CAPRELLIDAE, Leach, 1814

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 : 2488-2489

Family CAPRELLIDAE

Caprella equilibra Say, 1818 Cryptogenic

This amphipod clings tightly to hydroids, algae and other typical fouling species, leading to easy transportation by shipping. We therefore consider ship fouling and ballast water as the most probable vectors. The origin of Caprella equilibra is unknown. It is now globally distributed ( McCain 1968) and common in South Africa from Namibia (west coast) to Mozambique (east coast), where it frequently forms part of the diet of reef fish. It was first recorded in South Africa “from screw of HMS Challenger, off Cape of Good Hope” by Stebbing (1888) and was established on the shore in False Bay by 1889 ( Stebbing 1910).

Caprella penantis Leach, 1814 Cryptogenic

Caprella penantis can be distinguished from Caprella equilibra by a distinct rostral tooth on the head. It also clings to various algae, sponges, hydroids, alcyonarians, zoantharians and bryozoans ( McCain 1968). The origin remains unknown: as with Caprella equilibra it is now widely distributed and is found in Hawaii, Japan, Australia, New Zealand and on both coasts of the United States, where it was one of the most common caprellids ( McCain 1968) before the arrival of Caprella muticum (Carlton unpublished findings), a species we expect to arrive soon in South Africa (if it is not already here). It was first reported in South Africa by Mayer (1903) from material collected in 1888 and is most likely transported through ship fouling and ballast water. In South Africa, it is distributed from Namibia (west coast) to KwaZulu-Natal (east coast).

Paracaprella pusilla Mayer, 1890 Cryptogenic

The male of this species is easily identified by the large triangular projection on the front of pereonite 2. The origin of Paracaprella pusilla is unknown. Its global distribution includes the Caribbean, the Atlantic coast of the United States, Tropical West Africa, East Africa, China and Hawaii. It has the same habitat as the other caprellids. As the first South African record is by Barnard (1955), who recorded it from Durban Harbour on the east coast, scraped from a ship’s hull, we regard ship fouling and ballast water are the most probable vectors.