It’s Sunday morning 6. may, 9 o’clock in the morning. A group of 7 people walk from the parking behind restaurant ‘de Zeester’ to the already dry mud banks of the Oosterschelde. Full of hope we defy the cold (8°C) on our way to our collecting spot. One thing catches the eye immediately, everywhere we look lie empty doublets of Venerupis philippinarum (Adams & Reeve, 1850). We were already informed in advance about this phenomenon by Frans de Jong, who was there a month ago (see: LINK). We don’t know the reason of the mass beaching of these shells but it was a good start of the day. Between the V. philippinarum we found a striking number of recent single valves of Glycymeris glycymeris (Linnaeus, 1758) a species with the Channel for it northernmost limit of its range. But there lives a small population in the Oyster wells of Yerseke. After collecting a sample of both exotic species, we walk further.
Then we come to the place with the species that Gorishoek is famous for. After turning some stones we found many living Urosalpinx cinerea (Say, 1822) and fewer but still large parties of Ocenebra inornata (Récluz, 1851). The nice yellow eggs are a sight for sore eyes and very fascinating. Between these two species of Muricidae are lots of living Littorina littorea (Linnaeus, 1758), Gibbula cineraria (Linnaeus, 1758) and Patella vulgata Linnaeus, 1758. Of all the five species I collect some. In the next month I try to prepare the radula of my collected P. Vulgata.
A little further we come to an area with Nucella lapillus (Linnaeus, 1758). This is the species of Muricidae which belongs to this place but it is slowly supplanted by exotic species of that family. But there is some hope. This species has laid eggs too, so we can enjoy the beauty of this animal for one more generation. We hope it will be more. I’ve also found an unusually big specimen of N. lapillus, which was around 50mm.
Another eyecatcher are the lots of empty shells of P. vulgata which are spread throughout the searched area. I’ve collected around 30 empty shells. That’s very different from the small samples of empty shells I’ve collected at Hoek van Holland and Borssele. Also there laid many single valves of Aequipecten opercularis (Linnaeus, 1758) and doublets of Ostrea edulis Linnaeus, 1758. So that is a indication that Crassostrea gigas (Thunberg, 1793) has not completely displaced O. edulis. But I don’t think it could be saved. Maybe they were the last Dutch doublets of the shell I’ll see in my life.
Some other interesting finds are a single valve of Arctica islandica (Linnaeus, 1767) and that, at the end of the Oosterschelde looks like a great specimen. A recent right valve of Pecten maximus (Linnaeus, 1758) with a size of 115mm is uncommon, which lives on higher depths in the Northsea. Shells of of adult animals beach infrequently.
After some two hours searching, we return to the cars. Over a cup of tea we talk about our finds and then we leave the sea and go back home. When I arrived home I inspectedt my shells. And found on the shells three Lepidochitona cinerea (Linnaeus, 1767). I’ve searched for that species there but I haven’t found it.
Later I will attach a full species list of this day.
- Bruyne, R.H. de (2004): Veldgids Schelpen. — KNNV Uitgeverij, 234 pp.
- Faasse, M.A. & Ligthart, A.H.M. (2007): The American oyster drill, Urosalpinx cinerea (Say, 1822), introduced to The Netherlands – increased risks after ban on TBT? — Aquatic Invasions 2(4): 402-406
- Faasse, M.A. & Ligthart, A.H.M. (2009): American (Urosalpinx cinerea) and Japanese oyster drill (Ocinebrellus inornatus) (Gastropoda: Muricidae) flourish near shellfish culture plots in The Netherlands. — Aquatic Invasions 4(2): 321-326