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Fishery Bulletin 88(2), 1990 



Table 2 



Reported commercial landings and estimates of the total 

 marine recreational landings of leopard sharks in northern 

 California, 1980-87. Recreational landings are Type A catches 

 (observed landings) for north of San Luis Obispo County to 

 the Oregon border, based on the Pacific Coast Marine Recrea- 

 tional Fishery Statistics Survey (provided by John F. Witzig, 

 Natl. Oceanic Atmos. Adm., Natl. Mar. Fish. Serv., Silver 

 Spring, MD 20910, 14 June 1989). Commercial landings are 

 summed for northern California ports. 



Northern California landings 



Year 



1980 

 1981 

 1982 

 1983 

 1984 

 1985 

 1986 

 1987 



tion of catch and effort by moderately small time or 

 area segments are unavailable for either the recrea- 

 tional or commercial fisheries. The smallest divisions 

 for the recreational fishery are northern and southern 

 California. For the commercial fishery, only the place 

 of landing and not the place of catch is recorded, and 

 effort data are nonexistent. 



Information on reproduction, stock replacement 

 rates, and stock interaction is scanty and mostly un- 

 documented. Estimates of length at maturity for males 

 have ranged from 70 to 119 cm and for females from 

 100 to 129 cm; size at birth is about 20 cm (Ackerman 

 1971, Compagno 1984, Rusher 1987). The gestation 



period is estimated at 10-12 months and parturition 

 takes place in spring, according to Ackerman (1971) 

 who worked with Elkhorn Slough fish in Monterey 

 County, California. Certain other observations cor- 

 roborate this. Moser and Sakanari* examined an ag- 

 gregate of pooled embryos from fish taken in the fall 

 in San Francisco Bay and the measurements formed 

 a unimodal distribution with little variation in embryo 

 sizes among litters, which is the expected pattern for 

 an annual reproductive cycle. More than one mode 

 among litters would be observed for a gestation period 

 of 2 or more years. In addition, R. Russo (East Bay 

 Park Dist., Alameda, CA 94169, pers. commun., 27 

 March 1984), sampling in South San Francisco Bay, has 

 noted a predominance of pregnant females with near- 

 term pups mainly from March through June (April- 

 May peak), indicating a once-a-year parturition in 

 spring. Pupping could be annual and occur in alternate 

 years, with a 'recuperative' year between, but then 

 about half of the mature female population would be 

 in a nonreproductive condition at any given time. Of 

 the 90 females over 120 cm that Ackerman (1971) ex- 

 amined from Elkhorn Slough, 94% had embryos or fer- 

 tilized eggs in at least one ovisac; and all females > 1 10 

 cm total length (TL) collected by Rusher (1987) in 

 Elkhorn Slough and Monterey Bay and San Francisco 

 Bay showed signs of either pregnancy, recent birth, or 

 embryo abortion. Therefore, we use the assumption of 

 an annual reproductive cycle in later sections dealing 

 with stock replacement by reproduction. The leopard 

 shark is primarily a benthic feeder (Russo 1975, Talent 



*Drs. M. Moser and J. Sakanari (Long Marine Lab.. Univ. Calif., 

 Santa Cruz, pers. commun., Sept. 1984) report that in a sample 

 of nine pregnant females taken on 10 September 1984, presumably 

 in midterm, the mean embryo length w;is 11.26 cm(1.51 SD), (« = 51 

 embryos). 



