FISHERY BULLETIN: VOL. 79, NO. 3 



tenuis (Clark 1925). A protracted spawning season 

 is generally characteristic of repeat spawners 

 (Nikolskii 1969). 



Temporal Patterns of Spawning 



The peaks in spawning synchrony among fe- 

 male S. politus during the moon's first quarter 

 are likely adaptive for several reasons. Spawning 

 at dusk while the night sky is still fairly dark 

 probably helps conceal adults and planktonic 

 eggs from visual predators. Furthermore, tidal 

 exchanges are minimal during the moon's first 

 quarter (Figure 2B) and the conservation of plank- 

 tonic eggs and larvae in nearshore areas may be 

 facilitated. Juvenile and adult queenfish inhabit 

 depths < 20 m during most of the year (DeMartini 

 and Larson^), and most queenfish larvae are 

 found in water <30 m within 4-5 km of shore 

 (Barnettetal.^). 



Little data exist on the subseasonal spawning 

 patterns of other temperate marine fishes. The 

 data of Clark (1934) suggested monthly spawming 

 peaks for Pacific sardine around times of the 

 full moon. Farris (1963) later showed that no 

 lunar spawning periodicity exists for Pacific sar- 

 dine and jack mackerel off southern California, 

 although diel and seasonal patterns occur in both 

 species. Northern anchovies spawn between 2200 

 and 0400 h (Smith 1978, cited in Hunter and 

 Goldberg 1980). A number of north Atlantic fishes 

 have diel spawning periodicities (Simpson 1971). 

 Lunar spawning intervals are known for several 

 littoral fishes that spavvn demersal eggs (e.g., 

 California grunion, Clark 1925; mummichog, 

 Fundulus heteroclitus , Taylor et al. 1979, Taylor 

 and DiMichele 1980). 



Sex Ratio of Spawning Fish 



Although the overall adult sex ratio of iS. politus 

 was only slightly male biased, the male:female sex 

 ratio averaged about 2:1 in groups offish in which 

 the highest proportion of ready-to-spawn females 



^E. E. DeMartini and R. J. Larson, Marine Science Institute, 

 Univ. Calif., Santa Barbara, CA 93106, unpubl. data. 



'Bamett, A. M„ A. E. Jahn, R D. Sertic, and W. Watson. 

 Long term average spatial patterns of ichthyoplankton off San 

 Onofre and their relationship to the position of the SONGS 

 cooling system. A study submitted to the Marine Review Com- 

 mittee of the California Coastal Commission, July 22, 1980. 

 Unpubl. rep., 32 p. Marine Ecological Consultants of Southern 

 California, 533 Stevens Avenue, Suite D-57, Solana Beach, 

 CA 92075. 



were present. Hunter and Goldberg (1980) noted 

 the same phenomenon in spawning schools of the 

 northern anchovy and other pelagic spawners. 

 The skewed sex ratio in spawning schools of the 

 queenfish, however, should not bias our estimates 

 of female spawning frequency either for or against 

 spawning females, as may be the case with north- 

 ern anchovy (Hunter and Goldberg 1980; Hunter 

 and Macewicz 1980), since queenfish were sampled 

 within the entire water column over the total day- 

 time onshore-offshore distribution of the species. 



Egg Production and Fish Body Size 



The batch fecundity of S. politus is proportional 

 to length cubed and is better correlated with 

 weight than with body length, both being general 

 phenomena in fishes (Nikolskii 1969). 



The low standing crop ovary weights ( 2-4% body 

 weight) of S. politus, and of multiple-spawning 

 fishes in general (e.g., 6% in the northern an- 

 chovy Smith and Lasker 1978; 4.1-9.0% in the 

 scaled sardine, Harengulajaguana, Martinez and 

 Houde 1975), greatly underrepresent total egg 

 production by serial spammers. We estimate that a 

 25 cm (253 g) S. politus with an annual egg 

 production of about 2.2 million eggs (24 batches 

 averaging 90,000 eggs, each egg an average 0.635 

 mm diameter and 0.134 mg fresh weight) expends 

 the equivalent of 114% of its body weight in eggs in 

 a year. This is not unexpectedly high, since, for 

 example, females of one species of silverside, 

 Menidia audens, produce about 6-8 times their 

 body weight in eggs per year (Hubbs 1976). This is, 

 however, considerably more than the seemingly 

 great egg investments made by fishes in which 

 females are single clutched and spawn large, 

 benthic, adhesive eggs (e.g., 20% in the fourhorn 

 sculpin, Myoxocephalus quadricornis, Westin 

 1968; 30% in the red Irish lord, Hemilepidotus 

 hemilepidotus , DeMartini and Patten 1979; 34% 

 in the plainfin midshipman, Porichthys notatus, 

 DeMartini^). Doubtless the poorer survival of 

 small, planktonic eggs and larvae (Ware 1975) 

 necessitates the production of greater numbers of 

 eggs. Partial overlap in the ripening of eggs in 

 successive batches allows greater numbers of eggs 

 of a given size to be produced per unit time, as 



DeMartini, E. E. Variations in fecundity and growth among 

 geographic populations of the plainfin midshipman, Porichthys 

 notatus. Manuscr. in prep. Marine Science Institute, Univ. 

 Calif., Santa Barbara, CA 93106. 



556 



