To date there has been only on major study concerned with parasites of freshwater fishes of California. E. C. Haderlie (1953) summarized investigations up to that year and conducted a general survey of the monogenetic and digenetic trematodes, cestodes, nematodes, acanthocephalans, copepods, and hirudinians of fishes of Northern California. From 2010 fishes representing 36 species of 11 families examined over a three-year period, he obtained a total of 59 species of helminth parasites, copepods, and hirudinians, which include 20 species of digenea and 16 species of cestodes. In addition to the taxonomic study, Haderlie attempted to correlate the relative occurrence of the parasites with various ecological habitats. These data are incomplete, except for a general ecological discussion of the parasites taken from Clear Lake and its contributing streams. In the Sacramento-San Joaquin area the monogenetic trematodes are the only group that has been extensively studied. This work has been done by Dr. J. D. Mizelle of Sacramento State College. The primary purpose of the current investigation is to gain some knowledge of the species of endoparasites of fishes of the San Joaquin Delta. Two hundred and thirty sic fish were examined, including diadromous, potamodramous, anandromous, and territorial species of San Joaquin Delta. This has resulted in the recovery of two previously described and one new adult digenea, three metacercariae, two adult and three larval cestodes,and two cestodarians. Not included in this study are the Acanthocephala and Nematoda. A few cestodes are also not included because of their poor condition. The Host-Parasite List (p. 49) of this paper gives a summary of the fishes examined by Haderlie (H) and the present author (E) with the number of each species examined and the species of trematodes and cestodes recovered.

Studies on the helminth parasites of salamanders from California have been very limited. Between September 1975 and April 1977, 340 salamander belonging to seven species, Aneides flavipunctatus (7), A. lugubris (7), Batrachoceps attenuatus attenuatus (250), Ensatina eschscholtzii eschscholtzii (52), E. e. sierrae (17), Taricha torosa (6), and Dicamptodon ensatus (1), were examined for helminths and found to harbor 10 species, four of which are new. The parasites found are: Cestoda: Distoichometra ensatinae sp. nov. from Ensatina e. eschscholtzii and E. e. sierrae; and Baerietta diana (Helfer, 1948) Douglas, 1958 from Batrachoceps a. attenuatus. Nematoda: Dibulbiger caballeroi sp. nov. from Dicamptodon ensatus; Pseudaplectana cable isp. nov. from Ensatina e. eschscholtzii, Aneides flavipunctatus, and A. lugubris; Psudaplectana waltoni sp. nov. from Batrachoceps a. attenuatus; Cosmocercoides dukae (Holl, 1928) Travassos, 1931 form, Taricha torosa; Rhabdias sp. from Taricha torosa; Thelandros salamandrae (Lehmann, 1954) Schad, 1960 from Ensatina e. eschscholtzii, Aneides flavipunctatus and A. lugubris; T. magnavulvaris (Rankin, 1937) Schad, 1963 from Taricha torosa; and T. minutus Read and Amreim, 1952 from Batrachoceps a. attenuatus. A new host record is established for Thelandros salamandrae from Ensatina e. sierrae. A host-parasite list covering work in California, Oregon, and British Columbia is also included.