times in other California flatfishes are variable 

 with a tendency toward winter. Fitch and Laven- 

 berg (1971) reported the following spawning 

 periods: Platichthys stellatus, November-Febru- 

 ary; Microstomus pacificus, November-March; 

 Citharichthys sordidus, July-September; Para- 

 lichthys californicus, February-July. Goldberg 

 (1981) reported summer spawning in Symphurus 

 atricauda and summer-fall spawning (Goldberg 

 1982) in Hippoglossina stomata. Spawning in 

 Citharichthys stigmaeus occurs April- September 

 (Ford 1965). Pleuronichthys verticalis which was 

 investigated by Fitch (1963) and Goldberg (1982) 

 and Glyptocephalus zachirus which Frey (1971) 

 reported on were in spawning condition through- 

 out the year. Such year-round spawning is un- 

 common among California flatfishes. 



Acknowledgments 



I am grateful to M. Heinz and T. Pesich (Or- 

 ange County Sanitation District, Marine Labora- 

 tory) and R. Sewell (Orange County Board of 

 Education, Marine Studies Institute) for assist- 

 ance in obtaining specimens. This study was 

 aided by a Whittier College faculty research 

 grant. 



Literature Cited 



Fitch, J. E. 



1963. A review of the fishes of the genus Pleuronichthys. 

 Los Ang. Cty. Mus. Contrib. Sci. 76:1-33. 

 Fitch, J. E., and R. J. Lavenberg. 



1971. Marine food and game fishes of California. Univ. 

 Calif. Press, Berkeley, 179 p. 



Ford, R. E. 



1965. Distribution, population dynamics and behavior of 

 a bothid flatfish, Citharichthys stigmaeus. Ph.D. The- 

 sis, Univ. Calif., San Diego, 243 p. 

 Frey, H. W. (editor). 



1971. California's living marine resources and their utili- 

 zation. Calif. Dep. Fish Game, 148 p. 



Goldberg, S. R. 



1981. Seasonal spawning cycle of the California tongue- 

 fish, Symphurus atricauda (Cynoglossidae). Copeia 

 1981:472-473. 



1982. Seasonal spawning cycles of two California flat- 

 fishes, Pleuronichthys verticalis (Pleuronectidae) and 

 Hippoglossina stomata (Bothidae). Bull. Mar. Sci. 32: 

 347-350. 



Hunter, J. R, and S. R. Goldberg. 



1980. Spawning incidence and batch fecundity in north- 

 ern anchovy, Engraulis mordax. Fish. Bull., U.S. 77: 

 641-652. 

 Miller, D. J., and R. N. Lea. 



1976. Guide to the coastal marine fishes of California. 



Calif. Dep. Fish Game, Fish Bull. 157, 249 p. (Rev. 

 publ. by Div. Agric. Sci., Univ. Calif., Richmond). 



Stephen R. Goldberg 



Department of Biology 

 Whittier College 

 Wfiittier. CA 90608 



OTTER TRAWL SAMPLING BIAS OF THE 



GILL PARASITE, URONECA VULGARIS 



(ISOPODA, CYMOTHOIDAE), 



FROM SANDDAB HOSTS, 



CITHARICHTHYS SPP. 



Lironeca vulgaris (Crustacea, Isopoda, Cymo- 

 thoidae) is a common parasite infesting the gill 

 chambers of many marine fish species from the 

 California coast. Both male and female isopods 

 reside in the gill chambers of sanddab hosts. 

 Aspects of the ecology of this parasite and host 

 specificity are given in Brusca (1978, 1981) 

 and Keusink (1979). Both authors discuss the 

 propensity of isopods, particularly males, to 

 abandon hosts in otter trawls, which may cause 

 false host records. Further, if host abandonment 

 occurs during the trawling operation then esti- 

 mates of prevalence (no. of infested hosts/total 

 no. of hosts), relative parasite density (total no. of 

 parasites/total no. of hosts), and mean parasite 

 intensity (total no. of parasites/no. of infested 

 hosts) will be biased. During a study of the inter- 

 actions between L. vulgaris and two sanddab 

 hosts, Citharichthys stigmaeus and C. sordidus, I 

 analyzed the efficiency of traditional otter trawl 

 collecting methods. Prevalence, relative parasite 

 density, and mean parasite intensity were com- 

 pared for samples of a host population gathered 

 by otter trawls and divers utilizing scuba. 



Methods 



Speckled sanddabs, Citharichthys stigmaeus, 

 and Pacific sanddabs, C. sordidus, were collected 

 from a site about 0.5 km west of Goleta Point, 

 Santa Barbara County, Calif., just seaward of an 

 extensive bed of giant kelp, Macrocystis pyrifera. 

 The depth was 16 m and the substrate consisted 

 of fine sands and silts with occasional stands of 

 the brown alga, Pterygophora California, and 

 patches of eelgrass, Zostera marina. 



FISHERY BULLETIN: VOL. 80, NO. 4. 1982. 



907 



