Goose Barnacle Lepas anatifera on lost trawl netting in the southern North Sea

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GOOSE BARNACLE LEPAS ANATIFERA ON LOST TRAWL NETTING IN THE SOUTHERN NORTH SEA JIM ELLIS The goose barnacle Lepas anatifera Linnaeus 1758 (Subclass Cirripedia; Superorder Thoracia; Order Pedunculata; Suborder Lepadomorpha; Family Lepadidae) is widespread in tropical to warm temperate oceans and seas. This stalked barnacle is commonly found attached to floating and drifting objects, whether natural (e.g. logs and seaweed) or anthropogenic ‘flotsam and jetsam’ (Minchin, 1996; Kiessling et al., 2015). Whilst recorded quite frequently from the western and southern coasts of the British Isles (Hayward & Ryland, 1990; Davoult et al., 1993; Minchin, 1996; Herbert & Muxagata, 2009), there are fewer records of lepadid barnacles in the North Sea (Boëtius, 1952; Sneli, 1983).

The genus Lepas is distinguished from other genera of stalked barnacles in northern European seas by having a capitulum (the ‘head’ on top of the stalk) with five well-developed calcareous plates, comprising paired terga, paired scuta and a single carina, the latter structure not angled (c.f. the genus Dosima).

Four species of Lepas have been listed for the British Isles (Darwin, 1851; Hayward & Ryland, 1990; Southward, 2008). Of these, the plates on the capitulum of L. pectinata and L. anserifera have pronounced ridges and furrows, whilst the capitula plates of L. hilli and L. anatifera are either smooth or with fine striations. The two latter species can be distinguished on the basis of the distance between the carina and the scutum, which is narrow in L. anatifera and wider in L. hilli. Furthermore, the peduncle (stalk) of L. anatifera is an even coloured (dark brown), whilst the peduncle of L. hilli has a lighter orange-coloured collar near the base of the capitulum.

On 9 August 2016, a small section of discarded trawl netting was caught during an annual groundfish survey at a site ca. 75 km east-northeast of Lowestoft (52.81°N, 2.75°E; 39 m water depth; Figure 1). Four specimens of L. anatifera were attached to

Figure 1: Southern North Sea showing the site () where the specimens of Lepas anatifera were collected.

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Suffolk Natural History, Vol. 52

Figure 2: Specimen of Lepas anatifera showing the carina (C), tergum (T), scutum (S) and peduncle (P). the netting (Plate 16). The four specimens were 10.9, 13.9, 14.3 and 20.0 mm long (capitulum height, as measured from the margin of the scutum nearest the peduncle to the distal tip of the tergum). The terga and scuta were white and smooth with fine striations (Figure 2). There was orange colouration between the capitula plates, and the peduncle was a uniform dark brown. Interestingly, all specimens were attached to knots in the netting.

Whilst the records here cannot be used to confirm the presence of L. anatifera in Suffolk waters, the presence of these specimens further offshore in the southern North Sea is noteworthy, as is the colonisation of lost trawl netting as a vehicle for their dispersal.

References BoÍtius, J. (1952). Some notes on the relation to the substratum of Lepas anatifera L. and Lepas fascicularis E. et S. Oikos, 4: 112–117.

Darwin, C. (1851). A monograph on the sub-class Cirripedia with figures of all the species. Part 1: The Lepadidae or pedunculated cirripedes. The Ray Society, 400 pp. + 10 plates. Reprinted by the Johnson Reprint Corporation (1968).

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Davoult, D., Dewarumez, J. M. & Glacon, R. (1993). New additions to macrobenthic species from the French coasts of the eastern English Channel and North Sea. 4.

Miscellaneous groups. Cahiers de Biologie Marine, 34: 55–64.

Hayward, P. J. & Ryland, J. S. (Eds.) (1990). The marine fauna of the British Isles and north-west Europe, Volume 1: Introduction and Protozoans to Arthropods. Oxford University Press, 656 pp.

Herbert, R. J. & Muxagata, E. (2009). Barnacles (Crustacea: Cirripedia) of the Solent and Isle of Wight. Proceedings of the Isle of Wight Natural History and Archaeology Society, 24: 42–56.

Kiessling, T., Gutow, L. & Thiel, M. (2015). Marine litter as habitat and dispersal vector. In Marine anthropogenic litter (M. Bergmann, L. Gutow and M. Klages, Eds.). Springer International Publishing, 141–181.

Minchin, D. (1996). Tar pellets and plastics as attachment surfaces for lepadid cirripedes in the North Atlantic Ocean. Marine Pollution Bulletin, 32: 855–859.

Sneli, J. A. (1983). Larvae of Lepas anatifera L., 1758, in the North Sea (Cirripedia).

Crustaceana, 45: 306–308.

Southward, A. J. (2008). Barnacles: Keys and notes for the identification of British species. Synopses of the British Fauna (New Series) no. 57. Field Studies Council, 152 pp.

J. Ellis

Jim R. Ellis CEFAS, Pakefield Road, Lowestoft, Suffolk, NR33 0HT

Plate 16: Specimens of Lepas anatifera found on lost trawl netting (p. 4).

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