Domestication Assessment

The domestication effects of fish held in captivity are often observed even after the first generation. The FCCL is conducting multiple studies on the effects of domestication on cultured Delta Smelt. One mechanism by which this is manifested is by artificial selection. Artificial selection, as opposed to natural selection, will tend to have a larger impact on fish held in captivity by favoring those individuals that have traits that increase their reproductive success (e.g. increased density, reduced predation, and competition). The FCCL has observed better survival from offspring coming from cultured-cultured crosses than offspring from wild-wild crosses. For the purpose of assessing cultured Delta Smelt’s ability to handle semi-natural conditions with little to no human care, several trials were conducted with larval, juvenile and adult stages of the fish. The need to evaluate the effects of domestication on our multi-generational cultured fish is critical, potential reintroduction and management of Delta Smelt depends on this understanding.

Related Publications:

LaCava M, Griffiths J, Ellison L, Carson E, Hung TC, Finger A (2023) Loss of plasticity in maturation timing after ten years of captive spawning in a delta smelt conservation hatchery, Evolutionary Applications 16(11), 1845-1857.

Ellison L, Rahman MM, Finger AJ, Sandford M, Hsueh CH, Schultz AA, Hung TC (2023) Size, fecundity, and condition factor changes in endangered delta smelt Hypomesus transpacificus over 10 generations in captivity, Aquaculture, Fish and Fisheries 3(4), 353-365.

Hung TC, Rosales M, Kurobe T, Stevenson T, Ellison L, Tigan G, Sandford M, Lam C, Schultz A, Teh S (2019) A pilot study of the performance of captive-reared delta smelt Hypomesus transpacificus in a semi-natural environment, Journal of Fish Biology 95(6), 1517-1522.

Finger AJ, Mahardja B, Fisch KM, Benjamin A, Lindberg J, Ellison L, Ghebremariam T, Hung TC, May B (2018) A managed conservation hatchery for delta smelt shows evidence of genetic adaptation to captivity after 9 generations, Journal of Heredity 109(6), 689-699.

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