Download influence of tides and waves on the spawning behavior of the gulf of

198
111114,ET N SOUTHERN CALIFORNIA ACADEMY OF SCIENCES VOLUME 75
Asso ins Vcrgicich zit einigen anderen Rodenfischen. Zeit. fur Tierpsychol.. 14:393-428.
Eesenius bicolor (Pisces, Teleostei, Blenniidae)
&it. fur Tierpsychol., 22:36-49,
. 1961. Uber dais Verhalten der Blenniiden
Runitla und Mph/op/tux (Pisces, Blenniidae). Zcit.
fur Tierpsychol.. 18:421-440.
1967. Specialization of organs having a
function in sonic marine fish. Stud. Trop.
Ocean:se., 5:539 5.48.
--.1963. Zum Problem der Signal bilthing.
am Beispiel der Verhaltenmimikry zwischen
Aspiihinrus und Labroides (Pisces. Acanthopterygii). Zeit. fur Tierpsychol., 20:657-679.
Wilson, D. P. 1969. Notes (loin the Plymouth
Aquarium. J. Mar. 1601, Assoc. U. K., 28:
. 1965. Zur Biologic 'Ind Ethologie von
345-351.
Accepted for publication May I. 1976.
INFLUENCE OF TIDES AND WAVES ON THE SPAWNING
BEHAVIOR OF THE GULF OF CALIFORNIA GRUNION,
LEURESTHES SARDINA (JENKINS AND EVERMANN)
DONALD A. THOMSON' AND KEVIN A. WENCH=
AnsrancT: A preliminary analysis of 53 spawning runs of the Gulf grunion, Leuresihes
sardina (Jenkins and Evermann) front 1968 to 1973 in the northern Gulf of California suggests
that the initiation of a spawning run is strongly dependent on tidal amplitude. Cuff grunion
i tins occur fortnightly front January to May following a descending series of higher high tides
after the new and full moon phases. The runs begin about 3.5 days after the time of full moon
and about four days after the new moon. The daytime runs of L. sardina result from a
mid-season shift in the time of the higher high spring titles front early morning (0300 to 0500)
to late afternoon (15(8)10 1700).
The accelerated spawning act of the Gulf grunion appears to be an adaptation to the short
period, low amplitude sea waves typical of the protected coasts of the upper Gulf of California
rather than increased daytime predation of spawning fish by sea birds.
Carl I_ Flubbs was the first to publish an account
of grunion spawning behavior when he reported a
fairly accurate description by J. P. Joplin from a
letter to David Starr Jordan (Huhhs, 1916). Much
later, one of Hubbs' graduate students (Walker,
1949) ditl the most thorough analysis of the spawning periodicity of the California grunion,
Leare.s.thes tennis (Ayres). As a tribute to Carl
Hobbs* longtime interest in the grunion, this paper
reports a preliminary analysis of the effect of tides
and waves on the spawning behavior and periodicity of another species of grunion, the Gulf of
California grunion. Learesthes sardina (Jenkins
and Evermann).
The only two species of grunion in the world
ocean. L. tennis and L. sardina. are geographically
isolated and morphologically distinct (Moffatt,
1974; Moffatt and Thomson, 1975). Both
species exhibit the unique behavior of spawning
out of water, depositing their eggs under the sand
of beaches following a high tide. Their spawning
runs are highly predictable and coincide with the
new and full moon phases which cause the fortnightly series of spring tides. The timing of the
runs of both species following a moon phase is
similar hut the California grunion is known to
spawn only at night whereas the Gulf grunion
spawns in the daytime as well as at night.
Spawning runs of L. tennis were believed by
'Dept. Ecology and Evolutionary Biology, Univ.
Arizona, Tucson, Arizona 85721.
=Southern California Edison Co., Rosemead,
California 91770.
1976
INFLUENCE OF TIDES AND WAVES ON GRUNION
earlier workers to be controlled by tides (Thompson, 1919: Clark, 1925). After analyzing numerous grunion runs, Walker (1949) hypothesized
that the timing of runs is set by the initiation of sex
product maturation at the second preceding moon
phase 17.9 days from the mid-point of a run series.
Walker's thorough study, although never published
in its entirely, led to successful predictions of California grunion runs (Walker, 1952). Since these
studies, nothing has been published on the periodicity of grunion runs. Our studies on the Gulf of
California grunion, L. sardina, began in 1968. We
have attempted to elucidate some of the factors influencing the periodicity of grunion runs by comparing runs of another species in a different tidal
and wave regime.
