Megaluropus massiliensis Ledoyer, 1976

Megaluropus massiliensis Ledoyer, 1976 View in CoL

Megaluropus massiliensis View in CoL is an endemic Mediterranean species that has also colonized the Black Sea ( Sorbe et al., 2002; Karaçuha et al., 2009; Mülayim, 2021; Grinstov, 2022). It has been recorded in Algeria, Corsica, France, Italy, Israel, Greece, Morocco, Spain, Tunisia and Turkey ( León and Corrales, 1995; Conradi & López-González, 1999; Sánchez-Jerez et al., 1999; San Vincente and Sorbe, 1999; Sorbe et al., 2002; Scipione et al., 2005; Kirkim et al., 2006; Sezgi̇n and Katağan, 2007; Luís, 2007; Karaçuha et al., 2009; Vázquez-Luis et al., 2009; de-la-Ossa-Carretero et al., 2010, 2012; Lorenti et al., 2011; Bakir, 2012; Lattanzi et al., 2013; Bakir & Katağan, 2014; Guerra- García et al., 2014; Çinar et al., 2015; Mülayim et al., 2015a,b; Maidanou et al., 2017, 2021; Zakhama-Sraieb et al., 2017; Targusi et al., 2019; Navarro-Barranco et al., 2020; Bakalem et al., 2024; Saenz-Arias et al., 2024).

This amphipod is a fossorial filter feeder species (de-la-Ossa-Carretero et al., 2012), and it is also an important component of the hyperbenthic fauna of surface sandy substrates ( León & Corrales, 1995; Galparsolo, 1999). Indeed, M. massiliensis View in CoL commonly colonizes fine sand, very fine sand, muddy sand and, less commonly, mud ( Conradi and López-González, 1999; de-La-Ossa-Carretero et al., 2010; Targusi et al., 2019; Mülayim, 2021). In some studies, this species has been observed in association with Spisula subtruncata View in CoL sand ( Mülayim et al., 2015a) and Phaseolina sludge zoocenosis (Sezgi̇n and Katağan, 2007). Megaluropus massiliensis View in CoL has also been observed in relation to shallow-water phanerogam meadows, such as Posidonia oceanica , Cymodocea nodosa , Zostera marina View in CoL and Zostera noltii View in CoL ( Sánchez-Jerez et al, 1999; San Vincente and Sorbe, 1999; Karaçuha et al., 2009; Vázquez-Luis et al., 2009) and with rocky substrates colonized by photophilic macroalgae ( Navarro-Barranco et al., 2020). Some studies have shown that this species also inhabits areas characterized by the presence of the caulerpaces Caulerpa racemosa and C. prolifera ( Luís, 2007; Vázquez-Luis et al., 2009; Lorenti et al., 2011; Maidanou et al., 2017, 2021).

This megaluropid is most abundant in shallow coastal waters between 1 and 10 m ( León & Corrales, 1995; Mülayim et al., 2015a; Maidanou et al., 2017; Saenz-Arias et al., 2024) but some authors have reported it at greater depths up to about 50 m ( Scipione et al., 2005; Conradi and López-González, 1999; Lattanzi et al., 2013).

Ecologically, M. massiliensis was considered particularly sensitive to pollution and organic enrichment (de-la-Ossa-Carretero et al., 2012; Çinar et al., 2015). However, Lattanzi et al. (2013) observed that this amphipod is tolerant to the increase of fine sediment in suspension/deposition. Megaluropus massiliensis feeds on suspended detritus and planktonic crustaceans ( Guerra-García et al., 2014); it is most active at night and can be sampled using light traps ( Saenz-Arias et al., 2024), indicating that it probably moves vertically along the water column.

Our analyses revealed the presence of 468 individuals exclusively on soft sandy bottoms, distributed at depths between 7.8 and 12.81 m. Megaluropus massiliensis was found particularly numerous within Haifa Bay. This species demonstrated low abundances along the entire southern coast of Israel, with two notable peaks in abundance at sites H13 and H28.