patterns for commercially important groundfishes of the 

 Pacific Northwest coast of North America. Pac. Mar. Fish. 

 Comm. Bull. 4:1-66. 

 Alverson, D. L., a. T. Pruter, and L. L. Ronholt. 



1964. A study of demersal fishes and fisheries of the north- 

 eastern Pacific Ocean. H. R. MacMillan Lectures in 

 Fisheries, Inst. Fish., Univ. B.C., 190 p. 



Byrne, J. V., and D. A. Panshin. 



1968. Continental shelf sediments off Oregon. Oreg. State 

 Univ. Sea Grant E.\t. Mar. Advis. Program 8, 4 p. 

 Day, D. S., and W. G. Pearcy. 



1968. Species associations of benthic fishes on the continen- 

 tal shelf and slope off Oregon. J. Fish. Res. Board Can. 

 25:2665-2675. 



DeGroot, S. J. 



1971. On the interrelationships between morphology of the 

 alimentary tract, food and feeding behaviour in flatfishes 

 (Pisces: Pleuronectiformes). Neth. J. Sea Res. 5:121-196. 



Forrester, C. R. 



1969. Life history information on some groundfish species. 

 Fish. Res. Board Can., Tech. Rep. 105, [17 p.] 



Forrester, C. R., and J. A. Thomson. 



1969. Population studies on the rock sole (Lepidupaetta 

 bilineata) of northern Hecate Strait, British Columbia. 

 Fish. Res. Board Can., Tech. Rep. 108, 104 p. 

 Hart, J. L. 



1973. Pacific fishes of Canada. Fish. Res. Board Can.. Bull. 

 180, 740 p. 

 HOBSON, E. S. 



1965. Diurnal-nocturnal activity of some inshore fishes in 

 the Gulf of California. Copeia 1965:291-302. 



HORN,H.S. 



1966. Measurement of "overlap" in comparative ecological 

 studies. Am. Nat. 100:419-424. 



Jones, D. A., N. Peacock, and 0. F. M. Phillips. 



1973. Studies on the migration of Tritaeta gihbosa, a 

 subtidal benthic amphipod. Neth. J. Sea Res. 7:135-149. 

 Ketchen, K. S., and C. R. Forrester. 



1966. Population dynamics of the petrale sole, Eopaetta 

 Jordan i, in the waters of western Canada. Fish. Res. 

 Board Can., Bull. 153, 195 p. 

 MacArthur, R. H., and E. R. Pianka. 



1966. On optimal use of a patchy environment. Am. Nat. 

 100:603-609. 

 Norman, J. R. 



1934. A systematic monograph of the flatfishes 

 (Heterosomata). Vol. I. Psettodidae, Bothidae, 

 Pleuronectidae. Br. Mus. (Nat. Hist.), Lond., 459 p. 

 Pearcy, W. G., and H. A. Vanderploeg. 



1973. Radioecology of benthic fishes off Oregon. In 

 Radioactive contamination of the marine environment, p. 

 245-261. Int. At. Energy Agency, Vienna. 

 Rae, B. B. 



1969. The food of the witch. Mar. Res. Dep. Agric. Fish. 

 Scotl. 2, 23 p. 

 Shubnikov, D. a., and L. A. Lisovenko. 



1964. Data on the biology of rock sole of the southeastern 

 Bering Sea. Tr. Vses. Nauchno-issled. Inst. Morsk. Rybn. 

 Khoz. Okeanogr. 49 (Izv. Tikhookean. Nauchno-issled. 

 Inst. Morsk. Rybn. Khoz. Okeanogr. 51): 209-214. (Transl. 

 in Soviet Fisheries Investigations in the Northeast Pacific, 

 Part II, p. 220-226, by Israel Program Sci. Transl., 1968, 

 available Natl. Tech. Inf. Serv., Springfield, VA, as TT 

 67-51204.) 



Stickney, R. R., G. L. Taylor, and R. W. Heard III. 



1974. Food habits of Georgia estuarine fishes. I. Four 

 species of flounders (Pleuronectiformes: Bothidae). Fish. 

 Bull., U.S. 72:515-525. 

 Tyler, A. V. 



1973. Alimentary tract morphology of selected North At- 

 lantic fishes in relation to food habits. Fish. Res. Board 

 Can., Tech. Rep. 361, 23 p. 

 Yazdani.G. M. 



1969. Adaptations in the jaws of flatfish (Pleuro- 

 nectiformes). J. Zool. (Lond.) 159:181-222. 



Michael J. Kravitz 



William G. Pearcy 



M. P. Guin 



School of Oceanography 



Oregon State University 



CorvaUis. OR 97331 



AGE DETERMINATION OF A TROPICAL 



REEF BUTTERFLYFISH UTILIZING 

 DAILY GROWTH RINGS OF OTOLITHS 



The recent economic expansion of the aquarium 

 fish industry in Hawaii has raised questions con- 

 cerning the judicious exploitation of reef resources 

 (Pellegrin 1973; Randall 1973; Reese 1973). How- 

 ever, appropriate management strategies cannot 

 be implemented until sufficient biological data 

 have been gathered, allowing a characterization of 

 exploited populations of fishes. The relative 

 paucity of such information concerning the vast 

 majority of reef species underscores the need for 

 future research. 



Studies pertaining to the age and growth of 

 fishes are especially useful in the analysis of 

 exploited stocks. Unfortunately, efforts to age 

 tropical fishes in the past have proved to be largely 

 unsuccessful and/or involve considerable expen- 

 ditures in time and effort (Pannella 1974). How- 

 ever, the recent studies of Pannella (1971, 1974) 

 have initiated the development of a technique for 

 determining the age of tropical fishes without 

 having to resort to more elaborate approaches such 

 as the Peterson method of ageing. Panella has 

 provided evidence that many species of both tem- 

 perate and tropical fishes deposit lamellae on their 

 otoliths with a diel periodicity. These lamellae are 

 visible as rings or circuli after the otolith has been 

 properly prepared. In the absence of annuli, these 

 rings may be used to age fish. A recent investiga- 

 tion by Struhsaker and Uchiyama (1976) using this 

 technique was successful in ageing the Hawaiian 



990 



