fin 1-21-24; midlateral scales, 75 Evermann (18961, Miller and Lea .... feeding when offered food and were alive at the ..... Reynolds, W. W., D. A. Thompson, and.
REFERENCECOPY
Biological Report 82(11.28) February, 1 9 8 5
Do Not Remove from the Library U. S. Fish rind Wilcilif~q p r v i ~ p National Wetlands Researrh Cer?%Wl EL-82-4 700 Cajun Dome Eoule. ...nrd La fayette, Louisiana 73536
Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest)
CALIFORNIA GRUNION
Fish and Wildlife Service U.S. Department of the Interior
Coastal Ecology Group Watetwavs Ex~erimentStation U.S. Army Corps of ~nginee;
T h i s i s one o f t h e f i r s t r e p o r t s t o be p u b l i s h e d i n t h e new " B i o l o g i c a l R e p o r t i i s e r i e s . T h i s t e c h n i c a l r e p o r t s e r i e s , p u b l ished b y t h e R e s e a r c h and D e v e l o p m e n t b r a n c h o f t h e U.S. F i s h a n d W i l d l i f e S e r v i c e , r e p l a c e s t h e "FWS/OBSii s e r i e s p u b l i s h e d f r o m 1976 t o September 1984. The B i o l o g i c a l Report s e r i e s i s designed f o r t h e r a p i d p u b l i c a t i o n o f r e p o r t s w i t h an a p p l i c a t i o n o r i e n t a t i o n , and i t c o n t i n u e s t h e f o c u s o f t h e FWS/OBS s e r i e s on r e s o u r c e management i s s u e s and f i s h a n d w i I d 1 if e needs.
B i o l o g i c a l Report 82(11.28) TR EL-82-4 February 1985
Species P r o f i l e s : L i f e H i s t o r i e s and Environmental Requirements o f Coastal Fishes and I n v e r t e b r a t e s ( P a c i f i c Southwest)
CALIFORNIA GRUNION
Ronald A. F r i tzsche, Robert H. Chamberlain and Robert A. F i s h e r Department o f F i s h e r i e s Humboldt S t a t e U n i v e r s i t y Arcata, CA 95521
P r o j e c t Manager L a r r y Shanks Project Officer John Parsons N a t i o n a l Coastal Ecosystems Team U.S. F i s h and W i l d l i f e S e r v i c e 1010 Gause Boulevard S l i d e l l , LA 70458 Performed f o r Coastal Ecology Group Waterways Experiment S t a t i o n U. S. Army Corps o f Engineers Vicksburg, MS 39180 and N a t i o n a l Coastal Ecosystems Team D i v i s i o n o f B i o l o g i c a l Services Research and Development F i s h and W i l d l i f e S e r v i c e U.S. Department o f t h e I n t e r i o r Washington, DC 20240
T h i s s e r i e s s h o u l d be r e f e r e n c e d as f o l l o w s : 1983-19-. Species p r o f i l e s : 1 i f e h i s t o r i e s U.S. F i s h and W i l d l i f e S e r v i c e . U. S. and e n v i r o n m e n t a l r e q u i r e m e n t s of c o a s t a l f i s h e s and i n v e r t e b r a t e s . F i s h W i l d l . Serv. B i o l . Rep. 82(11). U.S. Army Corps o f Engineers, TR EL82-4. T h i s p r o f i l e s h o u l d be c i t e d as f o l l o w s : F r i tzsche, R.A. , R. H. Chamberlain, and R. A. F i s h e r . 1985. Species p r o f i l e s : 1 i f e h i s t o r i e s and environmental r e q u i r e m e n t s o f c o a s t a l f i s h e s and i n v e r t e b r a t e s ( P a c i f i c Southwest) -- C a l i f o r n i a g r u n i o n . U. S. F i s h W i l d l . Serv. U.S. Army Corps o f Engineers, TR EL-82-4. 12 pp. B i o l . Rep. 82(11.28)
PREFACE This species p r o f i l e i s one o f a s e r i e s on c o a s t a l a q u a t i c organisms, p r i n c i p a l l y fish, o f s p o r t , commerci a1 , o r e c o l o g i c a l importance. The p r o f i l e s a r e designed t o p r o v i d e coastal managers, engineers, and b i o l o g i s t s w i t h a b r i e f comprehensive sketch o f t h e b i 01 og i c a l c h a r a c t e r i s t i c s and environmental r e q u i r e ments of t h e species and t o d e s c r i b e how p o p u l a t i o n s o f t h e species may be Each expected t o r e a c t t o environmental changes caused by c o a s t a l development. p r o f i l e has s e c t i o n s on taxonany, 1 i f e h i s t o r y , e c o l o g i c a l r o l e , environmental A three-ring binder i s requirements, and economic importance, i f appl i c a b l e. used f o r t h i s s e r i e s so t h a t new p r o f i l e s can be added as they are prepared. This p r o j e c t i s j o i n t l y planned and financed by t h e U.S. Army Corps o f Engineers and t h e U.S. F i s h and W i l d l i f e Service. Suggestions o r q u e s t i o n s of t h e f o l 1owing addresses.
regarding t h i s r e p o r t
should be
I n f o r m a t i o n T r a n s f e r Special i s t National Coastal Ecosystems Team U.S. F i s h and W i l d l i f e Service NASA-Sl i d e l 1 Computer Compl ex 1010 Gause Boulevard Sl i d e l 1 , LA 70458
U.S. Army Engineer Waterways Experiment S t a t i o n A t t e n t i o n : WESER-C Post O f f i c e Box 631 Vicksburg, MS 39180
d i r e c t e d t o one
CONTENTS
............ ....... . . . . . . . NOMENCLATURE/TAXONOMY/RANGE . .
................... ................... . . . . . . . . . . . . . . . . . . . ................... MORPHOLOGY/IDENTIFICATION AIDS . . . . . . . . . . . . . . . . . . . . REASON FOR INCLUSION I N SERIES . . . . . . . . . . . . . . . . . . . LIFE HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spawning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fecundity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ova Development . . . . . . . . . . . . . . . . . . . . . . . . . . L a r v a l . P o s t l a r v a l . and J u v e n i l e Stages . . . . . . . . . . . . . . Adults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ma t u r i t y and L i f e Span . . . . . . . . . . . . . . . . . . . . . . GROWTH CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . COMMERCIALANDSPORTFISHERIES . . . . . . . . . . . . . . . . . . . PREFACE CONVERSION TABLE ACKNOWLEDGMENTS .
ECOLOGICAL ROLE . . . . . . . ENVIRONMENTAL REQUIREMENTS . T i d a l Cycle . . . . . . . . Temperature . . . . . . . . Salinity Light O t h e r Environmental F a c t o r s
. . . . .......... ........... . LITERATURE CITED . . . . . . .
. . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................. .................. .................. ..................
iii v vi
10
CONVERSION TABLE M e t r i c t o U.S.
