Table 3. — Effects of carp pituitary onyellowtail flounder receiving daily injections. All fish were exposed to llL:13Dphotoperiod and 

 water temperatures of 8.5°-12.5°C (Mean 10.1°C). Symbols: + = did, = did not hydrate or ovxilate. 



Dosage 



No of 

 Injec- 

 tions 



Total 

 length 

 (mm) 



Initial 

 body weight 



(g) 



Weight change 

 ("o initial wt) 



GSI 

 (°o final wt) 



Date of Fertili- 



fcftect spawning zation Hatch 



Hydrated Ovulated 1977 (%) (%) 



2.0 mg/kg fish 



Controls 



5 



6 



5 

 3 



+ 0.56 

 + 9.13 

 + 470 



+ 7.16 

 + 2.04 



+ 0.97 



+ 1.62 



+ 2.79 

 + 3.17 



+ 2.16 

 + 2.79 



+ 1,92 

 *2 19 



46 



21.2 



6.9- 



20.8 

 5.3 



10.7 

 B.8 



7.7 



93 

 18.0 

 18.9 

 167 

 18.4 



+ ' 



+ 



+ 



+ 

 + 





 

 

 



Apr 12 



75 



80 



70 

 75 



60 

 40 

 45 

 55 

 65 

 60 

 55 

 60 

 80 



'Died: Stage III ova in ovaries 



pigmented at 1 day and the mouth was functional 

 at 1-3 days after hatching. No abnormahties were 

 observed in hormone-induced larvae. 



Twenty larvae were sampled weekly (Table 4). 

 The specific growth rates for the 63-day period 

 from first feeding averaged 9.9T7(,day for dry 

 weight (micrograms) and 2.759^ standard length 

 (millimeters). The first fish metamorphosed 54 

 days after hatching at 17.00 mm standard length. 

 By the 63d day after hatching, all the larvae had 

 completed metamorphosis, and average length 

 was 17.40 mm. 



Wild copepod nauplii were collected daily from a 

 nearby estuary and fed to the larvae after being 

 sieved to obtain the proper particle size. Larvae of 

 the yellowtail flounder required small food or- 

 ganisms (<100/xm in largest dimension) to in- 

 itiate feeding. The most difficult aspect of rearing 

 the larvae was the problem of obtaining enough 

 food organisms in the size range required. Larval 

 mortality was high for the first 2 wk of feeding, 

 possibly caused by starvation. However, yellow- 

 tail flounder larvae are able to survive for consid- 



T.ABLE 4. — Size of yellowtail flounder larvae reared artificially 

 at 10°C from hac ing to metamorphosis. Average sizes of 20 

 larvae are followed by standard deviation. 



erable periods of days without exogenous food. 

 Some larvae were maintained at 8°C and fed suc- 

 cessfully and survived after being deprived of food 

 for 10 days after hatching (Smigielski unpubl. 

 data). As the larvae increased in size through 

 metamorphosis, larger food organisms such as 

 adult copepods, the rotifer Branchion us plicatilis, 

 and the brine shrimp, Artemia sp., were offered. 



Acknow ledgments 



The author expresses his appreciation to Hugh 

 Poston of the Tunison Laboratory of Fish Nutrition, 

 Cortland, N.Y., and Geoffrey C. Laurence of 

 the Northeast Fisheries Center Narragansett 

 Laboratory, National Marine Fisheries Service, 

 NOAA for their many helpful criticisms of the 

 manuscript, and Kathy Dorsey and Thomas 

 Halavik for their technical assistance. 



Literature Cited 



BIGELOW, H. B., AND W. C. SCHROEDER. 



1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. Serv., 

 Fish. Bull. 53, 577 p. 



Clemens, H. P., and F. B. Grant. 



1964. Gonadal hydration of carp [Cyprinus carpio) and 

 goldfish iCarassius auratus) after injections of pituitary 

 extracts. Zoologica (N.Y.) 49:193-210. 

 COLTON, J. B., Jr. 



1972. Temperature trends and the distribution of 

 groundfish in continental shelf waters. Nova Scotia to 

 Long Island. Fish Bull., U.S. 70:637-657. 



Colton, J. B., Jr., and R. R. Marak. 



1969. Guide for identifying the common planktonic fish 

 eggs and larvae of Continental Shelf waters, Cape Sable to 

 Block Island. U.S. Bur. Commer. Fish., Biol. Lab., 

 Woods Hole, Mass., Lab. Ref. 69-9, 43 p. 



935 



