Habitat characters of Tigriopus californicus (Copepoda: Harpacticoida), with notes on the dispersal of supralittoral fauna

Abstract

Supralittoral splashpools representing 312,000 m2 of shoreline in Barkley Sound, British Columbia, were surveyed seasonally for tidal elevation, size, water properties, macroflora and faunal constituents coincident with colonization by Tigriopus californicus (Arthropoda: Copepoda). Overall, 90.1% of pools containing T. californicus were found between 3.0 and 5.0 m above lowest normal tide, with an average surface area-to-volume ratio of 7.06. Copepod populations were found at water temperatures of 6–33°C; salinity of <1–139 psu; pH of 6.1–9.5; and of 1.1–13.7 mg l−1 oxygen. Sediment and vegetation was sparse in T. californicus pools (mean cover 15.79±10.6% in 9.4±11.1% of pools, all species), and consisted most commonly of Enteromorpha compressa and Scytosiphon lomentaria and its Ralfsia-like alternate phase. Common fauna included mites, amphipods, littorines, and nematodes, with the highest diversity of co-inhabitants occurring in spring. Factors such as wind, wave action, and incidental fauna are discussed as potential agents of dispersal for splashpool copepods.

Metapopulation dynamics of Tigriopus brevicornis (Harpacticoida) in intertidal rock pools

“…A similar situation has been reported for San Juan Island, Washington, by Dethier (1980): T. californicus was almost always present in pools between the heights of mean and maximum high water. Powlik (1998bPowlik ( , 1999) also found T. californicus to be characteristic of pools just above the level of average high water, although he recorded higher extinction levels. Dybdahl (1994) reported high extinction levels in pools (approx.…”

“…Tigriopus spp. are conspicuous occupants of pools at and above the high water mark (Fraser 1936a,b, Igarashi 1959, Dethier 1980, Powlik 1999. Differences in life history tend to be slight (Fraser 1936a).…”

“…appear frequently in the literature, field surveys of populations are relatively rare (Powlik 1999). Such surveys generally summarise data on average population sizes by season and pool height on shore with little attention paid to more detailed spatial and temporal patterns of population dynamics.…”

Habitat characteristics and metapopulation dynamics of the copepod Tigriopus californicus

“…Most pools also received freshwater inflow from seasonal seeps of groundwater from adjacent cliffs. In addition to spatial variation in salinity, high evaporation rates result in strongly varying salinity levels in these rock pools over short timescales (Powlik 1999). Furthermore, these high intertidal pools are subject to long periods of tidal emersion, experiencing a broad range of diurnal and seasonal variation in temperature (Powlik 1999, Kelly et al 2012).…”

“…Copepods of the genus Tigriopus are generally restricted to high intertidal and supralittoral rock pools worldwide. These habitats are naturally fragmented with low connectivity among populations, making it an excellent model system to study metapopulation dynamics (Vittor 1971, Dybdahl 1994, Burton 1997, Powlik 1999, Johnson 2001. Desiccation of the habitat causes local extinction, as T. californicus does not have droughtresistant resting stages (Vittor 1971).…”