FISHERY BULLETIN: VOL. 78. NO. 3 



by Hettler et al.^ This technique allows for a vol- 

 untary release of ova by females injected with 

 human chorionic gonadotropin (HCG) and sperm 

 by uninjected males. The quality of eggs produced 

 by this technique is far superior to injecting HCG 

 and manually removing and mixing gametes. The 

 rotifer Brachionus plicatilis, cultured in the 

 laboratory, was used as food for spot larvae till 

 they were approximately 30 d old. Zooplankton 

 captured from the field and predominated by 

 copepod nauplii and copepodites were sporadically 

 included in their diets during this period. Newly 

 hatched Artemia nauplii were used as food for 

 larvae older than about 30 d. Eggs and larvae were 

 maintained at temperatures and salinities of ca. 

 20° C and ca. 30-35%o. Some advanced larvae and 

 juveniles were collected with a modified neuston 

 net (Hettler 1979) near Beaufort, N.C. 



Two developmental series of larvae were used. 

 Specimens in the first series were used for compil- 

 ing morphometric data, describing pigment pat- 

 terns and illustrating larval stages. Those in the 

 second series were cleared with trypsin, stained 

 with a combination of alcian blue and alizarin red 

 according to Dingerkus and Uhler (1977), and 

 Taylor and Van Dyke"* and used for meristic 

 studies. Egg stages follow those described by 

 Ahlstrom and Ball (1954). The embryonic period 

 was divided into three stages: early (fertilization 

 to blastopore closure), middle (from blastopore clo- 

 sure until the tail twists out of the plane of the 

 embryonic axis), and late (from tail twisting to 

 hatching). Larval stages followed those described 

 by Ahlstrom et al. (1976). The larval period was 

 separated into the preflexion, flexion, and postflex- 

 ion stages associated with the development of the 

 caudal fin; the stages occurring before, during, 

 and after the upward fiexion of the notochord tip. 

 We also included a yolk-sac stage, which we be- 

 lieved should be treated separately. 



Pterygiophore nomenclature followed Houde 

 and Potthoff (1976). Nominal, full complement 

 counts were taken from Johnson (1978), although 

 we obtained pectoral ray counts directly from 15 

 specimens (University of North Carolina; UNC 



^'Hettler, W. F., A. B. Powell, and L. C. Clements. 

 1978. Laboratory induced spawning of spot, Leiostomus 

 xanthurus (Lacepedel. Annual Report of the Beaufort 

 Laboratory to the U.S. Department of Energy, p. 351-356. 



••Taylor, W. R., and G, C. Van Dyke. 1978. Staining and 

 clearing small vertebraes for bone and cartilage study. Unpubl. 

 manuscr., 19 p. National Museum of Natural History, Washing- 

 ton, DC 20560. 



563). Measurements from eggs and larvae pre- 

 served in 5% buffered Formalin^ are identified as 

 follows: 



Standard length (SL) — in preflexion and flex- 

 ion larvae, the horizontal distance from the tip of 

 the snout to the tip of the notochord. In postflexion 

 larvae, from the tip of the snout to the base of the 

 hypural plate. 



Preanus length — horizontal distance from the 

 tip of the snout to the posterior part of the anus. 



Head length — horizontal distance from the tip 

 of the snout to the posterior margin of the otic 

 capsules in yolk-sac larvae and the horizontal dis- 

 tance from the tip of the snout to the opercular 

 margin in other larvae and juveniles. 



Snout length — horizontal distance from the tip 

 of the snout to the anterior margin of the pig- 

 mented region of the eye. 



Eye diameter — maximum horizontal width of 

 the pigmented eye. 



Body depth — the vertical depth of the body 

 measured at the pectoral fin base exclusive of the 

 finfold. 



RESULTS 



Embryonic Development 



General 



Spot eggs are pelagic. The chorion was trans- 

 parent and unsculptured. The yolk was imseg- 

 mented, unpigmented, and the perivitelline space 

 narrow in live eggs. Oil globules were yellow. We 

 have obtained batches of eggs with almost all 

 single oil globules, almost all multiple oil 

 globules, or a gradient between these conditions. 

 Batches of eggs with single oil globules occurred 

 most commonly. When oil globules were multiple, 

 they were grouped together and not scattered 

 throughout the yolk. The maximum number of oil 

 globules observed was 12. Oil globules coalesced 

 during egg development and it appeared that only 

 one oil globule was present on newly hatched lar- 

 vae. Egg diameter averaged 0.80 mm and ranged 

 from 0.72 to 0.87 mm (N = 265). Oil globules, from 

 eggs with one oil globule, averaged 0.21 mm in 

 diameter and ranged from 0.18 to 0.28 mm (A'' = 

 86). The eggs hatched in about 48 h at 20° C. 



^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



702 



