Hydractinia echinata ( Fleming, 1828 )

Calder, Dale R., 2012, On a collection of hydroids (Cnidaria, Hydrozoa, Hydroidolina) from the west coast of Sweden, with a checklist of species from the region 3171, Zootaxa 3171 (1), pp. 1-77 : 10-11

Hydractinia echinata ( Fleming, 1828)

Fig. 7

Alcyonium echinatum Fleming, 1828: 517 .

Hydractinia echinata .— Segerstedt, 1889: 7, 23.— Lönnberg, 1898: 51; 1903: 60.— Jäderholm, 1909: 48, pl. 2, figs. 6–9.— Kramp, 1935b: 74.— Rees & Rowe, 1969: 8.— Jägerskiöld, 1971: 62.

not Hydractinia echinata .— Lovén, 1858: 305, pl. 4, figs. 1–15 [= Podocoryna carnea M. Sars, 1846 ].

Type locality. British Isles, but without specific location data ( Fleming 1828: 517–518).

Museum material. Kosterhavet, 58°53.030’N, 11°05.567’E, 100–140 m, 10.ix.2010, biological dredge, R / V Nereus , one colony, on gastropod shell occupied by pagurid crab, with gonophores and spiral zooids, ROMIZ B3920 .

Remarks. A well-known species in northwestern Europe, Hydractinia echinata ( Fleming, 1828) is common on gastropod shells inhabited by pagurid crabs. A recent review of the species is given by Schuchert (2008a).

Hydractinia echinata is widespread and abundant in southwestern Scandinavia ( Kramp 1935b; Jägerskiöld 1971; Christiansen 1972).

Reported distribution. West coast of Sweden.—From the Svinesund at the Norway border ( Jägerskiöld 1971) to the Öresund ( Lönnberg 1898).

Elsewhere.—Mistakenly recorded over a wide geographic area, including the Mediterranean Sea and eastern North America. Its primary distribution appears to be in shallow boreal waters of northwest Europe ( Schuchert 2008a).

FIGURE 8. Podocoryna carnea : part of colony with two small gastrozooids and a spine, ROMIZ B3935. Scale equals 0.5 mm.

Figures

FIGURE 7. Hydractinia echinata: part of colony with spiral zooid, gonozooid, spine, and gastrozooid (left to right), ROMIZ B3920. Scale equals 0.5 mm.