Customary To O b t a i n
m i l 1 i m e t e r s (mn) centimeters ( an) meters (m) k i 1 ometers ( km)
inches inches feet m i l es
2
square meters (m ) square k i 1 ometers ( km2) hectares (ha)
10.76 0.3861 2.471
square f e e t square m i l e s acres
l i t e r s (1) c u b i c meters (m3) c u b i c meters
gal 1 ons cubic f e e t acre-feet
m i l 1 igrams (mg) grams ( g ) k i l ograms ( k g ) m e t r i c tons ( t ) m e t r i c tons k i 1 ocal o r i e s ( kcal )
ounces ounces pounds pounds s h o r t tons British thenal units 1 . 8 ( " ~ ) + 32
Cel s i u s degrees U.S. inches inches feet ( f t ) f a thoms miles (mi) nautical miles ( m i ) square f e e t ( f t 2 ) acres 2 square m i l e s (mi )
Customary t o M e t r i c 25.40 2.54 0.3048 1.829 1.609 1.852
m i l 1 imeters centimeters meters meters k i l ometers k i 1 ometers
square meters hectares square k i l o m e t e r s
0.0929 0.4047 2.590
gal 1ons ( g a l ) cubic f e e t ( f t 3 ) acre-feet ounces ( o z ) pounds ( I b ) short tons ( t o n ) B r i t i s h thermal u n i t s ( B t u ) Fahrenheit degrees
Fahrenheit degrees
1it e r s c u b i c meters c u b i c meters 28.35 0.4536 0.9072 0.2520 0.5556(" F
grams k i 1 og rams m e t r i c tons k i 1 ocal o r i e s
-
32)
Cel s i u s degrees
ACKNOWLEDGMENTS We a r e g r a t e f u l f o r t h e r e v i e w s b y R o b e r t N. Lea, C a l i f o r n i a Department o f F i s h and Game, and R o b e r t J. Lavenberg, N a t u r a l H i s t o r y Museum o f Los Angeles County. Thomas H a s s l e r ( C a l i f o r n i a C o o p e r a t i v e F i s h e r y Research U n i t ) k i n d l y a c t e d as t h e l i a i s o n w i t h t h e N a t i o n a l C o a s t a l Ecosystems Team and g r e a t l y f a c i l i t a t e d t h e completion o f t h i s report.
Figure 1.
California grunion.
CALIFORNIA GRUNIOI\I
........... .... ...... ...................... ..................... .......
Scientific name Leuresthes tenuis (Ayres) Preferred common name.. .California grunion (Figure 1) Other comnon names Grunion, smelt Class Osteichthyes Order Atheriniformes Family Atherinidae (Silversides) Geographic range: coastal waters from San Francisco, Cal iforni a, to Magdalena Bay, Baja Cal ifornia; uncommon north of Point Conception (Figure 2).
rakers 5-7 + 28-29; vertebrae 47-50. Body elongate and slender; eye diameter equal to snout length; maxillary not reaching pupil; premaxi llary protrusible; jaw teeth lacking or minute; anal fin begins below 1st dorsal fin; scales between dorsal fins 7-9. Color in life: greenish above, with a silver-blue lateral stripe; silvery below; bluish blotch on cheek. REASON FOR INCLUSION IN SERIES hand
Dorsal fin V-VI I + I ,9-10; anal fin 1-21-24; midlateral scales, 75 (Moffatt and Thompson 1978a); gill
California grunion are caught by by sport fishermen during the
' ~ a r ~ e extracted l~ from Jordan and Evermann (18961, Miller and Lea (1972), and Eschmeyer et al. (1983).
CALIFORNIA
PACIFIC OCEAN
LOS ANGELES
Recorded spawning a r e a s
MILES -
O
0
SO
100
KILOMETERS
F i g u r e 2. D i s t r i b u t i o n o f the C a l i f o r n i a grunion the United States.
along the C a l i f o r n i a
c o a s t of
open season when t h e f i s h spawn on beaches above t h e s u r f l i n e a t n i g h t ( s e e L I F E HISTORY). The commercial catch o f grunion i s taken i n c i d e n t a l l y w h i l e f i s h i n g f o r o t h e r s p e c i e s and i s m a r k e t e d f r e s h as " s m e l t . " Limited q u a n t i t i e s a r e used f o r l i v e b a i t . LIFE HISTORY Spawning The g r u n i o n ' s unique spawning hab i t s have 1ong been r e c o g n i z e d and i t has been c a l l e d t h e " f i s h t h a t spawns on l a n d . " Through t h i s unusual b e h a v i o r , t h e C a l i f o r n i a g r u n i o n has traded numerous marine p e r i l s f o r f e w e r t e r r e s t r i a l hazards, and t h e r e b y improved t h e p r o b a b i 1 i t y of egg s u r v i v a l (Thompson 1919). The spawning season begins i n l a t e February o r e a r l y March and may e x t e n d t o e a r l y September; peak spawning i s i n A p r i l and May ( C l a r k 1925). The p r o t r a c t e d season may v a r y f r o m y e a r t o y e a r b y s e v e r a l months ( W a l k e r 1952). Most f e m a l e s i n t h e i r t h i r d y e a r of l i f e (age-group 1 1 ) b e g i n spawning e a r l y i n t h e season ( A p r i l - M a y ) , whereas f i s h i n t h e i r second y e a r o f 1 i f e (ageg r o u p I ) spawn somewhat l a t e r (MayJune). According t o C l a r k (19251, about 30% of t h e f e m a l e s w i l l have spawned i n March, 75% b y l a t e A p r i l , and 90% b y e a r l y May. The r e m a i n i n g 10% spawn f r o m May t o September. In l a t e J u l y , o n l y 7% o f t h e females examined c o n t a i n e d m a t u r e ova, and i n l a t e August o n l y i m a t u r e ova were observed ( C l a r k 1925). G r u n i o n spawn as f a r n o r t h as New Sr i g h t o n S t a t e Beach, M o n t e r e y Bay ( S p r a t t 1981) and as f a r s o u t h as Mexico. The 1a r g e s t g r u n i o n spawning runs r e p o r t e d by S p r a t t (1971) are the beaches i n typically along southern C a l i f o r n i a ( F i g u r e 2). I n g r u n i o n spawning w a t e r s t h e r e a r e t w o h i g h and two low t i d e s d a i l y . The h i g h e r o f t h e h i g h t i d e s i s a t night i n s p r i n g and summer. Each
