FISHERY BULLETIN: VOL. 74. NO. 1 



Peretti of the East African Freshwater Fisheries 

 Research Organization, Jinja, East Africa), and 

 the following species examined by one of the 

 authors (E.B.B.): in the deep living Pacific rattail 

 Coryphaenoides acrolepis (58 cm SL; 10 to 11 yr); 

 in the myctophids Stenobrachius leucopsarus, 

 Tarletonbeania crenularis, and Triphoturus mexi- 

 canus; in the freshwater fish Cottus asper and 

 Salmo gairdneri; in the tropical marine fish 

 Chromis atrilobata and Apogon retrosella; in 

 adults of the gobies Cleuelandia ios and Gil- 

 lichthys mirabilis, where clear growth checks also 

 occur, so that daily marks alone would lead to 

 distinct underestimates of age; and in four species 

 of rapidly growing tropical and temperate tunas. 

 Statoliths from the squid Loligo opalescens (both 

 wild caught adults and laboratory-reared juve- 

 niles) also show what appear to be growth layers 

 analogous to those in fish otoliths. The appear- 

 ance of growth interruptions in a number of 

 species, e.g., the rockfish (genus Sebastes), either 

 as winter checks, spawning checks, or apparently 

 dispersed more evenly throughout the year, may 

 impose a severe limitation upon the use of daily 

 marks to age these fish. The technique seems best 

 suited to larvae, juveniles, fast-growing species, 

 and tropical species. 



It is clear from our work that some difficulties 

 must be overcome before age estimation by means 

 of daily rings can become a standard tool in fish- 

 eries biology. However, it is also clear that 



1. Daily rings may be used to estimate the ages 

 of larvae of some species up to 100 days old 

 with very great precision and that they prob- 

 ably can be used for fish up to 1 yr of age, 

 perhaps with a smaller degree of precision. 

 Struhsaker and Uchiyama (1976) show simi- 

 lar results with the tropical engraulid Stole- 

 phorus purpureus. 



2. Daily marks may be used as a means of ac- 

 curate age determination for at least some 

 species of fish up to 6 yr old. 



3. Daily marks may be used for age determina- 

 tion of at least some tropical fish. Pannella's 

 (1974) suggestion that daily increments 

 might be used in tropical fish as a means of 

 age estimation is almost certainly true, and 

 should be applicable to most species. 



LITERATURE CITED 



Blacker, R. W. 



1974. Recent advances in otolith studies. In F. R. Harden 

 Jones (editor), Sea fisheries research, p. 67-90. John Wiley 

 and Sons, N.Y. 



BROTHERS, E. B. 



1975. Comparative ecology and behavior of three sjonpatric 

 California gobies. Ph.D. Thesis, Univ. California, San 

 Diego, 370 p. 



DEGENS, E. T, W. G. DEUSER, AND R. L. HAEDRICH. 



1969. Molecular structure and composition offish otoliths. 

 Mar Biol. (Berl.) 2:105-113. 



Lasker, R., H. M. Feder, G. H. Theilacker, AND R. C. May. 



1970. Feeding, growth, and survival of Engraulis mordax 

 larvae reared in the laboratory. Mar. Biol. (Berl.) 

 5:345-353. 



LEONG, R. 



1971. Induced spawning of the northern anchovy, En- 

 graulis mordax Girard. Fish. Bull., U.S. 69:357-360. 



MATHEWS, C. P. 



1975. Some observations on the ecology and the population 

 dynamics of Merluccius angustimanus in the south Gulf 

 of California. J. Fish. Biol. 7:83-94. 



In press. The biology, ecology and population dynamics 

 of the large Gulf of California hake. Symposium in 

 Fisheries Biology, Ensenada, B.C., Mexico. Ciencas 

 Marinas, Spec. Suppl. 

 PANNELLA, G. 



1971. Fish otoliths: daily growth layers and periodical 



patterns. Science (Wash., D.C.) 173:1124-1127. 

 1974. Otolith growth patterns: An aid in age determina- 

 tion in temperate and tropical fishes. In T B. Bagenal 

 (editor), The ageing of fish, p. 28-39. Unwin Brothers, 

 Ltd., Surrey. 

 SCOFIELD, E. C. 



1931. The striped bass of California (Roccus lineatus). 

 Calif. Dep. Fish Game, Fish Bull. 29, 84 p. 

 STRUHSAKER, P., AND J. H. UCHIYAMA. 



1976. Age and growth of the nehu, Stolephorus purpureus 

 (Pisces: Engraulidae), from the Hawaiian Islands as indi- 

 cated by daily growth increments of sagittae. Fish. Bull., 

 U.S. 74:9-17. 



WlLLUMS, T., AND B. C. BEDFORD. 



1974. The use of otoliths for age determination. In T. B. 

 Bagenal (editor). The ageing offish, p. 114-123. Unwin 

 Brothers, Ltd., Surrey. 



8 



