Sogard et al Early life history of Tautoga onitis in the Mid-Atlantic Bight 



535 



pelagic larval stage was remarkably similar, with a 

 mean of 20.4 (SD 2.7). Assuming that the first incre- 

 ment is deposited at about the time of hatching, tautog 

 spend 3 weeks in the plankton before settling to the 

 benthos. Subtraction of total increments from the date 

 of collection resulted in a wide spread of estimated birth 

 (hatch) dates, with a mean of 4 June and a range of 

 17 April-22 July. These dates are consistent with the 

 general timing of the collection of eggs and larvae 

 (Tables 2, 3). Settlement dates, estimated by subtract- 

 ing only the juvenile-stage incre- 

 ments from the date of capture, 

 were correspondingly wide- 

 spread, with a mean of 25 June 

 and a range of 6 May-13 August. 



creased in number in August collections. By Septem- 

 ber, the young-of-the-year dominated the trawl samples 

 while decreasing in throw-trap sampling. 



Modal progression of length-frequency distributions 

 demonstrated relatively rapid growth for both young- 

 of-the-year and 1 -year-old tautog during the summer 

 months. In contrast, comparison of young-of-the-year 

 sizes in October with 1 -year-old lengths in June in- 

 dicated only minor growth during the fall, winter, and 

 spring. Juvenile tautog attained a size of 40-100 mm 



Juvenile habitat, size 

 composition, and growth 



In throw-trap samples collected 

 in the shallow waters of Great 

 Bay and Little Egg Harbor, juve- 

 nile tautog were collected only on 

 vegetated substrates, and were 

 more abundant in sea lettuce 

 (Ulva lactuca, n 19) than in eel- 

 grass (Zostera marina, n 2) (So- 

 gard and Able 1991). Juveniles 

 <40mm in length were rare in 

 the deeper waters sampled by 

 trawls, but the larger young-of- 

 the-year and 1 -year-old tautog 

 collected by trawling were most 

 abundant in eelgrass beds. Of 14 

 sampling stations throughout 

 Great Bay and Little Egg Har- 

 bor, two were in eelgrass habi- 

 tats. These two stations ac- 

 counted for 69% of the 235 tau- 

 tog collected by trawling in 1988 

 and 1989. 



Combined length-frequency 

 data from throw-trap sampling 

 and trawling efforts suggested 

 that most tautog in the Great 

 Bay-Little Egg Harbor system, 

 based on these sampling techni- 

 ques, belonged to one of two 

 year-classes (Fig. 6). Young-of- 

 the-year first appeared in July, 

 primarily in the shallower (< 1 m) 

 habitats sampled by throw trap- 

 ping. In the deeper areas (> 1 m) 

 sampled by otter trawl, larger 

 young-of-the-year fishes in- 



60' 



40 



20 



60 

 40 

 20 



60 

 W 



_i 



< 40- 

 Q 



> 20- 



Q 



Z 



fe 60 

 EC 



m 40 

 m 



^ 20 



60 

 40 



20 H 



NOVEMBER, 

 MARCH, APRIL, MAY 



■ PLANKTON NET 

 n THROW TRAP 

 D TRAWL 



JUNE 



^FHr 



JULY 



rln^-,- , r-n^EPqnrii— ir-,r— I 



II 



FJHr 



AUGUST 



B. 



SEPTEMBER 



H^p 



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OCTOBER 



^^ — ^ ■ F^^ F^ ^ 



5 25 45 65 85 105 125 145 165 185 205 225 245 265 

 STANDARD LENGTH (mm) 



Figure 6 



Length-frequency distributions of Tautoga onitis collected in the Little Egg Harbor- 

 Great Bay estuarine system. Plankton samples were collected on a weekly basis 

 throughout the year. Throw-trap samples were collected from shallow habitats (< 1 m 

 at low tide), May-October; trawl samples were collected from deeper habitats (1-8 m) 

 monthly, with no tautog collected during December-February. 