month, t h e s e h i g h e r t i d e s r e a c h t h e i r peak a t t h e f u l l and new moon. C a l i f o r n i a g r u n i o n spawn e v e r y 4 weeks during t h e f u l l moon t i d a l s e r i e s (Thompson 1919). A p p a r e n t l y an i n d i v i d u a l g r u n i o n may spawn a b o u t e v e r y 2 weeks d u r i n g b o t h t h e f u l l and new moon c y c l e s . Female g r u n i o n a r e known t o spawn as many as e i g h t t i m e s a season on consecutive runs (Clark 1925). G r u n i o n b e g i n spawning t w o t o s i x n i g h t s a f t e r t h e peak t i d e s o f each c y c l e , when each s u c c e e d i n g t i d e i s lower than t h a t o f t h e previous n i g h t (Thompson 1919). O n l y t h r e e o r ' f o u r n i g h t s a r e s u i t a b l e f o r spawning d u r i n g each c y c l e . The spawning r u n s begin immediately a f t e r h i g h t i d e . At f i r s t , s e v e r a l f i s h , n o r m a l l y males, a r e swept up t h e beach and become t e m p o r a r i l y s t r a n d e d on t h e sand as t h e y swim a g a i n s t t h e r e c e d i n g w a t e r . G r a d u a l l y i n c r e a s i n g numbers o f b o t h sexes beach themselves w i t h s u c c e e d i n g waves. Spawning begins about 20 m i n u t e s a f t e r t h e f i r s t f i s h appear, peaks i n one hour, and l a s t s 30 t o 6 0 minutes. During peak spawning, thousands o f g r u n i o n 1 i t t e r t h e beach (Walker 1952). When t h e t i d e has ebbed about one f o o t , t h e n i g h t ' s r u n t e r m i n a t e s as s u d d e n l y as i t began. are accomT y p i c a l ly, females pan i e d b y one o r more males as t h e y swim t o w a r d shore (Walker 1952). U s i n g a beach seine, Thompson ( 1 9 1 9 ) c a p t u r e d t w i c e as many males as f e m a l e s d u r i n g a spawning r u n . If males a r e n o t p r e s e n t when t h e f e m a l e i s r e a d y t o spawn, she r e t u r n s t o t h e sea w i t h o u t l a y i n g eggs ( W a l k e r 1952). D u r i n g spawning, t h e f e m a l e a r c h e s h e r body, k e e p i n g t h e head up w h i l e t h e caudal f i n v i g o r o u s l y excavates t h e s e m i f l u i d sand ( W a l k e r 1952). As t h e t a i l s i n k s , t h e f e m a l e t w i s t s h e r body and d i g s t a i l f i r s t u n t i l she is b u r i e d up t o h e r p e c t o r a l f i n s . Occas i o n a l l y f e m a l e s c o m p l e t e l y b u r y thems e l v e s i n t h e n e s t (Thompson 1919). A f t e r t h e f e m a l e i s i n t h e n e s t , up t o e i g h t males a t t e m p t t o mate w i t h h e r ( W a l k e r 1952). The m a l e s c u r v e around
t h e female, p l a c i n g t h e i r v e n t s c l o s e to or i n c o n t a c t w i t h h e r body. C o n c u r r e n t l y , t h e female e m i t s eggs 50 t o 75 mm below t h e s u r f a c e o f t h e sand. The males d i s c h a r g e t h e i r m i l t i n t o t h e sand near t h e female and immedi a t e l y r e t r e a t toward t h e ocean. The m i l t f l o w s down t h e f e m a l e ' s body The u n t i l i t reaches t h e eggs below. female t h e n t w i s t s f r e e and r e t u r n s t o t h e sea w i t h t h e n e x t wave. Generally about 30 seconds e l a p s e f r o m " n e s t " d i g g i n g t o e g g l a y i n g b u t some f i s h remain on the beach f o r s e v e r a l minutes. Waves t e n d t o erode sand f r o m t h e beach as t h e t i d e r i s e s and t o d e p o s i t consequently, f a l l sand as i t f a l l s ; i n g t i d e s d e p o s i t more sand (41-46 cm) over p r e v i o u s l y b u r i e d eggs, which helps p r o t e c t t h e eggs d u r i n g low tides. The eggs remain i n t h e sand f o r a b o u t 10 days, u n t i l t h e h i g h e r t i d e o f t h e n e x t l u n a r s e r i e s erodes t h e sand and washes t h e eggs f r e e . Eggs do n o t h a t c h u n t i l t h e y are uncovered and a g i t a t e d b y t h e s u r f (Thompson 1919). Eggs of a s i n g l e c l u t c h hatch w i t h i n 2 t o 5 minutes. A g i t a t i o n i s necessary because 1a r v a l movement does n o t a i d i n escape f r o m t h e egg s h e l l . Seawater and a g i t a t i o n p r o b a b l y s t i m u l a t e t h e r e l e a s e o f an enzyme t h a t s o f t e n s t h e c o v e r i n g o f t h e egg (Daugherty 1962). A s t u d y by Thompson (1919) demonstrated t h a t egg capsules e f f e c t i v e l y p r o t e c t developing embryos from f r e s h w a t e r and d e s i c c a t i o n Eggs do n o t f o r a t l e a s t 8 days. u s u a l l y hatch prematurely unless t h e eggs a r e washed f r e e . For example, eggs l a i d on a calm n i g h t were washed f r e e t h e n e x t n i g h t by h i g h waves during a storm; the result was complete m o r t a l it y . Fecundity Fecundity i s p o s i t i v e l y correl a t e d w i t h t h e s i z e of t h e female. One female 137 mm l o n g ( a l l l e n g t h s are t o t a l l e n g t h s ) c o n t a i n e d 1,475 eggs and one 171 rnm l o n g had 2,528 (Thompson 1919). Six grunion nests
examined by Thompson (1919) c o n t a i n e d from 1,149 to 2,705 eggs (mean, 2,200). Counts o f 1,600 t o 3,600 eggs in eight females were made by 1a r g e r Daugherty (1962) ; i n s e v e r a l , females produced more eggs. Ova Development Ovar i e s of females col lected b e f o r e January c o n t a i n o n l y immature eggs (mode, 0.08 mm; l a r g e s t diameter, 0.27 rnm). I n January t h e eggs form an i n t e r m e d i a t e s i z e c l a s s which b y t h e end o f F e b r u a r y a t t a i n s a maximum d i a m e t e r o f 0.78 mm. F i s h taken i n F e b r u a r y w i t h l e s s f u l l y developed ova p r o b a b l y b e g i n spawning l a t e r i n t h e season. A m a t u r i n g egg s i z e c l a s s , 0.74 t o 1.29 mm, a r i s e s f r o m the intermediate class and i s u s u a l l y spawned i n March. I m m e d i a t e l y a f t e r the f i s h spawn, a second m a t u r i n g c l a s s o f eggs b e g i n s d i f f e r e n t i a t i n g and i s spawned 15 days l a t e r . T h i s 15-day c y c l e c o n t i n u e s t h r o u g h o u t t h e p e r i o d o f spawn ing; t h e r e f o r e , as t h e season progresses, a s l i g h t t i m e 1ag is e s t a b l ished between t h e 2-week t i d a l peaks and t h e spawning d a t e s ( C l a r k 1925). Throughout t h e spawning season t h e t h r e e egg s i z e c l a s s e s remain d i s t i n c t . As t h e number o f m a t u r i n g eggs d i f f e r e n t i a t e d from the intermediate c l a s s i n c r e a s e s d u r i n g t h e spawning season, immature eggs a r e p r o b a b l y r e c r u i t e d t o t h i s i n t e r m e d i a t e group. The number o f i n t e r m e d i a t e eggs i n each female decreases from one spawning t o t h e next. A f t e r t h e l a s t spawning, t h e r e m a i n i n g i n t e r m e d i a t e eggs a r e resorbed; t h e immature eggs are c a r r i e d over t o the next year ( C l a r k 1925). The spherical meter a t r a n g e of by M o f f a t t filaments atherinid depos it e d
