<abstract xmlns="http://www.w3.org/1999/xhtml">

<p><italic>Mytilopsis leucophaeata</italic> (Conrad, 1831) is native to the western Atlantic coast of North America. It has been reported in many regions outside its home range, including the Gulf of Gdańsk (the southern Baltic Sea). Although the conditions in the area seem to be favorable for the species, there have been no reports about its presence elsewhere in the gulf. However, the data probably did not reflect its actual distribution in the region, as the species can be easily misidentified for other bivalves living in the area, and it prefers hard substrates, which have not been studied as extensively as soft substrates. Our study was aimed at determining the actual distribution of <italic>M. leucophaeata</italic> in the Gulf of Gdańsk, the Vistula Delta and the Vistula Lagoon. The results showed that the species was not widely distributed in the Gulf of Gdańsk and was absent in the Vistula Lagoon. The only new records come from the Vistula Delta where the abundance of <italic>M. leucophaeata</italic> was up to 69 ind. m<sup>-2</sup>, i.e. significantly higher than in the Gulf of Gdańsk. Individuals found in the Vistula Delta were also significantly larger, with the length of shells reaching 22-23 mm, which is considered to be the maximum for the species.</p>
</abstract>

Mytilopsis leucophaeata (Conrad, 1831) is native to the western Atlantic coast of North America. It has been reported in many regions outside its home range, including the Gulf of Gdańsk (the southern Baltic Sea). Although the conditions in the area seem to be favorable for the species, there have been no reports about its presence elsewhere in the gulf. However, the data probably did not reflect its actual distribution in the region, as the species can be easily misidentified for other bivalves living in the area, and it prefers hard substrates, which have not been studied as extensively as soft substrates. Our study was aimed at determining the actual distribution of M. leucophaeata in the Gulf of Gdańsk, the Vistula Delta and the Vistula Lagoon. The results showed that the species was not widely distributed in the Gulf of Gdańsk and was absent in the Vistula Lagoon. The only new records come from the Vistula Delta where the abundance of M. leucophaeata was up to 69 ind. m-2, i.e. significantly higher than in the Gulf of Gdańsk. Individuals found in the Vistula Delta were also significantly larger, with the length of shells reaching 22-23 mm, which is considered to be the maximum for the species.

New records of Conrad’s false mussel <italic>Mytilopsis leucophaeata</italic> (Conrad, 1831) in the Vistula Delta

Department of Experimental Ecology of Marine Organisms, Institute of Oceanography

Oceanological and Hydrobiological Studies

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

New records of Conrad’s false mussel  (Conrad, 1831) in the Vistula Delta

Mytilopsis leucophaeata (Conrad, 1831) is native to the western Atlantic coast of North America. It has been reported in many regions outside its home range,...

Mytilopsis leucophaeata
Site		Abundance (ind. m )	Shell length (mm)	Temperature (°C)	Salinity (PSU)	Depth (m)	Substrate description	Dominant accompanying species
Gulf of Gdańsk	Torpedo testing facility (4)	19	5-13	14	6.9	7.5	Rough, concrete walls	Amphibalanus improvisusMytilus edulis trossulusGonothyraea loveni
Gulf of Gdańsk	Other 6 sites (1-3, 5-7)	0	-	5-18	6.8-7.2	5-20	Rough, concrete walls, steel shipwrecks, natural boulders	Amphibalanus improvisusMytilus edulis trossulusHydrozoa
Wisła Śmiała	National Sailing Center (8)	69	11-21	19	4.2	4	Very rough steel plating	Amphibalanus improvisusMytilus edulis trossulusRhithropanopeus harrisii
Martwa Wisła	“Galeon” shipyard (9)	31	13-22	19	6.4	4	Rough steel plating	Amphibalanus improvisusPoriferaRhithropanopeus harrisii
Martwa Wisła	Błotniki Yacht Port (12)	1 only one individual found during underwater observations	16	19	6.2	4	Smooth steel pile	Amphibalanus improvisusPorifera
Vistula	2 sites (10, 11)	0	-	18	0.4	2-3	Rough concrete pier and steel piles	Dreissena polymorphaGammarus spp.
Vistula Lagoon	5 sites (13-17)	0	-	17-19	2.5-4.0	2-3	Rough and smooth concrete pier	Dreissena polymorphaRhithropanopeus harrisii

New records of Conrad’s false mussel Mytilopsis leucophaeata (Conrad, 1831) in the Vistula Delta

Article Category: Short communication

Publicado en línea: 31 may 2017

Páginas: 231 - 236

Recibido: 15 ago 2016

Aceptado: 29 sept 2016

DOI: https://doi.org/10.1515/ohs-2017-0023

© Faculty of Oceanography and Geography, University of Gdańsk, Poland. All rights reserved.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Figure 1

Information about Mytilopsis leucophaeata and parameters measured at the study sites. Numbers in brackets presented in the “site” column refer to the numbers of sites used in Figure 1