METHODS
Front 1968 to 1973, L. sardina runs were observed
along the beaches of El Golfo de Santa Clara,
Sonora, Mexico, in the northern Gulf of California. Data on 53 runs were compiled and timing
of each run was compared with the moon phase
and the time and height of the tides before, during
and after each run. [These data may be obtained
from the senior author upon request]. In many
instances, observers watched for runs prior to and
after a predicted run series to determine the number and intensity of runs in a series. All runs in a
series were used in the calculations of mean values.
Since tide information was unavailable for the El
Golfo de Santa Clara region, runs were compared
with tide predictions for Puerto Peiiasco, Sonora
(Thomson, 1968-73). Observations show that
the Puerto Petiasco tides are approximately synchronous with those of El Golfo although slightly
less in aniplitude.
Spawning behavior of Gulf grunion during night
and day runs was observed, filmed with 16 mm
and Super-8 mm cameras and compared with that
of the California grunion. The duration of the
spawning act and the period of sea waves washing
on the beach were timed with stopwatches.
TIDES AND GRUNION RUNS
Spawning runs of Gulf grunion occur from January through May, whereas California grunion
runs usually begin in early March and end in
August. Fortnightly Gulf grunion runs occur
consistently on the beaches in the vicinity of San
Felipe, Baja California Norte and El Golfo de
199
Figure 1. Night spawning of the Gulf grunion
(Leuresihes sardina) on the beach of El Golfo de
Santa Clara, Sonora, Mexico. Erect female in foreground is attended by five males. (Photo by D. A.
Thomson.)
Santa Clara, Sonora, Mexico, in the northern Gulf
of California. Spawning runs are also known to
occur on several suitable beaches south along both
coasts of the upper Gulf to Bahia Concepcion,
Baja California Sur and Guaymas, Sonora. However, such runs are sporadic and do not consistently occur following each new and full moon
phase. The occurrence of California grunion
runs are likewise less predictable in the northern
and southern margins of their range.
The most striking difference between the spawning runs of the two species of grunion is the dayti me run of the Gulf grunion. However, the
reason for this anomaly became clearer when the
pattern of spring tides during a grunion breeding
season was examined. The tides of the northern
Gulf of California are of the mixed semidiurnal
type. The higher high water occurs during early
morning (0300-0500) in January and February
which is the beginning of the Gulf grunion spawning season. Only night runs occur early in the season, closely following the early morning high tide.
During mid-season there is a shift in tidal amplitude so that the two daily high tides are about
equal. Daytime runs begin when the afternoon
high tide approaches the height of the night high
tide. When the afternoon high tide exceeds the
early morning high tide only daytime runs occur.
After comparing grunion runs with tide heights it
appeared that L. sardina was timing its run with
the higher high tide, regardless of when this tide
occurred. During the transition of the higher high
200
BULLETIN SOUTHERN CALIFORNIA ACADEMY OF SCIENCES
MARCH 1970
VOLUME 75
NIGHT a DAY RUNS
1976
INFLUENCE OF TIDES AND WAVES ON GRUNION
Maui I. Comparison of Gulf grunion runs following moon phases. Values include the mean (g) = one
standard deviation (s). N = total number of observations. P = probability from Student's t test.
NEW MOON
HHW max. after
moon phase (1970-73)•
APRIL 1970
DAY RUNS ONLY
-2
Fig,, v 2. Gulf grunion runs at El Got o showing trl nsi ion of highe high ti le to daytime and beginning of
daytime runs. Shaded area denotes darkness; clear areas denote daylight; numbers under tide curves mark the
number of high tit es after each moon phase. Tide curves are those predicted for Puerto Penasco, Sonora.
title from night to day, runs were often observed ing moon phase? L. sardina's runs show a mean
on successive high tides (Fig. 2). These successive 19.5 day interval after a full moon and 17.5 day
night and day runs occurred when the height dif- interval after a new moon. However, the midference between consecutive high tides was less point of a Gulf grunion run series occurs at about
than 0.5 m, indicating that the grunion were "com- 18.5 days after either moon phase, ranging from
paring" the height of each high tide during a run 17.4 to 19.8 days after the new and full moon.
series.
This duration closely agrees with Walker's (1949,
Walkers (1949) scheme of relating the timing 1952) egg maturation period of 17.9 days for
of runs to the moon phases involved predicting California grunion, based upon the mid-point of
runs beginning 2.5 days after a new moon and spawning runs.