C a l i f o r n i a g r u n i o n egg is and about 1.6 mm i n d i a A h a t c h i n g (David 1939). 1.75 t o 2.20 mm was r e p o r t e d (1977). The eggs l a c k t h e a t t a c h e d t o eggs o f many s p e c i e s ( C l a r k 1925). Newly eggs have many o i l g 1obu 1es
( D a v i d 1939). The s i z e and number v a r y d u r i n g development u n t i l o n l y one l a r g e u n c o l o r e d o i l g l o b u l e remains i n t h e y o l k sac of t h e l a r v a . Cleavage i s u s u a l l y c o m p l e t e 12 h o u r s a f t e r The . e m b r y o n i c a x i s i s f e r t i l ization. formed about 1 8 h o u r s a f t e r f e r t i l i z a t i o n , b u t t h e l e n s e s and a u d i t o r y caps u l e s do n o t f o r m u n t i l about 34 hours. The h e a r t b e g i n s b e a t i n g a t about 46 h o u r s and t h e head and t a i 1 a r e f r e e a t about 62 hours. B l o o d c i r c u l a t i o n can a l s o b e observed a t t h i s t i m e and t h e f o r m a t i o n o f t h e s o m i t e s i s n e a r l y complete. A t about 84 h o u r s t h e eyes o f t h e embryo a r e pigmented, t h e r e a r e two o t o l i t h s i n each a u d i t o r y c a p s u l e , t h e myomere c o u n t i s 45 o r more, and melanophores a r e p r e s e n t on t h e head, upper s i d e s , and above t h e gut. A t about 184 hours, t h e embryo has reached i t s f u l l l e n g t h , i t s p i g m e n t a t i o n i s complete, and i t i s ready t o hatch. I n one s t u d y , Thompson (1919), who c o l l e c t e d eggs f r o m a spawning beach d a i l y t o o b s e r v e development, r e p o r t e d t h a t most eggs h a t c h e d on t h e 1 0 t h day ( 2 4 0 h o u r s ) a f t e r spawning (and c o l l e c t i o n ) , 1 d a y before the next series o f high tides. The r e m a i n i n g eggs hatched on t h e n e x t day, showing t h a t t h e r a t e and d u r a t i o n of egg development i s i n s y n c h r o n y w i t h t h e t i d a l c y c l e . The e v o l u t i o n o f egg s i z e and y o l k volume i n g r u n i o n has a p p a r e n t l y been i n f l u e n c e d b y t h e t i d e s more t h a n b y t e m p e r a t u r e o r any other f a c t o r ( I Y o f f a t t and Thompson 1978b). Larval, Stages
P o s t 1a r v a l ,
and
Juvenile
I n contrast t o larvae of other marine fishes, C a l i f o r n i a grunion are 1a r g e and we1 1-developed when hatched. They are 6.5 t o 6.8 mm l o n g a t h a t c h i n g and 7.8 t o 8.0 mm l o n g a f t e r t h r e e days ( D a v i d 1939). A c c o r d i n g t o May (1971), t h e average l e n g t h o f 9 r e c e n t l y - h a t c h e d l a r v a e was 9.0 mm and t h a t o f 20 4-day o l d s was 9.4 mm. Newly-hatched grunion are extremely a c t i v e and t h e eyes and jaws are functional (Thompson 1919; May 1971).
The l a r v a e a r e c a p a b l e of immediate f e e d i n g b u t r e t a i n a y o l k sac f o r 4 t o 6 d a y s ( D a v i d 1939; May 1971). In l a b o r a t o r y f e e d i n g s t u d i e s , May (1971) showed t h a t g r u n i o n l a r v a e can l i v e f o r a r e l a t i v e l y long time without food -- some as l o n g as 3 weeks. In one e x p e r i m e n t , a l l l a r v a e t h a t s u r food began v ived 16 days w i t h o u t f e e d i n g when o f f e r e d f o o d and were a l i v e a t t h e end o f t h e s t u d y 2 0 days l a t e r (May 1971). Newly h a t c h e d l a r v a e u s u a l l y l i v e a t o r near t h e water s u r f a c e (David 1939). The mouth i s open t h e n , and t h e f i r s t buds o f t h e g i l l f i l a m e n t s a r e visible. L a r v a e do n o t b e g i n a c t i v e f e e d i n g u n t i l t h e second d a y a f t e r h a t c h i n g . Between t h e f i f t h and n i n t h day, swimming a c t i v i t y i n c r e a s e s and t h e y descend s l i g h t l y b e l o w t h e s u r f a c e f il m ( D a v i d 1939). The average l e n g t h o f 10 l a r v a e 16 days o l d was 1 2 . 2 mm, and t h a t o f 1 0 2 5 - d a y - o l d l a r v a e was 15.1 mm (May 1971). L a r v a l a t h e r i n i d s l i v e predomin a t e l y i n t h e neuston ( s u r f a c e ) l a y e r (Lindsay e t al. 1978); however, in collections from C a l i f o r n i a coastal w a t e r s , Kauffman e t a l . (1981) c o u l d n o t i d e n t i f y t o species t h e a t h e r i n i d l a r v a e l e s s t h a n 15 mm long. Most postlarval and juveni l e atherinids l o n g e r t h a n 15 mm were i d e n t i f i e d as grunion. L a r g e 1 a r v a e ( > I 5 mm) were captured e x c l u s i v e l y a t n i g h t u s i q g sampl i n g g e a r f i s h e d n e a r 5he s u r f a c e . Grunion T h e i r mean d e n s i t y was 10/m l a r v a e l o n g e r t h a n 15 mm were s c a r c e n e a r t h e s u r f a c e d u r i n g t h e d a y and a b s e n t a t m i d and b o t t o m d e p t h s d u r i n g day o r n i g h t . Grunion l a r v a e are strong swimmers and may simply a v o i d t h e sampl i n g g e a r d u r i n g t h e day. A c c o r d i n g t o Kauffman e t a l . (19811, a t h e r i n i d l a r v a e l o n g e r t h a n 1 0 mm accounted f o r more t h a n 90% o f t h e l a r v a e sampled g u r i n g t h e day A l l larvae ( d e n s i t y up t o 90/m c a u g h t a t m i d - d e p t h and n e a r - b o t t o m were l e s s t h a n 1 0 mm l o n g ( d e n s i t y 0. 5/m3). The p e r c e n t a g e i n c r e a s e o f the smaller larvae in mid-depth
.
.
