Long-distance migration of South African deep-water rock lobster Palinurus gilchristi

Abstract

Long-term movement patterns of deep-water rock lobster Palinurus gilchristi were investigated off the south coast of South Africa using tag recapture data. Over a 12 yr period (1988 to 1999), 30 043 lobsters were tagged at 5 sites. From west to east, these were Cape Agulhas, West and East Agulhas Bank, Mossel Bay to Port Elizabeth, and Port Alfred. The overall recapture rate was 7.51%, with individuals remaining at large for up to 10.3 yr. Overall, 547 (25.8%) tagged lobsters of both sexes moved > 20 km within or between sites. We hypothesized that counter-current migration of juveniles would occur to redress downstream dispersal of phyllosoma larvae by the westerly flowing Agulhas Current. The vast majority of migrants (72.6%) did prove to be immature (carapace length < 72 mm) and did migrate eastwards against the prevailing flow of the Agulhas Current. The Cape Agulhas population (at the western extreme) comprised juveniles only. Over 97% migrated > 50 km, either southeastwards offshore to the West and East Agulhas Bank sites (106 lobsters, covering a mean distance of 154 km), or eastwards alongshore to the Mossel Bay to Port Elizabeth site near the center of the range (33 lobsters, 461 km). The fastest 5% of migrants moved at 0.43 to 0.78 km d -1

Mitochondrial DNA variation in spiny lobster Palinurus delagoae suggests genetically structured populations in the southwestern Indian Ocean

“…We suggest similar mechanisms retain a proportion of the P. delagoae larvae in eddies of the Mozambique Current, upstream of the southern KZN-1-4 population, thus giving rise to the shallow genetic partitioning between the 2 populations. P. gilchristi larvae off southern South Africa appear to be likewise retained inshore of the Agulhas Current, where downstream larval drift is redressed by return migrations of juveniles (Groeneveld & Branch 2002).…”

Modeling a Regime Shift in a Kelp Forest Ecosystem Caused by a Lobster Range Expansion

“…It is more likely that the increased abundance was due to an abrupt arrival of large rock lobsters-i.e., immigration of adults. Lobster migrations have been observed for a number of species (see, e.g., Annala andBycroft 1993, Pezzack andDuggan 1986), some of which can travel hundreds of kilometers (Moore andMcFarlane 1984, Groeneveld andBranch 2002). Most Jasus species undergo some form of inshoreoffshore migration associated with molting or reproduction (see review by Booth 1997); significant alongshore migrations are not common (Kelly 2001, Atkinson and Branch 2003, Barrett et al 2009), but in New Zealand, small proportions of populations of Jasus edwardsii (Hutton, 1875) do undergo large-scale migrations in response to changing environmental conditions (McKoy 1983, Annala andBycroft 1993), and mass alongshore migrations of Jasus verreauxi (H. Milne-Edwards, 1851) also take place (Booth 1997).…”

Review

“…Compensatory migrations by subadults from deep to shallower water, as well as alongshore against the prevailing current, to the adult breeding grounds have also been evolved in Palinurus gilchristi and P. delagoae (Groeneveld 2002;Groeneveld & Branch 2002). In Palinurus, short-term offshore-onshore homing movements also facilitate successful individual participation in reproduction, particularly in the processes of mating, incubation, and larval release (e.g., P. elephas, Hunter 1999 and P. delagoae Cockroft et al 1995;Groeneveld 2002).…”