4 days after a full moon. This permits a 17.9 day
The timing of the Gulf grunion's runs seems to
egg maturation period since it correlates with the be related to tide height rather than to moon phase
short and long intervals between new and full per se. During our period of observation of Gulf
moon (14 days) and full and new moon (15.5 grunion runs (January to May, 1968 to 1973)
days). The relationship of Gulf grunion runs to new moon tides were significantly higher than
the moon phases is nearly opposite to that pre- full moon tides, If grunion are selecting a tide
dicted by Walker for California grunion. After a height new moon runs might be expected to occur
full moon Gulf grunion runs start and reach their later after the moon phase than full moon runs.
peak earlier than runs following a new moon. Full Mean tide heights at the start and end of new and
moon runs usually begin 2.5 days to 3.5 days full moon grunion runs were quite similar, differafter the moon phase and new moon runs begin ing only by 0.21 and 0.11 m respectively (Table
3.5 to 4.5 days after the moon phase. The mean 1). Comparison of tide heights between night and
difference in days between new and full moon runs day runs showed no significant differences and
is about half a day or one high tide. Although provided even better agreement betwen the means
this difference is slight, it is highly consistent and of these tide level parameters (Table 2).
statistically significant ( P < 0.001; see Table I).
Therefore, it appears that the stimulus for
Does such a run sequence permit a uniform egg initiating a grunion run is a descending high tide
maturation period to be set by the second preced- of the proper tidal amplitude. Runs occurred at
201
No. of high tides
after moon phase at
start of each run
Days after moon phase
to high tide preceding
each run
Flt. of high tide
preceding each run
20
FULL MOON
5.34 m 0.28 m
(17.52 ft) (0.92 ft)
20
4.86 m 0.19 m
(15.94 ft) (0.62 ft)
<.001
27
8.15
1.43
26
6.92
1.29
<.01 > .001
27
4.06
0.70
26
3.36
0.64
<.001
27
26
Ht. of tide at start
of each run
3.67 m 0.53 m
(12.05 ft) (1.74 ft)
3.95 m 0.27 m
(12.95 ft) (0.90 ft)
22
3.56 m 0.56 m
(11.68 ft) (1.85 ft)
20
Ht. of tide at end
of each run
3.77 m 0.25 m
(12.36 ft) (0.81 ft)
21
<.05 > .02
<.1 > 05
2.97 m 0.45 m
<.5 > .4
(9.74 ft) (1.46 ft)
Duration of run ( min)
19
17
77.41
33.60
<.7 > .6
(1 hr 17.4 min)
• Maximum high tide heights from Estaci6n Puerto Palmer in Tablas de Prediccion de Marcus 1970 to 1973, Apendice I,
Part B, de ton Angles del Instituto de Geofisica, T.J.N.A.M. Vols. 15, 16, 17, and 18. Other tide heights taken from tide curves for
Puerto PeRasco (Thomson, 1968-1973).
2.86 m 0.37 m
(9.38 ft) (1.23 ft)
82.05
33.76
(1 hr 22.1 min)
extreme tide heights of -1- 4.4 to -1- 2.2 m, but much
more frequently at heights between -1- 4 and -1- 3.4
m. These data along with the switch from night to
day runs corresponding with the shift in the amplitude of the tides strongly suggest that L. sardina
is responding to tides directly rather than the moon
phase. This does not preclude the possibility that
egg and sperm maturation may have a lunar
rhythm, but it emphasizes that ripe grunion con-
17
sistently select a proper tide level for their spawning runs.
WAVES AND SPAWNING BEHAVIOR
The spawning behavior of L. sardina is very similar
to that of L. tennis but with one important exception. The duration of the spawning act (digging in
by the female, wrapping around the female's body
TABLE 2. Comparison of day and night Gulf grunion runs. Values include the mean (2 ) -± one standard
deviation (s). N = total number of grunion spawning runs observed. P = probability from Student's / test.
DAY
NIGHT
Days after moon phase
to high tide preceding
each run
Ht. of high tide 5
preceding each run
Ht. of tide at start
of each run
Ht. of tide at end
of each run
Duration of run (min)
28
3.67
0.88
25
3.78
0.58
3.82 m 0.31 m
(12.54 ft) (1.00 ft)
21
3.61 m 0.26 m
20
(11.83 ft) (0.84 ft)
2.86 m 0.34 m
18
20
(9.39 ft) (1.11 ft)
17
79.65
32.83
21
(I hr 19.7 mm)
All tide heights taken from predicted tide curves for Puerto Pefiasco (Thomson, 1968-73).
