Distribution and life cycle of the North American Spionid polychaeteMarenzelleria viridis (Verrill, 1873) in the Ems estuary

Abstract

In 1983 the first specimens of the North American spionid polychaete Marenzelleria viridis were found along the European mainland shore in the Ems estuary. Since then, this polychaete has spread over several estuaries around the North Sea and the Baltic. In the inner part of the Ems estuary juveniles were predominantly present in muddy sediments high in the intertidal zone; in more sandy sediments at higher salinities juveniles and adults co-occured. Detailed information was obtained at a muddy and at a sandy station.Gametes were present in the coelomic fluid from November through March. In May new recruits were found in the sediment samples, reaching densities of over 105 m -2 at the muddy station, and c. 2000 m -2 at the sandy station. During summer, densities decreased at the muddy station, coinciding with a density increase at the sandy station, suggesting migration of juveniles from a nursery to the adult habitat. Cage experiments showed that the decrease of juveniles at the muddy station could be attributed to migration and not to mortality due to predation.At the sandy habitat palps and anterior parts of M. viridis made up 4-11% of the stomach content of juvenile plaice (Pleuronectes platessa). In juvenile flounder (Platichthys flesus) only in April c. 10% of the stomach content consisted of M. viridis. During 1983During -1990 increasing densities of M. viridis at the sandy habitat coincided with a reduced abundance of Nereis diversicolor, however, this inverse relationship was not found to be statistically significant. Density fluctuations of M. viridis and Corophiurn volutator showed a significant positive relationship, the cause of which is not yet understood.

Are similar worms different? A comparative tracer study on bioturbation in the three sibling species Marenzelleria arctia, M. viridis, and M. neglecta from the Baltic Sea

“…The computed tomographic scan confirmed that the apparent dense network resulted from the multiplicity of burrows and that M. arctia likely construct individual, unbranched and twisted burrows of , 0.5 mm diameter that are U shaped. In general, shape and depth of burrows of both M. viridis (Essink and Kleef 1988;Quintana et al 2011) and M. neglecta (Zettler et al 1994) were similar, building L-, J-, or I-shaped burrows to a sediment depth of 35 cm with a mean diameter of 2 mm and clearly differed from those of M. arctia. Thus, these sibling species can be distinguished from M. arctia according to their burrows, and the predicate ''deep-burrowing'' species may be applicable only for M. viridis and M. neglecta.…”

“…include facultative deposit feeding and suspension feeding (Fauchald and Jumars 1979;Dauer et al 1981;Sikorski and Bick 2004), although for M. arctia no information is available. M. neglecta (Zettler et al 1994) and M. viridis (Essink and Kleef 1988;Quintana et al 2011) are known to construct L-, J-, or I-shaped, unbranched mucus-lined burrows to a sediment depth of 25-35 cm with a mean diameter of 2 mm. In contrast, M. arctia creates J-, Y-, or U-shaped burrows with a thin transparent membrane lining to a maximum depth of 6-8 cm (Hietanen et al 2007;own observation).…”

Macrobenthic community response to the Marenzelleria viridis (Polychaeta) invasion of a Danish estuary

“…Species of the genus Marenzelleria have the required tolerance (Hahlbeck et al 2000, Blank et al 2004) to withstand salinity fluctuations and exposure to anoxia or even sulfidic events that are common in Danish estuaries (Conley et al 2000). Furthermore, it has a high reproductive capacity (Essink & Kleef 1993) …”

Long-term changes in intertidal estuarine diatom assemblages related to reduced input of organic waste

“…In 1988, near the mouth of the WWA a very high density of the recently introduced North American spionid polychaete Marenzelleria viridis was present (Essink & Kleef 1993). M. viridis is a selective depositfeeder (Whitlatch 1980, Dauer et al 1981.…”