FISHERY BULLETIN: VOL. 81, NO. 3 



N.C. 



'O .# 



&^ , 7 CAPE LOOKOUT 



^ V 



X 



J_ 



I 



L 



_L 



1 



37°00 



36°00' 



35°00 



34°00' 



33°00 



32°00 



-31°00 



81°00' 80°00' 79°00' 78°00 77°00' 76°00' 75°00' 



FIGURE 1. — Distribution of Caulolatilus microps off North Carolina and South Carolina (noted by hatch marked area). 



1972 to 1977 in the northern and central portions of 

 Onslow Bay aboard the RV Onslow Bay (NMFS). 

 Fishing was most successful when baits were main- 

 tained as close to the bottom as possible. Total length 

 (TL, mm) and total weight (W, g) were recorded for 

 each fish, gonads excised and stored in 10% For- 

 malin 6 and otoliths removed and stored in glycerine. 

 Sampling of headboats fishing out of North Carolina 

 and South Carolina ports provided ancillary records 

 of total length and total weight, and samples of 

 gonads and otoliths. 



A gonosomatic index (GSI) was calculated accord- 

 ing to the formula 



GSI 



GW 

 W 



X 100 



''Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



where GW = preserved gonad weight (0. 1 g) and W = 

 total body weight (g). GSI was used to determine 

 spawning seasonality and sexual maturity. 



Sex was determined by gonad examination since 

 blueline tilefish apparently exhibit no sexually 

 dimorphic characteristics. Ovaries and testes were 

 staged macroscopically and histologically after pre- 

 servation in 10% Formalin (Tables 1, 2). Ova stages 

 corresponded to those described by Moe (1969) for 

 red grouper, Epinephelus morio: oogonia, 2-8 jtx; stage 

 I, early oocytes, 20-50 /i; stage II, previtellogenic 

 oocytes, 40-170 fi; stage III, early vitellogenic 

 oocytes, 110-260 ju; stage IV, active vitellogenic 

 oocytes, 215-650//.; stage V, mature ova, 735-910 /x 



554 



