Distribution patterns of shallow water polychaetes (Annelida) along the Alexandria coast, Egypt (eastern Mediterranean)

Abstract

Shallow hard bottom and intertidal soft bottom polychaete assemblages of the Alexandria coast, south-eastern Mediterranean (Levantine Sea), were studied during a complete annual cycle in order to analyze spatial temporal patterns of variation in assemblages, and relevant factors related to polychaete distribution. The present study recorded a total of 73 species, belonging to Syllidae (22 species), Nereididae (9 species), Serpulidae (6 species), Eunicidae (5 species) and another 19 families. The assemblages experienced pronounced spatial and temporal variation throughout the study area, but spatial variation appeared more important in determining the observed patterns. Polychaete distribution related to variation of grain size and sessile macrobenthos cover suggesting that these structural variables accounted more than the physical-chemical ones (namely BOD, dissolved oxygen, organic carbon, organic matter, salinity, temperature, pH) in influencing the patterns of assemblage distribution. A total of 9 alien polychaete species were found solely on hard substrata, of which Pseudonereis anomala and Linopherus canariensis formed dense population in the area. The present study is the south-eastern-most one dealing with the ecology and distribution patterns of hard bottom polychaetes from the Mediterranean Sea, as well as one of the few studies dealing with intertidal soft bottom polychaetes in the Levant Basin.

Cosmopolitan or Cryptic Species? A Case Study ofCapitella teleta(Annelida: Capitellidae)

“…Considering the shared COI haplotype between Massachusetts and Ainan, and the short planktonic larval duration (several hours; Blake et al, 2009), the broad distribution of C. teleta is likely due to anthropogenic dispersal, e.g., via ships' ballast water (e.g. Chu et al, 1997;Dorgham and Hamdy, 2015). This may also be the case for individuals in Clade 7 (Fig.…”

Distribution and functional traits of polychaetes in a CO2 vent system: winners and losers among closely related species

“…Musco 2012 and references therein), with variation in their distributions determined by substrate type as well as the quality and quantity of algal and sessile invertebrate cover (e.g. Dorgham et al 2014). Macroalgae and other sessile invertebrates influence the diversity and abundance patterns of the associated zoobenthic communities by structuring rocky reef habitats at small scales (Jacobi & Langevin 1996, Parker et al 2001, Chemello & Milazzo 2002 and polychaete assemblages (Abbiati et al 1987, Giangrande 1988, Sardá 1991, Tena et al 2000, Fraschetti et al 2002, Giangrande et al 2003, Antoniadou et al 2004, Serrano et al 2006, Dorgham et al 2014.…”

“…These different individual responses of apparently related polychaete species suggest that the effects of OA on natural assemblages might be more complex than expected. Given the importance of algae and sessile macrobenthos for polychaete ecology (Giangrande 1988, Giangrande et al 2003, Antoniadou & Chintiroglou 2006, Dorgham et al 2014, understanding how polychaete assemblages vary with other important habitat-forming species along a decreasing pH gradient is crucial to disentangle the direct effects of OA from indirect effects via habitat modification.…”

Reducing the data-deficiency of threatened European habitats: Spatial variation of sabellariid worm reefs and associated fauna in the Sicily Channel, Mediterranean Sea

“…All the sampled locations, in particular, presented sabellariid reefs interspersed within a predominant sandy bottom, but these were close to a P. oceanica meadow at Triscina and to a breakwater rocky barrier at Donnalucata, i.e., markedly different habitats that are likely to provide different pools of colonizers to adjacent Sabellaria-associated assemblages. For example, shallow hard substrates in the Mediterranean Sea are reported to host diverse and abundant assemblages of syllid polychaetes (Chatzigeorgiou et al, 2012;Musco, 2012;Dorgham et al, 2014), a feature that could have contributed to the larger abundance of S. pulvinata, the most numerous syllid in this study, at Donnalucata compared to Triscina. Concomitantly, significant among-locations variation in the distribution of reefassociated fauna could also be driven by patterns of dispersal of organisms varying over the same scale (e.g., Johnson et al, 2001;Fraschetti et al, 2005b).…”