GROWTH, MORTALITY, AND AGE/SIZE STRUCTURE OF THE 

 FISHERIES FOR TILEFISH, LOPHOLATILUS CHAMAELONTICEPS , 

 IN THE MIDDLE ATLANTIC- SOUTHERN NEW ENGLAND REGION 



S. C. Turner, ' C. B. Grimes, 2 and K. W. Able 3 

 ABSTRACT 



Otoliths of tilefish taken in 1 978 from the Middle Atlantic Bight and Southern New England region were used 

 to determine length at age and growth rates. Marginal increment analysis revealed that annuli were formed 

 once each year between March and May, and modes in the length- frequency histogram for small tilefish (<3 1 

 cm FL) in March-May agreed with back- calculated lengths at ages 1-3. Tilefish (sexes combined) grew about 

 1 cm FL per year for the first 4 years, and beyond that age males grew more rapidly than females. Maximum 

 size of females was 95 cmFL and of males 112 cmFL, and maximum ages were 35 and 26 years, respectively. 

 Von Bertalanffy growth formulae for both sexes were found to be significantly different with Hoetelling's T : . 

 Sex ratios at age generally were not significantly different from 1:1, and skewed sex ratios at length were 

 attributed to differential growth rates. No significant differences were found between males and females in 

 the regressions of both whole and eviscerated weights on length. 



Length-frequency histograms of tilefish from the longline fishery in 1974-80 showed truncation of the size 

 structure accompanied by a decrease in the size at full recruitment in more recent years. In 1974, 719i were 

 >70 cm FL, while in 1980 these largerfish made up about 19S of the catch. Length frequencies from three 

 fisheries in 1978 had a similar modal size (51-55 cm FL), but some differences in size structure. The rec- 

 reational and longline fisheries caught larger fish (37 and 53'7 , respectively, between 56 and 75 cm FL) than 

 the foreign trawl fishery ( 1 7 % at 56-75 cm FL and 5 1 % at 26-50 cm FL). The differences in length frequencies 

 were reflected in the age structures of the three fisheries, with the foreign trawls exploiting 3-7 year olds (9 1' i 

 of the catch), recreational anglers 4-9 year olds (98%), and longline 4-9 year olds (90%). 



The catch curve for the longline fishery was concave, probably the result of increased fishing pressure in 

 recent years. Estimates of the instantaneous rate of total mortality were 0.46 for the more linear portion of 

 the longline catch curve and 0.60 for the catch curve from the foreign trawl fishery. 



Tilefish, Lopholatilus chamaeleonticeps, are large (to 

 about 120 cm FL (fork length) and 30 kg], demersal 

 branchiostegids found along the outer continental 

 shelf in 80-540 m from Nova Scotia to Surinam 

 (Dooley 1978; Markle et al. 1980). In the Middle 

 Atlantic Bight and Southern New England waters 

 they have usually been found in temperatures of 9°- 

 14° C and depths of 100-2 40 m. 4 After a brief period 

 as pelagic larvae (Fahay and Berrien 1981; Berrien in 

 press), tilefish settle to the bottom. Both juvenile and 

 adult tilefish ranging in size from 10 or 20 cm FL to 



'Ecology Graduate Program, Rutgers University, New Brunswick, 

 N.J., 08903 and Northeast Fisheries Center Sandy Hook Labora- 

 tory, National Marine Fisheries Service, NOAA, Highlands, NJ 

 07732. 



•'Department of Horticulture and Forestry and New Jersey 

 Agricultural Experiment Station, Rutgers University, New 

 Brunswick, NJ 08903. 



'Department of Biological Sciences and Center for Coastal and 

 Environmental Studies, Rutgers University, New Brunswick, NJ 

 08903. 



4 Freeman, B. L., and S. C. Turner. 1977. Biological and fisheries 

 data on tilefish, Lopholatilus chamaeleonticeps Goode and 

 Bean. Tech. Ser. Rep. 5, 41 p. Northeast Fisheries Center Sandy 

 Hook Laboratory, National Marine Fisheries Service, NOAA, 

 Highlands, NJ 07732. 



> 1 m FL have been observed occupying vertical bur- 

 rows (Able et al. 1982), horizontal excavations in 

 submarine canyon walls called "pueblo villages" 

 (Cooper and Uzmann 1977; Warme et al. 1978), and 

 scour depressions around boulders (Valentine et al. 

 1980). Tilefish excavations appear to be local centers 

 of abundance for several species of crustaceans and 

 fish; thus through their burrowing activity, tilefish 

 may have considerable impact on outer continental 

 shelf communities (Able et aL 1982). 



Commercial exploitation of Middle Atlantic- 

 Southern New England tilefish began in 1915, and 

 landings have been made in nearly all years since that 

 time. Annual landings from this unit stock (Katz et al. 

 1983) have fluctuated from a peak of 4,500 metric 

 tons (t) landed in 10 mo in 1916 to<l t reported for 

 several years since then. Commercial landings have 

 risen during the 1970's, due to the development of a 

 longline fishery currently centered in New Jersey and 

 New York. Landings in 1977-80 (2,061, 3,412, 

 3,840, and 3,575 t, respectively) have exceeded all 

 years except 1916 for which information is available 

 (Freeman and Turner footnote 4; U.S. Department of 



Manuscript accepted February 1983. 

 FISHERY BULLETIN: VOL. 81, NO. 4. 1983. 



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