During the 1960s and 1990s, the California Department of Fish and Game tagged 8,634 barred sand bass in southern California, and 972 fish (11%) were recaptured. Tag returns suggest barred sand bass are transient aggregate spawners that form spawning aggregations consisting of both resident and migrant individuals. Spawning residency at a historic spawning location was estimated by the frequency of returns over time; most same-year returns (82%, n  =  141) were recaptured within a 7 to 35-day period. The maximum recapture distance was 92 km. The average (± SD) non-spawning season recapture distance from peak spawning season tagging locations was 13 ± 8 km, and movement was generally northward. A positive relationship existed between fish size (TL) and migration distance to non-spawning season recapture locations. Fish tagged at a presumed non-spawning season residence were primarily recaptured south of the tagging location during peak and late spawning season; the average migration distance was 17 ± 15 km. Recaptures in subsequent years showed a high degree of spawning (80%, n  =  135) and non-spawning (73%, n  =  11) site fidelity. This is the first documentation of the spawning-related movements of barred sand bass and will be important for informing management decisions regarding this popular sport fish.

The bean clam, Donax gouldii, is an intermediate host of the monorchid trematode Postmonorchis donacis. Bean clams were collected from nine locations in San Diego County, CA, and siphons and mantle edges examined. Two hypotheses were tested: (1) parasitism increases with valve length, and (2) female clams have more parasites than males. A positive relationship was found between clam length and parasitism at all locations; there was no significant difference (α  =  0.05) in male and female parasitism rates. Spatial variation on a kilometer scale was observed in trematode infestation rate and intensity.