been described. DeCiechomski (1968) has discussed 

 occurrence and photographed eggs and yolk-sac 

 larvae of Brevoortia aurea from Argentina. 



Using our rearing techniques (Houde 1973b), it 

 was relatively simple to rear yellowfin menhaden 

 from eggs to advanced juveniles. Presumably the 

 other species, including Atlantic and Gulf 

 menhaden, can be reared by similar methods if 

 their eggs can be obtained. It should now be pos- 

 sible to conduct experiments under laboratory 

 conditions, testing environmental factors on 

 development of eggs and larvae of these impor- 

 tant commercial species. 



METHODS 

 Collecting Eggs 



Naturally fertilized eggs from Biscayne Bay, 

 Miami, Fla. were collected in 1-m diameter, 505- 

 /xm mesh plankton nets suspended from the dock 

 of the Rosenstiel School of Marine and At- 

 mospheric Science on 3 November and 26 

 November 1972. Surface temperatures were 25.4° 

 and 22.7°C on the respective collecting days and 

 salinity was 32-33°/ oa Yellowfin menhaden eggs 

 were sorted by pipette from the other plankton 

 organisms. The eggs that were sorted were known 

 to be yellowfin menhaden because some of the 

 same type had been hatched and the larvae reared 

 during rearing trials in 1971. A total of 90 eggs on 

 3 November and 170 eggs on 26 November were 

 placed in rectangular tanks of 38-liter capacity for 

 rearing. 



Rearing and Preserving Methods 



Rearing techniques were similar to those 

 described by Houde (1973b) and Houde and Palko 

 (1970). For the first 20 days of culture, temperature 

 was controlled at 26° ± 1.0°C. Salinities ranged 

 from 33.5 to 37.0°/ oo and light was provided by 

 fluorescent fixtures at an intensity of 2,500 Ix. 

 Zooplankton, consisting mostly of copepod nauplii 

 and copepodites, collected in a 35-/xm mesh plank- 

 ton net, was fed to larvae for the first 12 days; 

 subsequently Artemia salina nauplii were fed in 

 addition to zooplankton. A total of 8 embryos and 

 66 surviving larvae were preserved in 5% buffered 

 Formalin^ during the culture period to provide the 



'Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



series used to describe development. Specimens 

 from 3.7 mm to 36.2 mm SL (standard length) were 

 included in the developmental series (Table 1), but 

 many juveniles continued to survive and were 

 reared to lengths of 50-60 mm before experiments 

 were terminated. 



Meristics and Morphometries 



Methods for counting and measuring are iden- 

 tical to those used by Houde et al. (1974) for 

 Harengula jaguana Poey larvae. 



Fin rays were counted in each of the developing 

 fins of unstained larvae (Table 2). Myomeres were 

 counted (Table 3) and examined in relation to the 

 dorsal fin and anus. The following myomere counts 

 were made: 



Total myomeres: all myomeres; does not include 



the triangular area preceding the first 



myoseptum. 

 Preanus myomeres: number anterior to the 



anus. 

 Postanus myomeres: number posterior to the 



anus. 

 Predorsal myomeres: number anterior to the 



dorsal fin origin. 

 Postdorsal-preanus myomeres: number between 



the posterior insertion of the dorsal fin and the 



anus. 



The following measurements were made (Table 

 1): total length, standard length, preanus length, 

 predorsal length, prepelvic length, head length, 

 snout length, eye diameter, and body depth. All 

 references to lengths of larvae in text are to stan- 

 dard length unless otherwise noted. 



Osteology 



Sequence of ossification was determined from 10 

 specimens ranging from 5.2 to 25.3 mm SL. They 

 were cleared with trypsin and stained with 

 alizarin, using the method of Taylor (1967). 



DESCRIPTION 



Embryos 



Eight fertilized eggs from the plankton collec- 

 tions were preserved. The embryos were 

 approximately at the midstage of development at 

 the time of collection. Eggs were spherical, the 



661 



