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Gulf corvina, Cynoscion othonopterus, is a vital component of commercial fisheries in the northern Gulf of California, but a lack of information on life history parameters have thus far prevented a comprehensive stock assessment. In this project, 530 specimens of Gulf corvina were collected from commercial gill net fisheries in the Colorado River Delta region in Sonora, Mexico, to characterize population structure, age and growth patterns, age and size at sexual maturity and batch fecundity. Fish ranged from 145 mm to 1013 mm in total length and from 1 to 8 years of age. Von Bertalanffy growth model parameters were: L∞ = 1006 mm, k = 0.255/yr, t0 = 0.616 years. Growth rates of Gulf corvina did not differ significantly between sexes, although females were predicted to reach a larger asymptotic length. Mean size (Lm50) and age (Am50) at sexual maturity from histological analyses of gonad tissues was 294.7 mm and 2.3 years for females and 267.5 mm and 2.0 years for males. Maturity estimates from otolith analyses did not differ between sexes and were similar to maturity estimates derived from gonadal histology, indicating that energy allocation shifts from growth to maturation and reproduction after year two. Batch fecundity ranged from 240,394 to 1,219,342 eggs with a mean of 684,293 eggs per spawn, and was correlated to both total length and gonad-free body weight. The distribution of oocyte diameters and oocyte stages indicate that Gulf corvina is a multiple batch spawner with asynchronous oocyte development and indeterminate annual fecundity.
Mass mortalities of intertidal purple sea urchins, Strongylocentrotus purpuratus occurred at Malibu Lagoon State Beach, California, in 2010 and 2011. Both events followed the first heavy rain of the season, and coincided with the illegal breaching of a coastal lagoon. Osmotic shock from low-salinity lagoon water, the likely cause of death, may have acted jointly with stress from subaerial exposure during especially low tides. Massive die-offs of purple sea urchins have occurred at other localities, usually after natural conditions created lethal levels of osmotic or thermal stress, or because of human efforts to harvest or to eradicate the species. Annually recurring lagoon ruptures at Malibu, combined with predation by western gulls, can have a profound impact on the local population of S. purpuratus and on intertidal ecology.
The purple amole Chlorogalum purpureum (Agavaceae) is a bulbous, perennial soap plant endemic to central California and listed as threatened under the U.S. Endangered Species Act since 2000. Chlorogalum p. purpureum occurs in the rain shadow of the Santa Lucia Range on Fort Hunter Liggett, south Monterey Co., and on Camp Roberts, north San Luis Obispo Co. Chlorogalum p. reductum occurs in the rain shadow of the La Panza Range in central San Luis Obispo Co., mostly on Los Padres National Forest and with potential for a substantially larger occupied area on private land. We review and enhance the existing knowledge of C. purpureum, in particular its life history and ecology, distribution, population sizes, threats, current management and conservation status. In 2012, invasive plants are the primary threat to C. purpureum.