samples t a k e n a t n i g h t i n d i c a t e s t h e y d i s p e r s e a t n i g h t (Kauffman e t a l . 1981). The young f i s h grow r a p i d l y and a r e about 127 mm l o n g a t t h e end o f t h e i r f i r s t y e a r o f l i f e (Walker 1952). Adults Except f o r spawning h a b i t s and behavior, l i t t l e i s known about t h e a d u l t stage i n the coastal zone. Grunion populations s e e m i n g l y move 1 i t t l e a l o n g t h e shore1 i n e (Walker 19521, b u t seasonal i n s h o r e - o f f s h o r e movements n o t a s s o c i a t e d w i t h spawning are well-documented. M a t u r i t y and L i f e Span G r u n i o n mature i n t h e i r second y e a r o f l i f e and have a s h o r t l i f e span. In January some yearl ing females c o n t a i n e d immature eggs, and o t h e r s i n t e r m e d i a t e - s i z e d eggs. In F e b r u a r y n e a r l y a l l young females had b o t h i m n a t u r e and i n t e r m e d i a t e eggs, and young males appeared t o be n e a r i n g maturity. They a p p a r e n t l y spawn i n t h e i r second y e a r o f l i f e (age group I ) . The l a r g e s t g r u n i o n c o l l e c t e d b y C l a r k (1925) was a 3 - y e a r - o l d male 170 mrn long. She c o l l e c t e d no g r u n i o n o l d e r t h a n age 11. GROWTH CHARACTERISTICS S c a l e s can be used t o s t u d y t h e age and g r o w t h o f g r u n i o n . I n cont r a s t t o many f i s h , g r u n i o n f o r m an annulus i n J u l y and August r a t h e r t h a n i n t h e s p r i n g ( C l a r k 1925). Growth d a t a g i v e n here, however, a r e based l a r g e l y on l e n g t h d i s t r i b u t i o n r a t h e r t h a n t h e s c a l e method. I n September, a t an age of about 2 months, average l e n g t h s were 79 mm f o r males and 8 1 mm f o r females. U n t i l September, t h e i r mean d a i l y g r o w t h r a t e was 0.73 mm ( C l a r k 1925). From September t o t h e end of January, t h e growth r a t e d e c l i n e d because o f low w i n t e r temperatures but accelerated again i n e a r l y February through A p r i l . I n September,
young-of-the-year females were only s l i g h t l y longer than young-of-the-year males, b u t b y A p r i l t h e f e m a l e s were about 10 mm l o n g e r . T h i s d i f f e r e n c e was m a i n t a i n e d t h r o u g h o u t a d u l t l i f e . The g r o w t h of age-groups I and I 1 a l s o a c c e l e r a t e d i n l a t e w i n t e r and s p r i n g , t h e n tended t o d e c l i n e i n e a r l y May w i t h l i t t l e growth e v i d e n t i n l a t e May, June and J u l y ( C l a r k 1925). Growth began a g a i n i n August. Growth o f g r u n i o n was most r a p i d d u r i n g t h e f i r s t y e a r o f 1 i f e and t h e n d e c l ined i n f o l l o w i n g y e a r s (Clark 1925). A t t h e end o f t h e f i r s t y e a r t h e mean t o t a l l e n g t h was about 110 mm f o r males and 119 mm f o r females. A f t e r t h e second y e a r ' s growth, average l e n g t h s were 129 and 140 mm. F o r t h e few f i s h r e a c h i n g t h e b e g i n n i n g o f a second spawning season, t h e average l e n g t h s were 143 mm ( m a l e s ) and 154 mm (females). The 1a r g e s t f i s h r e p o r t e d was 191 mm l o n g ( M i l l e r and Lea 1972). Among spawning f i s h caught i n a beach s e i n e i n A p r i l , average l e n g t h s o f males and females were 129.5 and 142.5 mm (Thompson 1919). According t o C l a r k ' s (1925) f i n d i n g s , t h e f i s h measured b y Thompson (1919) were p r o b a b l y e n t e r i n g t h e i r second spawning season. The r a t e o f w e i g h t g a i n was n o t as p r o p o r t i o n a t e l y r a p i d as t h e c o r responding increase i n l e n g t h d u r i n g the first y e a r ( C l a r k 1925). In f o l l o w i n g y e a r s , as g r o w t h i n l e n g t h slowed, t h e r a t e o f w e i g h t i n c r e a s e diminished o n l y s l i g h t l y . I n Februa r y , t h e mean w e i g h t o f y e a r l i n g f i s h was 11.8 grams f o r f i s h 110 mm l o n g , and 15.2 grams f o r f i s h 120 mm l o n g ( C l a r k 1925). F i s h i n age group I 1 and o l d e r , w h i c h were 130 t o 140 mm l o n g , averaged 19.3 t o 23.0 grams; and t h o s e 145 t o 155 l o n g averaged 26.7 t o 32.3 grams. C a l c u l a t e d w e i g h t s , based on the formula Weight (g)=0.0089 Length3 (mm) , d i f f e r e d o n l y s l i g h t l y f r o m t h e mean measured w e i g h t s .
COMMERCIAL AND SPORT FISHERIES Cal i f o r n i a g r u n i o n a r e sought by sportsmen, n a t u r e l o v e r s , and c u r i o u s observers dur ing grunion spawn i n g runs, y e t a c c u r a t e e s t i m a t e s o f t h e s p o r t c a t c h and t h e c o n t r i b u t i o n t o the economy are lacking. Despite t h e i r h i g h c o n c e n t r a t i o n on beaches during spawning, grunion are n o t A few a r e abundant (Walker 1952). landed c o m m e r c i a l l y b y round h a u l n e t s and lamparas and a r e s o l d f o r b a i t o r marketed as s m e l t i n t h e f r e s h - f i s h market (Clark 1928; Young 1949; Daugherty 1962; F r e y 1971). Most g r u n i o n landed c o m m e r c i a l l y a r e t a k e n i n l a t e w i n t e r and i n s p r i n g j u s t before t h e spawning season (Clark 1928). In February 1927 t h e Los Angeles County g r u n i o n c a t c h f o r t h e fresh-fish market peaked a t about 1b 6,000 1b and averaged about 2,759 m o n t h l y i n January-March. The h i g h e s t 1b from c a t c h r e p o r t e d was 9,573 October 1926 t o October 1927. No commercial l a n d i n g s o f g r u n i o n have been reported since ( F r e y 1971), p r o b a b l y because they are caught largely by smelt fishermen and r e p o r t e d i n t h e s m e l t catch. Grunion are o c c a s i o n a l l y t a k e n i n p u r e h a u l s o f up t o 4 o r 5 t o n s (Daugherty 1962). Only t h e n a r e g r u n i o n s o l d as f r e s h smelt are f i s h and then o n l y i f relatively scarce. Otherwise, t h e mixed c a t c h i s s o l d as b a i t o r t o canners of p e t food (Daugherty 1962). I n the 1920's the grunion f i s h e r y began showing signs o f depletion ( C l a r k 1928), which was p r o b a b l y due t o o v e r f i s h i n g and h a b i t a t a l t e r a t i o n (Walker 1952). From 1927 t o 1946, t h e fishing season in C a l i f o r n i a was By 1947, c l o s e d f r o m A p r i l t o June. abundance had increased and the r e s t r i c t i o n was eased. Grunion may now be taken by sportsmen o n l y b y hand t h r o u g h o u t t h e y e a r except i n A p r i l and May. Although t h e p o p u l a t i o n s i z e i s unknown, t h e r e s o u r c e appears t o be m a i n t a i n i n g i t s e l f under t h e p r e s e n t Klingbeil, s p o r t f i s h i n g i n t e n s i t y (R. Cal i f o r n i a Department o f F i s h and
1983). Since Game; pers. comm., grunion populations seldom move l a t e r a l l y a l o n g t h e shore1 ine, l o c a l c o n t r o l s may be adequate f o r management (Walker 1952).