28
3.79 m 0.54 m
(12.45 ft) (1.78 ft)
3.73 m 0.59 m
(12.23 ft) (1.95 ft)
3.10 m 0.72 m
(10.18 ft) (2.35 ft)
34.11
82.52
(1 hr 22.5 min)
25
< .7 > .6
< .9 > .8
< .4 > .3
< .3 > .2
< .8 > .7
202
BULLETIN SOUTHERN CALIFORNIA ACADEMY OF SCIENCES VOLUME 75
by the male(s), extrusion of eggs and exit of female) proceeds much more rapidly in L. sardina.
The spawning act may last about 30 seconds in
L. tennis but only 3-7 seconds in L. sardina. The
most obvious suggestion Is that the faster spawning rate of L. sarditta is an adaptation to daytime
runs whereby the grunion is exposed to avian
predators. Numerous observations of sea bird
activity during daytime grunion runs indicate that
most predation of birds on grunion occurs while
the schools are moving in toward the beach. The
brown pelican (PeUranus ouldentalis) a cormorant (Phalacrocoras sp.) and several species of
sea gulls (Lartts delawarensis, L. atririlla, L. calljornicus, L. heermanni, and L. ocridentalis) have
been observed feeding on adult grunion close to
shore. Pelicans and cormorants feed on the
grunion only when the schools aggregate and swim
close to shore preceding a run. The sea gulls pick
grunion out of the surf and from the beach. However, sea gulls feed most actively at the beginning
of a run when the fish on the beach are mostly
scouts (males). By the time the run reaches its
peak and spawning is most intense very little
predation by sea gulls is observed. The birds
become satiated with grunion well before the peak
of the run and predation on spawning grunion is
minimal. After a run the egg pods are sought by
sanderlings ( Crocethia alba) and western sandpipers ( Erettnetes maw° and some egg predation
occurs. However, it seems unlikely that the accelerated spawning is primarily a defense adaptation
against avian predators.
An alternate hypothesis is that the spawning
rate is related to the waves carrying the fish up on
the beaches. The surf of the Pacific coast usually
has a longer period than the sea waves of the protected northern Gulf of California. Gayman
(19(s9) reported that sea breeze waves in the
northern Gulf in the vicinities of San Felipe and
F.1 Golfo generally have periods of 2-4 seconds.
The periods of waves timed with a stopwatch
during Gulf grunion runs ranged from 2.9 to 4
seconds. Gulf grunion are not carried up as high
on the beach by such waves as is typical of California grunion which ride the surf which strands
them at a considerable distance from the water
line. Gulf grunion, when interrupted by waves,
completed spawning within a maximum of 7 seconds but usually in 3-4 seconds. It was noted that
storm waves would sometimes prevent a run
altogether when a run was expected. Therefore, it
appears that the rapid spawning act of L. sardina
is at least partially an adaptation to the short
INFLUENCE OF TIDES AND WAVES ON GRUNION
1976
period, low amplitude waves of the Gulf of California.
manuscript and made useful suggestions. Logistics for
beginning phases of this study were supported by ONR
grant NR104-897.
DISCUSSION AND CONCLUSIONS
LITERATURE CITED
The switch from nighttime to daytime spawning
corresponds with the shift in the higher high tide
from night to day. This finding suggests that Gulf
grunion spawning runs are strongly influenced by
tidal amplitude. Such a shift in the daily higher
high tide does not occur on the Pacific coast.
Consequently, the California grunion spawns only
at night following the consistent Pacific coast pattern of the higher high tide occurring only at
night during the spawning season. Comparison of
the heights of the high tide preceding all runs and
the heights of the tide at the beginning, mid-point
and end of a run showed no statistical difference
between tide heights of night, day, new and full
moon spawning runs. However, it is not known
how the Gulf grunion is able to judge the proper
tidal height as the schools approach the beach.
The striking difference in spawning behavior
between L. sardina and L. lentils probably did not
evolve because of increased predation pressure on
daytime spawning grunion. We feel that it is more
likely that the accelerated spawning of L. sardina
is a response to the short period waves typical of
the northern Gulf of California beaches (there is
no difference in the duration of the spawning act
between daytime and nighttime runs). Unless the
eggs are fertilized and deposited in the sand very
quickly (within a few seconds) the spawning act
is apt to be interrupted by an oncoming wave and
any eggs laid would likely be washed out as well.
