Biometry, growth, survivorship, reproduction and productivity have been studied in many different polychaetes in different seas, for example, in Pectinaria koreni ( Nicolaidou 1983), Eupolymnia crescentis, Neoamphitrite robusta, Thelepus crispus and Ramex californiensis ( McHugh 1993), Eunice fucata, E. insularis, E. cf. ornata, E. rubra, and Eunice sp. ( Costa-Paiva & Paiva 2007), Namanereis littoralis ( Ezhova 2011) and Marphysa MG 132 sanguinea ( El Barhoumi et al. 2013). Furthermore, laboratory biological studies have

been carried out on cultures of Neanthes arenaceodentata, Platynereis dumerilii and Nereis virens ( Reish, 1985, Jha et al., 1996 and Olive, 1999), while field studies were done on the cryopreservation of polychaete larvae ( Olive & Wang 1997), growth and reproduction in captivity ( Fidalgo e Costa, 1999 and Reish et al., 2009), spawning ( Watson et al., 2003 and Watson et al., 2005), sex pheromones ( Bartels-Hardege et al. 1996), breeding and optimisation of the growth process (cf. Olive 1999), and biometry and population structure ( Ménard et al., 1989, Omena and Amaral, 2000 and Dağli et al., 2005). Nereids are important prey for many crustaceans and fish (Arias & Drake 1995), and many of them are widely

used as fishing bait in the sea angling sport and leisure industry in different countries (Luis and Passos, 1995, Olive, 1999, Fidalgo e Costa, 1999, Dağli et al., 2005, Cunha et al., 2005 and Younsi MDV3100 et al., 2010). Although numerous studies have been done on the identification, abundance and distribution of polychaetes off the Egyptian Mediterranean coast (Dorgham et al. 2013), very Celecoxib little attention has been drawn to their biometry and reproductive biology. Pseudonereis anomala Gravier 1901 is a commercially important nereid polychaete in Egypt, where it

is usually collected by bait diggers and sold as live bait to fishermen and sea anglers. It is a lessepsian species that has acclimated well to the eastern Mediterranean ( Çinar & Ergen 2005) and has become one of the most important invasive polychaetes in the shallow-water benthic communities of the eastern Mediterranean in general ( Çinar & Altun 2007) and along the Alexandria coast (Egypt) in particular ( Hamdy 2008). The biometry and reproductive biology of P. anomala have never been studied in marine habitats anywhere in the world, except for the investigations into its reproduction and feeding behaviour off the coast of Turkey ( Çinar and Ergen, 2005 and Çinar and Altun, 2007). In Egyptian waters, one study was carried out on the spermatogenesis of Halla parthenopeia ( Abd-Elnaby 2009) and another one on the gametogenesis and spawning of Spirobranchus tetraceros ( Selim et al. 2005).