ECOLOGICAL ROLE I n s p i t e o f the p u b l i c i t y given t o t h e unique spawning b e h a v i o r o f t h e grunion, l i t t l e a t t e n t i o n has been given t o i t s ecological role. Gut c o n t e n t a n a l y s i s indicated t h a t grunion fed p r i m a r i l y during the Food day (Kauffman e t a l . 1981). found i n l a r v a e l e s s than 10 mm l o n g c o n s i s t e d l a r g e l y o f copepod n a u p l i i and t i n t i n n i d protozoans. Cyclopoid copepods, O i t h o n a sp., numerically dominate t h e g u t c o n t e n t s o f l a r v a e lonq. The har~actacoid 10-28 mm copepod ~ u t e r ~ i n aa c u t i f r o n s and c v c l o ~ o i d c o ~ e o o d Corvcaeus the are much less ab;ndant e t a l . 1981). The r e l a t i v e l y low d e n s i t i e s o f these animals i n C a l i f o r n i a ' s c o a s t a l waters suggest t h a t most g r u n i o n l a r v a e must search f o r prey. 8
8
A d u l t g r u n i o n e a t food s i m i l a r t o t h a t e a t e n by l a r v a e and j u v e n i l e s . Stomach c o n t e n t s c o n s i s t e d o f m i c r o s c o p i c and s l i g h t l y l a r g e r p l a n k t o n i c organisms ( F i t c h and Lavenberg 1971). A l l l i f e stages o f g r u n i o n a r e preyed upon by a number of p r e d a t o r s . Eggs b u r i e d i n t h e beach sand a r e f e d upon by sand worms, shore b i r d s , and even ground squirrels (Fitch and (1949) Lavenberg 1971). Walker reported t h a t shorebirds, including marbled godwit (Limosa fedoa) and wh imbrel (Numenius p h a e o p u s ) t i v e l y probe t h e sand i n search of g r u n i o n eggs. An isopod, two species of f l i e s , and a b e e t l e a l s o preyed on b u r i e d g r u n i o n eggs ( F r e y 1971). Juven i l e and a d u l t a r u n i o n a r e Dreved uDon by ha1 i b u t ( p a r a 1 i c h t h y s ' c a i i f o r n i cus). sand bass ( P a r a l a b r a x ) . w h i t e
c r o a k e r s (Genyonemus 1 i n e a t u s ) , and o t h e r 1a r q.,e .~ r e d a t o r s i n c l u d i n .q, man ( F i t c h and Lavenberg 1971).
ENVIRONMENTAL REQUIREMENTS
hatched. Lower and upper l e t h a l s a l in i t i e s f o r p r o l a r v a e were 4.2 and 4 1 p p t and f o r 20-day-old post larvae t h e s e s a l i n i t i e s were, r e s p e c t i v e l y , 9 and 30 p p t (Reynolds e t a l . 1976). A decrease i n s a l i n i t y t o l e r a ~ i c e w i t h age was a l s o r e p o r t e d .
T i d a l Cycle
Light
T i d a l c y c l e s may have i n f l u e n c e d the e v o l u t i o n o f egg s i z e i n t h e grunion. I n p o s s i b l e response t o t h e more i r r e g u l a r t i d e s o f Cal i f o r n i a , t h e eggs o f t h e Cal i f o r n i a g r u n i o n a r e much larger than those o f t h e i r closest congener Leuresthes sardina from the Gulf o f C a l i f o r n i a (Moffatt and Thompson 1978b).
Exposure t o l i g h t seems t o r e d u c e hatching success of g r u n i o n eggs (Hubbs 1965). Young g r u n i o n a r e p o s i t i v e l y p h o t o t a c t i c and can be a t t r a c t ed t o 1 i g h t as b r i g h t as 10,000 l u x (Reynolds e t a l . 1977). The s t r e n g t h o f t h e g a t h e r i n g r e s p o n s e i s appare n t l y related t o the strength o f the l i g h t stimulus.
C y c l i c t i d e s a l s o deposit addit i o n a l sand o v e r t h e d e v e l o p i n g eggs. T h i s provides p r o t e c t i o n from thermal, osmot ic, and d e s i c c a t i o n s t r e s s e s as w e l l as p r e d a t i o n (Middaugh e t a l . 1983).
Other Environmental Factors G r u n i o n eggs r e q u i r e m o i s t u r e t o prevent desiccation. Interstitial w a t e r ( g w a t e r / k g sand) i n g r u n i o n nests can range f r o m 1% t o 19% (Middaugh e t a l . 1983).
Temperature G r u n i o n eggs h a t c h o t e r a w a t e r t e m p e r a t u r e r a n g e o f 14.0 t o 28.5 OC. Water t e m p e r a t u r e s o f 29.8 OC and above r e d u c e d t h e v i a b i l i t y o f g r u n i o n l a r v a e (Hubbs 1965; E h r l i c h and F g r r i s 1971). An i n c r e a s e o f about 9 C i s r e q u i r e d t o double t h e development r a t e (Hubbs 1965). Yolk-sac l a r v a e showed a p r e f e r e n h e f o r w a t e r temperaC ( E h r l i c h and Must u r e s n e a r 25 z y n s k i 1981), w e l l above t h e r a n g e t h a t produced maximum growth. F e e d i n g larvae apparently select r e 1a t i v e l y h i g h t e m p e r a t u r e s f o r growth. The a b i 1i t y o f l a r v a e t o m e t a b ~ l i z e ~ f o o d( p r o t e i n J decreased above 25 C and b e l o w C ( f a t ) ( E h r l i c h and Muszynski 16 1981). Growth r a t e s a r e p o s i t i v e 1 c o r r e l a t e d w i t h t e m p e r a t u r e between 1 8 and 25.4 C ( E h r l i c h and F a r r i s 1972).
An un i d e n t i f i e d n o n t h e r m a l comp o n e n t o f power p l a n t e f f l u e n t s s i g n i f i c a n t l y r e d u c e s h a t c h i n g success o f g r u n i o n ( E h r l i c h 1977). At a l l t e s t t e m p e r a t u r e s t h e p e r c e n t a g e o f eggs h a t c h e d i n e f f l u e n t w a t e r was l o w e r t h a n t h e p e r c e n t a g e h a t c h e d i n sea w a t e r c o l l e c t e d b e f o r e passage t h r o u g h t h e power p l a n t . benzoExposure of eggs to ( a ) p y r e n e l e v e l s o f 24 ppb o r more decreased hatching percentage and increased morphological anomal i e s ( W i n k l e r e t a l . 1983).
(Y
T h e r e i s no p u b l i s h e d i n f o r m a t i o n on dissolved oxygen or turbidity requirements for the Cal i f o r n i a grunion.
O n l y h a l f o f t h e g r u n i o n eggs p l a c e d i n f r e s h w a t e r b y Hubbs (1965)
The g r u n i o n i s the host of several c r u s t acean s and d ig e n e t i c trematodes. The s i x known c r u s t a c e a n p a r a s i t e s a r e t h e copepods Bomolachus Cal i g u s olsoni , and p e c t inatus, Clauel l o p s i s ; t h e r a c h i Argulus
Salinity
melanost i c t u s ; and the isopods Nerocila californica and Lironeca c a l i f o r n i c a (Olson 1972). Metacercariae w i t h t h e c h a r a c t e r i s t i c s of Bucephalopsis lebiatus (Trematoda: Bucephalidae) i n f e c t t h e g r u n i o n h e a r t muscle (Olson 1975). Among t h e trema-
todes, Asymphylodora a t h e r i nops i d i s occurs i n the p o s t e r i o r i n t e s t i n e o f t h e g r u n i o n w h i l e Lepocredium m a n t e r i occurs in the expanded anterior i n t e s t i n e (Olson 1977, 1978). The e f f e c t s of t h e s e p a r a s i t e s on growth and s u r v i v a l are n o t known.