These short period, low amplitude waves do not
carry the grunion as far up on the beach as does
the longer period surf along the unprotected Pacific
coast, so spawning Gulf grunion are usually in
the wave wash zone not far from the surf.
Thus, the spawning behavior of the Gulf
grunion appears to be well adapted for tidal and
sea wave regimes of the upper Gulf of California.
Clark, F. N. 1925. The life history of Leuresthes
tennis, an atherinid fish with tide controlled
spawning habits. California Dept. Fish and
Game, Fish. Bull., 10:1-51.
Gayman, W. 1969. Waves and wave action. Pp.
56-71. In Environmental impact of brine effluents on Gulf of California. (D. A. Thomson, A.
R. Mead and J. F. Schreiber, eds.) Office Saline
Water Res. and Dev. Progr. Report, No. 387.
viii + 196 pp.
Hobbs, C. L. 1916. Notes on the marine fishes of
California. Univ. California Publ. Zool., 16:
153-169.
Moffatt, N. M. 1974. A morphometric and meristic
comparison of the Gulf grunion, Leuresthes
sardina (Jenkins and Evermann) and the Cali-
j
\ 11'
fornia grunion, Leuresthes tennis (Ayres). Masters thesis, Univ. Arizona. 36 pp.
Moffatt, N. M., and D. A. Thomson. 1975. Taxonomic status of the Gulf grunion, (Leuresthes
sardina) and its relationship to the California
grunion (L. tennis). Trans. San Diego Soc. Nat.
Hist., 18:75-84.
Thompson, W. F. 1919. The spawning of the
grunion, "Leuresthes I...... s." California Fish and
Game Comm., Fish Bull , 3:1-29.
Thomson, D. A. 1968-1973. Tide calendars for the
Northern Gulf of California. Bur. of Mimeogr.
and Multilith. Univ. Arizona.
Walker, B. W. 1949. Periodicity of spawning by
the grunion, Leuresthes tennis, an atherine fish.
Ph.D. thesis, Univ. California. 135 pp.
Walker, B. W. 1952. A guide to the grunion. California Fish and Game, 38:409-420.
Accepted for publication May 1, 1976.
.
A CONTRIBUTION TO THE LIFE HISTORY OF A
SMALL RATTAIL FISH, CORYPHAENOIDES CARAPINUS
RICHARD L. HAEDRICH AND PAMELA T. POLLONI I
Ansiancr: The North Atlantic macrourid Coryphaenoides (Lionurus) can apinus lives
between about 1200 and 2800 m off southern New England, with greatest abundance of about
2.4 individuals/1000 tn' in the transition zone from slope to rise. Larger individuals, mostly
female, tend to live at greater depths. Winter spawning is indicated, with 50,000 to 220,000
0.5-mm eggs being produced per female. Eighty-four of 108 stomachs examined contained
food. Benihic invertebrates were most important in the diet, and there was little change in
food with growth. The fish feeds selectively on the ophiuroid Ophiura ljungmani. The subgenera Nentatolturus. Chalinum, and Lionstrus of Coryphaenoides seem to occupy overlapping
yet distinct adaptive zones, with different prey and foraging area important considerations.
ACKNOWLEDGMENTS
We thank the numerous people who assisted us in
various ways during grunion spawning runs, especially
Chuck Constant and Ernie Kehl. We thank Boyd
Walker for accompanying us on two Gulf grunion
runs and appreciate his comments on comparisons
between the two species. We also thank Stephen
Russell for his identifications of sea birds. Charles
Lehner, Elaine Snyder and Nancy Moffatt read the
203
\
Despite the abundance and diversity of rattail
fishes in the deep ocean, remarkably little is known
concerning the natural history of any species, a
point emphasized by Marshall (1965) in a general
review of the biology of the group. Recent interest
and advances in deep bcnthic trawling have begun
to provide the material necessary for such work
(e.g., Podrazhanskaya, 1967; Pechenik and Troyanovski, 1970; Okamura, 1970; Novikov, 1970;
Geistdorfer, 1972, 1973; Pearcy and Ambler,
1974). Concerning the subgenus Lionurus of the
speciose and important genus Coryphaenoides, the
few published accounts are restricted almost entirely to distributional records. As a part of our
continuing studies of the ecology of deep ocean
' Woods Hole Oceanographic Institution, Woods
Hole, Massachusetts 02543.