DeMARTINI and FOUNTAIN: OVARIAN CYCLING FREQUENCY IN QUEENFISH 



space within the female's body cavity must set an 

 upper limit to the numbers of eggs of a given size 

 that can be simultaneously ripened and shed. 



Egg production in S. politus is not directly 

 proportional to weight, as it is in many marine 

 fishes (Bagenal 1967), but is instead an increasing 

 function of body weight (Figure 8). Relative fecun- 

 dity thus increases with body size in queenfish, as 

 is also the case for northern anchovy (Hunter and 

 Macewicz 1980) and two other offshore Pacific 

 species, jack mackerel and the gonostomatid Vin- 

 ciguerria lucetia (MacGregor 1976). 



Spawning Frequency and Annual Fecundity 



The 7-d ovarian cycling frequency of S. politus 

 is similar to that ofEngraulis mordax off southern 

 California, the only other species for which analo- 

 gous data now exists (Hunter and Goldberg 1980). 

 Having first determined the degeneration rate of 

 ovarian postovulatory follicles in laboratory fish. 

 Hunter and Goldberg (1980) used data on the 

 percent frequency occurrence of 1-d-old ovarian 

 follicles in field sample fish to estimate that E. 

 mordax spawns on average once every 6-8 d. 

 Estimates of average spawning interval (5.3 d) 

 based on relative incidence of northern anchovy 

 females bearing hydrated oocytes and new post- 

 ovulatory follicles were indistinguishable from 

 estimates based on frequency occurrence of day 

 1 postovulatory follicles (Hunter and Goldberg 

 1980). Spawning frequency is unrelated to female 

 body size in queenfish and the northern anchovy 

 (Hunter and Macewicz 1980). Incidence of hydra- 

 tion provides accurate estimates of spawning 

 frequency when, as with E. mordax and queen- 

 fish, an identifiable time of spawning exists, all 

 ripe eggs are shed at this time, and sample fish can 

 be collected accordingly. 



Annual egg production is largely dependent on 

 spawning frequency in multiple-spawning fishes. 

 The 6- to 8-d spawning interval of E. mordax 

 extrapolated over its 5-mo (January-May) peak 

 spawning season (Lasker and Smith 1977), indi- 

 cates that an individual northern anchovy ripens 

 and sheds about 20 batches of eggs per year 

 (Hunter and Macevvdcz 1980). At an average rela- 

 tive fecundity of 421 eggs/g (Hunter and Macewicz 

 1980), estimated annual egg production of the 

 northern anchovy is over 8,000 eggs/g, or about 14 

 times greater than previous estimates of annual 

 egg production inferred from standing crop fecun- 

 dities (606 eggs/g, MacGregor 1968; 556 eggs/g. 



Norberg''). Similarly, our estimates of the annual 

 egg production of S. politus range from 12 to 

 24 times the batch fecundity of recruit spawners 

 (90-d season) and of the largest repeat spawners 

 (180-d season), respectively. These data on the 

 ovarian cycling frequencies of the queenfish and 

 the northern anchovy indicate that prior studies 

 of egg production in multiple-spawning marine 

 fishes have in general underestimated annual egg 

 production by at least an order of magnitude. This 

 seems generally true whether the egg production 

 estimate was based on standing crop fecundity 

 (e.g., Simpson 1951; MacGregor 1957) or standing 

 crop fecundity multiplied by the number of spawn- 

 ings as inferred from the number of size classes of 

 yolked eggs (e.g., Hickling and Rutenberg 1936; 

 DeSilva 1973; but see Shackley and King 1977). 

 Our queenfish data and Hunter and Goldberg's 

 (1980) data for the northern anchovy illustrate 

 that the spawning frequency (hence annual egg 

 production) of serial-spawning fishes cannot usu- 

 ally be inferred from the number of size-frequency 

 modes of ovarian eggs. It follows that many past 

 estimates of the standing stocks of serial spawmers 

 that have inferred female abundance based on 

 egg-larval abundances and female fecundities 

 have greatly overestimated stock sizes. 



Production Cycles, Timing of Reproduction, 

 and Egg Size 



The seasonality of phyto- and zooplankton pro- 

 duction strongly influences the timing of repro- 

 duction of temperate marine fishes; in general 

 spawning seasons in the temperate zone are timed 

 so that planktonic offspring are exposed to peak 

 food densities (Gushing 1975). The spavming sea- 

 son of the northern anchovy, a species with many 

 reproductive attributes similar to those of queen- 

 fish, coincides with phytoplankton production at 

 the start of the production cycle, yet precedes the 

 disruption of prey patches that occurs due to 

 subsequent upwelling (Lasker 1975, 1978). Queen- 

 fish larvae prey on copepodites and adult zoo- 

 plankters (Barnett et a\}°), and thus it would 



''Norberg, R. H. 1975. Investigations on the fecundity 

 of northern anchovy, jack mackerel, and Pacific mackerel. 

 Unpubl. manuscr., 23 p. Calif. Dep. Fish Game, 350 Golden 

 Shore. Long Beach, CA 90802. 



'"Barnett. A. M., P. D. Sertic, and R. Davis. 1980. Data 

 summary of larval fish stomach analysis. A study submitted 

 to the Marine Review Committee of the California Coastal 

 Commission. September 7, 1980. Unpubl. rep., 22 p. Marine 

 Ecological Consultants of Southern California, 533 Stevens 

 Avenue, Suite D-57, Solana Beach, CA 92075. 



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