LITERATURE CITED C l a r k , F. N. 1925. The l i f e h i s t o r y of Leuresthes tenuis, an atherine f i s h with cont r o l l e d spawning h a b i t s . Cal if. D i v . F i s h Game F i s h . B u l l . 10: 5 1 PP. C l a r k , F. N. 1928. The s m e l t s o f t h e San Pedro w h o l e s a l e f i s h markets. Cal i f . F i s h Game 14:16-21. Daugherty, A. E. 1962. California g r u n i o n , L e u r e s t h e s t e n u i s . Pages 29-30 i n C a l i f o r n i a ocean f i s h e r i e s r e s o u r c e s t o t h e y e a r 1960. Cal i f . Dep. F i s h Game, Sacramento. 79 PP. David, L. R. 1939. Embryonic and early larval stases of the grun-ion, ~euresthes tenuis, and o f t h e s c u l o i n . Scoroaena g u t t a t a . Copeia 1939:-75-81.' E h r l i c h , K. F. 1977. Inhibited h a t c h i n g success o f m a r i n e f i s h eggs b y power p l a n t effluent. Mar. P o l l u t . B u l l . 8(10):228-229. E h r l i c h , K. F., and D. A. F a r r i s . 1971. Some i n f l u e n c e s o f tempera t u r e on t h e develooment o f t h e grunion ~euresthes t e n u is ( A y r e s ) . C a l i f . F i s h Game V(TjT E h r l i c h , K. F., and D. A. F a r r i s . 1972. Some i n f l u e n c e s o f tempera t u r e on t h e r e a r i n g of the grunion, Leuresthes tenuis, an a t h e r i n e f i s h . Mar. Biol. ( B e r l . ) 12(4):267-271. E h r l i c h , K. F. and G. Muszynski. 1981. The relationship between
temperature-specific yolk u t i l i z a t i o n and t e m p e r a t u r e s e l e c t i o n o f l a r v a l grunion. I n L a s k e r and Sherman, eds. second- ICES Sympos i u m on t h e E a r l y L i f e H i s t o r y o f F i s h : r e c e n t s t u d i e s , Woods H o l e , 1979. Rapp. MA (USA) 2 Apr. P.-V. Reun. Cons. I n t . E x p l o r . Mer 178: 312-313. Eschmeyer, W. Hammann. Pacific America t o Baja Mifflin,
N.,
E. S. H e r a l d , and H. 1983. A f i e l d g u i d e t o coast fishes o f North from the G u l f o f Alaska Cal i f o r n i a. Houghton Boston. 336 pp.
and R. J. Lavenberg. F i t c h , J. E., 1971. Marine food and game fishes of California. IJniv. C a l i f . Press, B e r k e l e y . 179 pp. Frey, H. W., ed. 1971. California's 1 i v i n g m a r i n e r e s o u r c e s and t h e i r C a l i f . Dep. Fish u t i l ization. Game. 148 pp. 1965. Developmental temHubbs, C. p e r a t u r e t o l e r a n c e and r a t e s o f f o u r southern C a l i f o r n i a fishes, Fundulus p a r v i p i n n i s , A t h e r i n o p s affinis, Leuresthes t e n u i s , and Hypsoblennius sp. Calif. Fish Game 5 1 ( 2 ) :113-122. Jordan, D. S., and B. W. Evermann. 1896. The f i s h e s o f N o r t h and M i d d l e America. U.S. N a t l . Mus. B u l l . 47: 4 v o l s . Kauffman, T. A., J. L i n d s a y , and R. Leithiser. 1981. Vertical d ist r i b u t i o n and f o o d s e l e c t i o n o f larval a t h e r i n ids. Pages 342343 i n L a s k e r and Sherman, eds.
2nd ICES Symposium on t h e E a r l y L i f e H i s t o r y o f Fish: Recent S t u d i e s , Woods Hole, MA, USA, 2-5 Apr. 1979. Rapp. P.-V. Reun. Cons. I n t . E x p l o r . Mer, Vol. 178. L i n d s a y , J. A,, E. R. Radle, and J. C. S. Wang. 1978. A supplemental sampl i n g method for estuarine i c h t h y o p l a n k t o n w i t h emphasis on Ather inidae. Estuaries l(1): 60-64. May, R. C. 1971. E f f e c t s o f d e l a y e d i n i t i a l f e e d i n g on l a r v a e o f t h e g r u n ion, Leuresthes tenuis (Ayres). U.S. N a t l . Mar.Serv. F i s h . B u l l . 69(2):411-425. Middaugh, D. P., H. W. Kohl, and L. E. Burnet. 1983. C o n c u r r e n t measurement o f i n t e r t i d a l e n v i r o n m e n t a l v a r i a b l e s and embryo s u r v i v a l f o r t h e C a l i f o r n i a grunion, Leuresthes tenuis, and A t 1 a n t i c silversides, Menidia menidia (Pisces: Atherinidae). Calif. F i s h Game 69(2):89-96. M i l l e r , D. J . , and R. N. Lea. 1972. Guide to the coastal marine fishes o f California. Calif. Dep. F i s h Game F i s h B u l l . 157. 249 pp. M o f f a t t , N. M. 1977. The e v o l u t i o n o f beach spawning i n t h e g r u n i o n (Leuresthes) : an hypothesis. C ~ ~ C O F I Conference, La 1977 J o l l a , C a l i f . (Abstr.) M o f f a t t , N. M., and D. A. Thompson. 1978a. Reciprocal hybridization between t h e C a l i f o r n i a and G u l f o f C a l i f o r n i a grunions, Leuresthes tenuis and L e u m s sardina-ther inidae). U.S. N a t l . Mar. F i s h . Serv. Fish. B u l l . 76(2):476-480. M o f f a t t , N. M., and D. A. Thompson. 1978b. T i d a l i n f l u e n c e on t h e e v o l u t i o n o f egg s i z e i n the grdn ions (Leuresthes, A t h e r i n i -
dae). Environ. 3(3):267-274.
Biol.
Fishes
Olson, A. C., Jr. 1972. Argulus m e l a n o s t i c t u s and o t h e r p a r a s i t i c c r u s t a c e a n s on t h e C a l i f o r n i a grunion, Leuresthes tenuis (Osteichthyes: A t h e r i n i d a e ) X P a r a s i t o l . 58(6):1201-1204. Olson, A. C., J r . 1975. Metacercaria of Bucephalopsis 1a b i a t u s (Trematoda: Bucephal i d a e ) in Cal i f o r n i a grunion, Leuresthes t e n u i s . J. P a r a s i t o l . 61(1):50. Olson, A. dora
C.,
Jr. 1977. a t h e r in iops id is tdda: M o n o r c h i i d a e ) California grunion, tenuis, including a tion. J. P a r a s i t o l . 298.
Asymphlo(Tremafrom the Leuresthes redescrip63(2):295-
Olson,A. C., Jr. 1978. Lepocreadium manteri sp. n. (Trematdda: L e p o c r e a d i i d a e ) f r o m t h e California grunion, Leuresthes tenuis, and i t s hyperparasit i c mlcrosporidian. Proc. H e l m i n t h o l . Soc. Wash. 45(2):155-157.
