclimated in shallow rockpools (sufficiently lighted and semi-exposed to wave action at the mid and lower tidal levels) than in protected sandy bottom sites with low hydrodynamic forces.info:eu-repo/semantics/publishedVersio

The invasive Atlantic blue crab Callinectes sapidus Rathbun, 1896 expands its distributional range southward to Atlantic African shores: first records along the Atlantic coast of Morocco

The occurrence of the exotic Atlantic blue crab Callinectes sapidus Rathbun, 1896 (Crustacea: Decapoda: Portunidae) is reported for the first time from the Moroccan Atlantic coast. Working with local fishermen, we gathered 160 records of the Atlantic blue crab from several estuarine, coastal and marine areas, in the period between June and August 2021. These new records confirm its establishment in the Atlantic coasts of North Africa, suggesting a southern range expansion. These findings, likely exacerbated by growing populations along the Atlantic coast of Morocco and temperate coastal waters, provide new insights into the invasion dynamics of this species in the northeast Atlantic Ocean.info:eu-repo/semantics/publishedVersio

Record of the first Pleonexes species (Crustacea: Amphipoda: Ampithoidae) in Moroccan waters: Pleonexes gammaroides Spence Bate, 1857

The ampithoid amphipod crustacean Pleonexes gammaroides Spence Bate, 1857 is reported from Morocco (northeastern Atlantic Ocean) for the first time, where it is the only representative of the genus Pleonexes Spence Bate, 1857 so far. Specimens were collected from the upper fringe of the infralittoral zone (including low intertidal) of El Jadida coastline associated with the holdfasts of the kelp Saccorhiza polyschides (Lightfoot) Batters (Phaeophyceae), colonising the sublittoral fringe in the southernmost distribution limit (Morocco). This finding updates the known geographical distribution of P. gammaroides in northern Africa and northeastern Atlantic. Some ecological and distributional details of this amphipod species are briefly discussed here.National Centre for Scientific and Technical Research (CNRST), Morocco 5UCD2017, AGA- KHAN Foundation under the project MARAFRICA AGA-KHAN/540316524/2019info:eu-repo/semantics/publishedVersio

The Invasive Seaweed <i>Agarophyton vermiculophyllum</i> from Oualidia Lagoon (Northwestern Moroccan Atlantic Coast) as a Source of Agar: Yield, Chemical Characteristics, and Rheological Properties

Agar is a hydrophilic biopolymer extracted from red seaweed. This phycocolloid consists of two components: agarose and agaropectin. In the present work, agar extracted from the invasive red seaweed Agarophyton vermiculophyllum was characterized using physical, chemical, and spectroscopic analyses to investigate the effect of alkaline pretreatment on agar properties. Two extraction conditions, native and alkali-pretreated agars, were comparatively studied. The native yield (28.4 ± 0.9%) was higher than that of the alkaline-pretreated agar (20.4 ± 0.8%). The alkali-pretreated agar showed higher gel strength (763.8 ± 57.0g cm−2), gelling (36.5 ± 0.9 °C), and melting (83.2 ± 0.6 °C) temperatures and increased 3,6-anhydrogalactose (26.2 ± 1.9%) and decreased sulfate contents (6.2 ± 0.8%) compared with native agar (gel strength: 204.8 ± 17.10g cm−2, gelling temperature: 29.5 ± 0.9 °C, melting temperature: 73.4 ± 0.7 °C, 3,6-AG content: 13.8 ± 0.7%, sulfate content: 10.5 ± 0.5%). The alkaline pretreatment improved the agar’s gelling properties and significantly influenced its chemical properties. In view of the obtained results, A. vermiculophyllum might potentially be thought of as a viable source for the agar industry in Morocco, serving as a local source of agar