D = depth of sample (m) 

 100 = number of square meters of surface 

 area. 



For example, a tow which strains 60 m 3 of water 

 through a depth of 12 m provides a SHF of 20. Mul- 

 tiplying the number of larvae in the catch by the SHF 

 gives an estimate of the number of larvae in the entire 

 water column under a surface area of 100 m 2 . Thus 

 the calculated number is dependent on both density 

 (number per m 3 ) and depth. 



Results 



We compared mean standard lengths and larval 

 abundance for each species by month, station, and 

 year to show spawning time and movement. 



Spot, 1972-73 Season 



Limited spawning may have occurred in Septem- 

 ber, since only one spot larva was caught in October, 

 when sampling began (Table 2). A few larvae were 

 caught at three offshore and two inshore stations in 

 November and at all offshore and four inshore 

 stations in December. Preflexion larvae (2.0-4.0 mm), 

 which denote recent spawning and were present at all 

 of those stations, increased markedly in abundance 

 in December, especially at offshore stations. 

 Mean length of larvae increased from November to 

 December by about 1 mm at offshore stations, but 

 decreased by slightly <1 mm at inshore stations. No 

 larvae were captured at estuarine stations until 

 January. In January, larvae were caught at all 



offshore, five inshore, and three estuarine stations. 

 Preflexion larvae were caught at two offshore 

 stations, but none were caught at inshore stations. 

 This was the last month that preflexion larvae were 

 present, indicating that spawning had ceased or at 

 least diminished. Mean lengths were 7.9 mm at 

 offshore and 9.2 mm at inshore stations, an increase 

 over December of 4.4 and 5.8 mm, respectively. This 

 was the largest increase recorded and reflects the 

 decline of preflexion larvae at offshore stations and 

 their absence at inshore stations. Mean length of lar- 

 vae caught at estuarine stations was 13.3 mm. In Feb- 

 ruary, as in the previous 2 mo, larvae were caught in 

 relatively large numbers at all offshore stations, but 

 in relatively low numbers at inshore stations. The 

 number of larvae in the estuary during February in- 

 creased fivefold over those caught in January. Larval 

 mean lengths had increased only slightly in each area 

 (offshore, inshore, and estuarine). In March, larvae 

 were caught at one offshore, seven inshore, and three 

 estuarine stations. Fewer larvae were caught in 

 March than in February, but mean lengths had in- 

 creased in each area. 



From October through March, an average of 28.2 

 and 2.2 spot larvae/station sampled were caught 

 offshore and inshore, respectively. Number of larvae 

 per station peaked at offshore (81.7) and inshore 

 (4.3) stations in December and at estuarine stations 

 (367.0) in February. Mean lengths of larvae from 

 offshore to inshore increased in November (no larvae 

 were caught in the estuary) and progressively in- 

 creased from offshore to the estuary during January- 

 March. The large number and relatively small size of 

 larvae caught offshore, as compared with the number 



407 



