STANDARD and CHITTENDEN: REPRODUCTION. MOVEMENT. AND POPULATION OF BANDED DRUM 



larval fish in the periods April-June and August- 

 October between Cape Lookout and Chesapeake 

 Bay (Berrien pers. commun. footnote 7 in Powles 

 1980). This bimodal pattern, moreover, is similar 

 to findings of distinct spring- and fall-spawning 

 periods in other Gulf fishes such as Cynoscion 

 arenarius (Shlossman and Chittenden 1981), C. 

 nothus (DeVries and Chittenden 1982), and Pep- 

 rilus burti (Murphy 1981). Murphy and Chitten- 

 den 7 integrated biological findings with hydro- 

 graphic data of Kelly and Randall* and suggested 

 hydrographic reasons for this pattern in P. burti 

 and C. nothus, which probably apply also to L. 

 fasciatus and many other species: spawning is 

 timed to coincide with the periodicity of downcoast 

 alongshore currents (toward Mexico) and onshore 

 Ekman transport at the surface. These 

 phenomena probably transport pelagic eggs and 

 larvae inshore and "downstream" to nurseries in 

 the northwestern Gulf from spawning grounds lo- 

 cated "upstream" in or toward the north central 

 Gulf. Current transport mechanisms reverse in 

 the summer (a variable period but about mid- 

 June-early August) and would carry pelagic eggs 

 and larvae offshore, which presumably is un- 

 favorable to survival in many species, or toward 

 the north central Gulf. If spawning is substantial, 

 and successful, during summer, our length- 

 frequency data and those for the other species 

 cited indicate summer-spawned individuals do not 

 subsequently appear in the northwestern Gulf. 

 Presumably, their existence would be reflected as 

 unimodal, or at least not clearly bimodal, length 

 frequencies when adequate data become available 

 for the north central Gulf. 



Our finding that the few spring-spawned fish 

 disappeared after August at 3-5 mo of age agrees 

 with Hildebrand and Cable (1934) who collected 

 what must have been spring-spawned fish in July 

 (x = 34 mm, range 3-70 mm ?L) and August (x = 

 54 mm, range 3-77 mm ?L) off North Carolina and 

 noted they were absent later. Because the mag- 

 nitude of spring spawning appears so small, for 

 practical stock assessment purposes, our data 

 could just as well be interpreted as one long period 



7 Murphy. M. D.. and M. E. Chittenden. Jr. Unpubl. manu- 

 scr. Reproduction, movements, and population dynamics of the 

 gulf butterfish, Peprilus burti. 66 p. Marine Research 

 Laboratory, Florida Department of Natural Resources, 100 

 Eighth Avenue, S.E.. St. Petersburg. FL 33701. 



H Kelley. F. J., Jr., and R. E. Randall. 1980. Physical 

 oceanography. In R. W. Hann, Jr. and R. E. Randall (editors >. 

 Evaluation of brine disposal from the Bryan Mound .te of the 

 Strategic Petroleum Reserve Program, p. (l-l)-(l-93). National 

 Technical Information Service, Springfield, VA 22150 (DOE/ 

 P010114-1). 



with little or no spawning from April to August. It 

 seems more meaningful, however, to regard the 

 spawning of L. fasciatus as occurring during two 

 discrete periods because Murphy and Chittenden 

 (footnote 7) suggested a hydrographic basis for 

 that pattern. 



Our findings are new that fall-spawned groups 

 spawn in both spring and fall periods and that 

 spring spawning is the product offish about 20 mo 

 old. Shlossman and Chittenden (1981) noted that 

 temporal isolation of spawned groups in C. 

 arenarius implied reproductive isolation and 

 might indicate separate populations. The tempor- 

 ally separate spawned groups in L. fasciatus, how- 

 ever, are not reproductively isolated and appar- 

 ently do not form separate populations because the 

 same spawned group spawns in both periods. This 

 simplifies management, because separate data 

 may not be necessary for both spawning periods, 

 especially considering that one is very small. 



Shlossman and Chittenden (1981) and DeVries 

 and Chittenden (1982) noted that the existence of 

 two spawned groups in C. arenarius and C. nothus 

 might buffer population stability as a multiple 

 year class structure does in longer lived species. In 

 L. fasciatus, however, the contribution that 

 spring-spawned groups make to total population 

 size is probably too small to buffer fluctuations at 

 any reasonably "normal" stock size. 



Bathymetric Distribution 



Larimus fasciatus primarily is restricted to the 

 inner continental shelf. Our finding, that they 

 range from <5 to 55 m but are most common from 

 5 to 16 m, agrees with Hildebrand (1954), Miller 

 (1965), Burns (1970), Milstein and Thomas (1976). 

 and Wenner et al. (1979a, b). Franks et al. (1972) 

 captured most specimens in 37-55 m off Missis- 

 sippi which supports Chittenden and McEachran's 

 (1976) suggestion that the white shrimp commun- 

 ity, of which L. fasciatus is a member, penetrates 

 into deeper water in the north central Gulf than it 

 does in the northwestern area. However, Springer 

 and Bullis (1956) collected fish at 106 m off both 

 Mississippi and Texas. 



Age Determination and Growth 



Little literature exists on age determination 

 and growth in L. fasciatus. We determined age by 

 length-frequency analysis because our data came 

 from a long-term set of cruises close enough to- 

 gether in time that modes were easily followed. 



359 