-
Reynolds, W. W., D. A. Thompson, and M. E. C a s t e r l i n . 1976. Temperat u r e and s a l i n i t y t o l e r a n c e s o f USA g r u n i o n larval Cal i f o r n i a Leuresthes tenuis, a compar ison with gulfgrunion Leuresthes sardina. J. Exp. Mar. BioT. E c o ~ . 24(1):73-82. Reynolds, W. W., D. A. Thompson, and M. E. C a s t e r 1 i n . 1977. Responses o f young C a l i f o r n i a g r u n i o n , Leuresthes tenuis, to g r a d ie n t s o f t e m p e r a t u r e and l i g h t . Copeia 1977(1):144-149. Spratt, J. D. 1971. The amazing grunion. C a l i f . Dep. F i s h Game. 6 PP. D. S p r a t t , J. g r u n ion,
1981. California Leuresthes tenuis,
spawn i n Monterey Bay, California. Calif. FishGame67(2): 134. 1913. The spawning Thompson, W. F. of the grunion (Leuresthes tenuis). Calif. Fish Game Comm. Fish. B u l l . 3:27 pp. Walker, 0 . W. 1949. Periodicity o f spawning by the grunion, atherLeuresthes tenuis, an ine fish. Ph,D. D i s s e r t a t i o n . University of Cal i f o r n i a , Los Angeles. 166 pp. Walker, 0 . W.
1952.
A
guide
to
the
grunion. 409-420.
C a l i f . F i s h Game 3 8 ( 3 ) :
W i n k l e r , D. L., K. L. Duncan, J. E. Hose, and H. W. Puffer. 1983. E f f e c t s o f benzo(a)pyrene on t h e e a r l y development o f t h e Cal if o r n i a grunion, L e u r e s t h e s t e n u i s (Pisces, Ather i n i d a e ) . U.S. N a t l . Mar. Fish. Serv. Fish. Bull. 8 1 ( 3 ) :473-481. Young, P. H. 1949. Live bait fishery. Pages 183-189 i n The commercial f i s h c a t c h o f C x i f o r n i a f o r t h e y e a r 1947 w i t h a h i s t o r i c a l r e v i e w 1916-1947. Cal if. Div. F i s h Game, F i s h . B u l l . 74. 267 pp.
SO272 -101
REPORT DOCUMENTATION PAGE 4
r l t l e e n d s u b ~ l t l = Species P r o f i l e s : L i f e H i s t o r i e s and Environmental Requirements o f Coastal Fishes and I n v e r t e b r a t e s ( P a c i f i c South-. west) -- C a l i f o r n i a Grunion
7. Author(%)
( 3.
3. Rsclp#ent's A c c e s s ~ o n N o
2.
i01 o a i c a l R e ~ o r t82(11.28) 5
February 1985 6 I
Ronald A . F r i tzsche, R o b e r t H. Chamberlain, and R o b e r t A. F i s h e r
8 . Pcrformnng O r g a n i l a t t o n Rept -
Performing Organizstion N a m e and Address
1 10. P r 0 , e c t l T a s k l W o r ~U n i t
NO
No
C a l i f o r n i a Cooperative F i s h e r y Research U n i t Humboldt S t a t e U n i v e r s i t y Arcata, CA 95521
13. Type o f R e p a d 6 Period Covered
12. Sponsoring O r 8 n i r a t i o n N a m e a n d Address
N a t i o n a l Eoastal Ecosystems Team U.S. Army Corps of Engineers F i s h and W i l d l i f e S e r v i c e . Waterways Experiment S t a t i o n U.S. Department o f t h e I n t e r i o r P.O. Box 631 Washington, DC 20240 Vicksburg, MS 39180
14.
15. S u p p l e m e n t 8 r y N o t e s
16. Abstract
(Limit:
200 words)
Species p r o f i l e s a r e l i t e r a t u r e summaries o f t h e taxonomy, range, l i f e h i s t o r y , e n v i r o n mental requirements, and importance o f c o a s t a l a q u a t i c species. They a r e prepared t o a s s i s t i n environmental impact assessment. The C a l i f o r n i a g r u n i o n (Leuresthes t e n u i s ) has l i t t l e commercial importance b u t i s one o f t h e most p o p u l a r s p o r t f i s h a l o n g t h e beaches o f s o u t h e r n C a l i f o r n i a . C a l i f o r n i a g r u n i o n spawn on sand beaches about e v e r y 2 weeks (as many as e i g h t spawnings p e r female) d u r i n g f u l l and new moon h i g h t i d e c y c l e s . The spawning season b e g i n s i n February-March and may extend t o e a r l y September. The eggs h a t c h i n about 2 weeks. C a l i f o r n i a g r u n i o n mature a t a young age and have a l i f e span o f about 3 y e a r s . Larvae and a d u l t s p r e y on p l a n k t o n i c organisms, p r i m a r i l y copepods. Eggs a r e preyed upon by beach scavengers; a d u l t s a r e f o r a g e f o r l a r g e r p i s c i v o r e s . The C a l i f o r n i a g r u n i o n e x h i b i t s a wide t o l e r a n c e o f s a l i n i t y and temperature. They h o s t s e v e r a l c r u s t a c e a n and d i g e n e t i c trematode p a r a s i t e s .
17. D o c u m e n t Analysis
Fishes Growth Spawning
a. Oes:r8pIars
Feeding Sand beaches
b. Identifierr/%en.Ended
Terms
C a l i f o r n i a grunion Leuresthes t e n u i s S a l i n i t y requirements
H a b i t a t requi. rements Life history Envi r o n n e n t a l r e q u i rements
C. C O S A T I F l c l d l C r o u p
18. Availabol#ty S t a t e m e n t
19. Securoty Class IThls R e p a n )
Unclassified
Unl i m i t e d
I (See ANSI-239.18)
20. Sscurnty Class
(This
Pagel
:I.
N O 01 Pages
12 22. P r ~ c e
Unclassified O P T I O N A L FORM 272 (4-1 (Formerly NTIS-251 Dcpanment o l Commerce
REGION 1
REGION 2
REGION 3
Regional Director U.S. Fish and Wildlife Service Lloyd Five Hundred Building, Suite 1692 500 N.E. Multnornah Street Portland, Oregon 97232
Regional Director U.S. Fish and Wildlife Service P.O. Box 1306 Albuquerque, New Mexico 87 103
Regional Director U.S. Fish and Wildlife Service Federal Building, Fort Snelling Twin Cities, Minnesota 55 1 1 1
REGION 4
REGION 5
REGION 6
Regional Director U.S. Fish and Wildlife Service Richard B. Russell Building 75 Spring Street, S.W. Atlanta, Georgia 30303
Regional Director U.S. Fish and Wildlife Service One Gateway Center Newton Corner, Massachusetts 02158
Regional Director U.S. Fish and Wildlife Service P.O. Box 25486 Denver Federal Center Denver, Colorado 80225
REGION 7 Regional Director U.S. Fish and Wildlife Service 1011 E. Tudor Road Anchorage, Alaska 99503
DEPARTMENT OF THE INTERIOR U.S. FISH AID WILDLIFE SERVICE As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our,nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserving theenvironmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration.
