SPHAEROMATIDAE, Latreille, 1825

Mead, A., Carlton, J. T., Griffiths, C. L. & Rius, M., 2011, Introduced and cryptogenic marine and estuarine species of South Africa, Journal of Natural History 45 (39 - 40), pp. 2463-2524 : 2481-2482

Family SPHAEROMATIDAE

Dynamene bidentata (Adams, 1800) Introduced

Dynamene bidentata is easily recognized by the large paired horn-like projections extending backwards from the posterior margin of pereon segment six and the enlarged, outward-pointing uropods. The first South African record of this rocky infaunal isopod is from 2006 by the authors in Port Elizabeth harbour on the southeast coast. Maggiore and Fresi (2008) record it as native to the Atlantic coast of Europe and as possibly introduced in the Mediterranean. We consider ship fouling and ballast water as the vectors.

Sphaeroma serratum (Fabricius, 1787) Introduced

This intertidal isopod is especially common on mangroves and is native to Europe. It was subsequently introduced to Australia, the southeast coast of Africa and Argentina ( Kittlein 1991) and first recorded from Durban Bay on the east coast of South Africa in 1950 ( Barnard 1951; Day and Morgans 1956). We consider ship fouling and ballast water to be the vectors.

Sphaeroma annandalei Stebbing, 1911 Cryptogenic

This intertidal isopod is found in estuarine systems where it bores into waterlogged mangrove wood. It was first described from and appears to be at least native to the Indian subcontinent ( Pillai 1961); it also occurs in the Persian Gulf, where it was redescribed as S. irakiensis Ahmed, 1971 ( Harrison and Holdich 1984), and it has been introduced to Brazil (Loyola and Silva 1960). We consider Sphaeroma annandalei as a possible introduction to KwaZulu-Natal on the east coast of South Africa. It was first recorded in 1926 at the mouth of the Mtunzini River. The most likely mode of introduction is ship fouling and ballast water; it remains cryptogenic, however, as infested floating mangrove wood may also be a vector.

Sphaeroma terebrans Bate, 1866 Cryptogenic

Sphaeroma terebrans is an estuarine wood-borer associated mainly with aerial roots of mangroves. It is thought to originate from the northern Indian Ocean, but is now widely distributed in warm and tropical waters including Australia, Sri Lanka, East Africa, Costa Rica, Brazil and the eastern and Gulf regions of the United States. The first South African record is from Barnard (1940). Its South African distribution ranges from Knysna Estuary on the southeast coast to Mtunzini River on the east coast. Ship fouling and ballast water are the likely vectors, although infected mangrove wood may also be a possible vector.

Sphaeroma walkeri Stebbing, 1905 Introduced

This fully marine species is found in estuaries to 5 m depths and is associated with fouling communities, as a result it is now one of the most widely distributed shiptransported isopods in the world. Its origins lie in the northern Indian Ocean ( Carlton and Iverson 1981), from where it was subsequently introduced to California, Florida, East Africa, Hong Kong and Spain, to name but a few regions. It was first collected in South Africa in 1915 and in 1917 in 9 m of water in Durban ( Barnard 1920), and by Stebbing (1917), without specified collection date, from Durban Bay on posts with ascidians. Ship fouling and ballast water are, without a doubt, the most likely vectors.

Paracerceis sculpta (Holmes, 1904) Introduced

This is an intertidal sphaeromatid isopod easily identified by its granular pleon, three prominent longitudinal ridges on the pleotelson and greatly extended, pointed exopod (of the uropod). It is found in shallow water on rocky shores. The first South African record is from Port Elizabeth harbour on the southeast coast in Barnard (1940). It originates from the Pacific coast of North America, but has also been recorded from Hawaii, Hong Kong, Australia, Brazil and the Mediterranean ( Espinosa-Perez and Hendrickx 2002). We consider it a ship fouling and ballast water introduction.