Lyrodus pedicellatus (Quatrefages, 1849), commonly known as blacktip shipworm is a worm-like bivalve from the family Teredinidae which are wood-boring bivalves (Distel et al., 2002). Adult L.pedicellatus may range in size from a few millimetres to more than 2 m in length and up to several centimeters in diameter (Distel et al., 2002). They are identified as having non-segmented pallets, composed of single piece; the distal half of blade composed of periostracal cap varying in colour from light to dark brown and almost black, the cap envelopes the upper portion of a calcareous base. The calcareous portion of blade is distally conical, the periostracal cap more or less straight sided, with distal margin U-shaped, extending as lateral horns (Borges et al., 2012).

Lyrodus pedicellatus has been recorded from a number of locations around the world. These include the Atlantic Ocean, Mediterranean and Black Seas, Indian Ocean, and West Pacific, where it is mostly regarded as being cryptogenic. It is known to have been introduced to other areas, including South Africa, Hawaii, North America and New Zealand (Fofonnoff et al., 2003).

In South Africa it has only been recorded from Simon's Town, on the southwest coast (Peters, 2013), where it was first collected and re-described as Teredo robsoni by Moll and Roch (1931) cited by Mead et al., 2011.

Because they are wood borers, Lyrodus pedicellatus may be transported in ship hull, or ballast waters. This species also has a very brief planktonic larval stage during which they may be transported by currents.

Shipworms burrow in wood for both food and shelter (Waterbury et al., 1983; Distel et al., 2002; Fofonnoff et al., 2003). Lyrodus pedicellatus is the only marine invertebrate shown to grow and reproduce on a diet composed solely of wood, without filter feeding supplementation (Luyten et al., 2006). Shipworms have dense populations of intracellular endosymbiotic gram-negative bacteria within their gills, which provide enzymes that allow them to substantiate solely on wood. The enzymes critical for wood digestion and nitrogen supplementation found in this species include cellulase and nitrogenase (Waterbury et al., 1983; Luyten et al., 2006).

Shipworms are protandric hermaphrodites with internal fertilisation (Fofonnoff et al., 2003; Appelqvist 2015). They start off as male and later transform to female, however, they cannot self-fertilize. Prior to fertilisation, male teredinids release sperm into the water column. When the female eggs come to contact with the sperm, fertilisation occurs. Fertilized eggs are brooded in the gills to reach the veliger stage (Fofonoff et al. 2003). Lyrodus pedicellatus releases its larvae as pediveligers (an advanced stage of the veliger), which spends only 2 to 24 hours in the plankton (Turner and Johnson 1971 cited by Fofonnoff et al., 2003). The pediveliger larvae settle, rapidly metamorphoses and begin boring into wood within 2-3 days.

Planktonic