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Biometry and reproductive biology of Pseudonereis anomala Gravier 1901 (Polychaeta: Nereididae) on the Alexandria coast, Egypt

Hamdy R., Dorgham M.M., El-Rashidy H. H., Atta M. M.

Oceanologia

2014

No. 56 (1)

41--58

The biometric characteristics and reproductive biology of the nereid polychaete Pseudonereis anomala were studied monthly from August 2009 to July 2010 at two ecologically different sites (Abu-Qir and El-Mex) on the Alexandria coast, south-eastern Mediterranean Sea. The maximum body length and weight showed different values at the two sites: 9.8 and 11.9 cm, and 0.77 and 1.3 g respectively. The formula of the length-weight relationship indicated allometric growth, whereas the regression equation between length to the 6th segment and weight reflected isometric growth. Immature individuals were the major component of the worm population at the two sites, making up 69.1% at Abu Qir and 66.9% at El Mex; the respective percentages of males and females at these sites were 5.8-8.1% and 22.8-27.3%. Spawning was observed all the year round with female fecundity conspicuously lower at Abu-Qir (annual average: 26556 ± 999 eggs per female) than at El-Mex (annual average: 47955 ± 2916 eggs per female). However, oocyte size was greater at Abu Qir (diameter: up to 250 µm) than at El Mex (diameter: up to 220 µm).

First records of polychaetes new to Egyptian Mediterranean waters

Dorgham M.M., Hamdy R., El-Rashidy H. H., Atta M. M.

Oceanologia

2013

No. 55 (1)

235-267

Nineteen benthic polychaete species were recorded for the first time in the intertidal zone of the Alexandria coast, south-eastern Mediterranean Sea. They belong to Syllidae (7 species), Hesionidae (3 species), Serpulidae (2 species) and 7 other families (one species each). Of these species Eunice miurai Carrera-Parra & Salazar-Vallejo 1998 appears to be new to the Mediterranean Sea, while four of the alien species earlier recorded in the Mediterranean were found for the first time in Egyptian waters: Opisthosyllis brunnea Langerhans 1879, Loimia medusa Savigny 1822, Syllis schulzi Hartmann-Schröder 1960, Phyllodoce longifrons Ben-Eliahu 1972. The newly recorded species demonstrated markedly different patterns of frequency of occurrence and numerical abundance. Spirobranchus triqueter Linnaeus 1758, S. schulzi, L. medusa and Salvatoria clavata Clapare`de 1863 were permanent and abundant species in fouling samples along the Alexandria coast. Saccocirrus papillocercus Bobretzky 1872 persisted in the sediments at two sites, with a much higher count at the stressed one, while Protodrilus sp. inhabited sediments at two other sites throughout the year, sometimes in very high numbers. In addition, the alien species found earlier, Brania arminii Langerhans 1881, Odontosyllis fulgurans Audouin & Milne-Edwards 1833 and O. brunnea Langerhans 1879, were frequently observed along the Alexandria coast.