Tidepools as refuges: Predation and the limits of the harpacticoid copepod Tigriopus californicus (Baker)

POPULATION GENETICS OFTIGRIOPUS CALIFORNICUS. II. DIFFERENTIATION AMONG NEIGHBORING POPULATIONS

“…Laboratory experiments (Bozic, 1975) show that when presented with a choice, Tigriopus preferentially move to vessels that have been previously occupied by adult conspecifics. Dethier (1980) has pointed out that an "aggregation pheromone" suggested by Bozic's work might play an important role in the return of copepods to the high intertidal after they are washed out by severe wave action. This behavioral response, which amounts to a homing response, may have important population genetic implications.…”

“…Pools previously inhabited by Tigriopus were observed to be filled with sand in early 1979 and no copepods could be located. While this does not mean that extinction had, in fact, occurred, it indicates that population sizes were significantly reduced; the probability that Tigriopus could maintain large subtidal populations during such conditions is very low (see Vittor, 1971;Dethier, 1980). In light of these observations, we suggest that the lack of significant polymorphism at HMB and SCK (Table 1) might reflect regional population bottlenecks or extinction with subsequent loss of genetic variation due to genetic drift and/or founder effects during recolonization.…”

“…Two factors may account for these observations: (1) predation and (2) Tigriopus behavior. With respect to the former, Dethier (1980) has suggested that predators may be largely responsible for the restriction of Tigriopus to high intertidal pools. Tigriopus is attractive prey for many abundant intertidal species.…”

“…Because Tigriopus larvae and adults are frequently washed from their intertidal habitat (Vittor, 1971;Dethier, 1980;pers. observ.…”

Habitat characteristics and metapopulation dynamics of the copepod Tigriopus californicus

“…4A,C), and pools of intermediate ephemerality had the highest occupancy. A possible explanation for the low occupancy in more permanent (large) and saline pools is the high predation risk in these localities (Dethier 1980). Generally, these pools are positioned at lower shore height or are big enough to never dry up (Figs.…”