The Common Occurrence of Oegopsid Squid Eggs in Near-Surface Oceanic Waters 1

Home , Brachioteuthidae, Myopsida, Oegopsida

RICHARD EDWARD YOUNG,2 ROBERT F. HARMAN,2 AND KATHARINA M. MANGOLD 3

ABSTRACT: A variety ofegg types removed from near-surface plankton tows off Hawaii developed into young squids. Previously, the eggs ofpelagic, oceanic squids were virtually unknown. Over 90% of these near-surface plankton tows taken with a l-m net contained squid eggs. About 90% ofthe eggs were collected in the upper 100m with most ofthese coming from the mixed layer. The eggs were separate rather than in masses. Two egg types have been identified. One belongs to the Enoploteuthinae, which are thought to spawn individual eggs. The other belongs to the Brachioteuthidae, whose spawning mode is unknown. Most squids are thought to deposit eggs in masses. Estimates, based on the abundance of the captured eggs, indicate that the chances of sampling an intact egg mass with a plankton net are small.

THE SPAWNED EGGS of marine animals can be Members of the Oegopsida are predomi useful guides for investigating life-history nantly oceanic species. Most of these squids strategies and adult population parameters, possess nidamental glands and, therefore, are and they can provide a source of young, un thought to produce egg masses. On several damaged animals for experimental purposes occasions oegopsid squids belonging to the (Price 1974; Stearns 1976; Stauffer and Pic Ommastrephidae have spawned in captivity quelle 1980). The eggs of pelagic, oceanic (Hamabe 1961, 1963; Boletzky et al. 1973; squids, however , are virtually unkown, even O'Dor et al. 1982). The eggs were generally though most species have larvae in near spawned in large masses (up to 100,000 eggs). surface waters. Very few records exist ofnaturally spawned Squids belong to the cephalopod order eggs or egg masses from oceanic cephalopods. Teuthoidea, which is divided into two sub Most of the early reports (d'Orbigny and Fe orders: Myopsida and Oegopsida. Members russac 1839; Collingwood 1873; Grenacher ofthe Myopsida (that is, the families Loligin 1874; Naef 1923 [Oegopsid X]; Sanzo 1929) idae and Pickfordiateuthidae) are almost ex described oegopsid egg masses of very simi clusively neritic in habitat. Members of the lar appearance: large, gelatinous, cylindrical most common myopsid genus, Loligo, deposit masses generally 60-90 em long by 10-20cm their eggs in many small masses on the shallow in diameter, containing rows of eggs which sea floor (McGowan 1954; Mangold-Wirz encircled the mass in a helix near its periphery. 1963; Waller and Wicklund 1968). During Sanzo (1929) attributed this type of egg mass spawning, the eggs are coated with a layer of to the large epipelagic squid Thysanoteuthis jelly from the oviducal glands which is, in rhombus after raising the eggs to hatching and turn, covered by large quantities ofjelly from comparing the hatchlings to identified larvae the nidamental glands (Jecklin 1934). taken from the plankton. In more recent years, this type ofegg mass has been observed at localities throughout much of the tropical

1 This material is based on research supported in part and temperate oceans of the world (Clarke by the National Science Foundation under Grant OCE 1966; Nesis 1975; Misaki and Okutani 1976; 82-07754. Manuscript accepted May 1985. Suzuki et al. 1979; pers. obs.) . Berrill (1966) 2 Department of Oceanography, University of Hawaii, 1000Pope Rd., Honolulu, HI 96822. published a beautiful color photograph ofone 3 Laboratorie Arago , F-66650 Banyuls-sur-Mer, ofthese egg masses which was misidentified as France . the pelagic tunicate Pyrosoma. 359 360 PACIFIC SCIENCE, Volume39, October 1985

Observations of other types of egg masses several occasions over the past 14 years, we have been few. Akimushkin (1963) reported have found large egg masses ofThysanoteuthis an unidentified, ribbonlike egg mass (70 x rhombus floating at the sea surface. We have 30 x 5 em) found "drifting at sea" south of not encountered any other egg masses despite Japan. Naef (1923) described embryos of an extensive trawling from the surface to depths ommastrephid from an egg mass found in the greater than 1000m using 3-m midwater Mediterranean Sea. Unfortunately, the egg trawls equipped with l-rn cod ends made of mass was not described. Jatta (1896) reported 333-JIm or 505-JIm mesh. Egg masses, there similar eggs from the Mediterranean. fore , have eluded us as they have eluded most The abovementioned egg masses were other researchers. The scarcity of records of sighted floating at the sea surface. A few re oegopsid eggs has been perplexing. Clarke ports exist ofoegopsid eggs that were taken in (1966) suggested that squids may spawn on nets . The number ofeggs taken in a single tow the continental slope at depths greater than was always rather low (generally between I 1000 m, where sampling is difficult. and 200), indicating that individual eggs, In November 1983, while examining near rather than egg masses , were being caught. surface plankton tows for squid larvae aboard Sasaki (1914) attributed such eggs from the the Japanese fishery training vessel Hokusei Sea of Japan to the enoploteuthid Watasenia Maru , we found an egg containing a well scintillans, which spawns in near-shore waters. developed squid embryo. On subsequent tows, Similar eggs have been reported from the Sea similar but undeveloped eggs were found. of Japan by Nishikawa (1906), Shimomura These eggs were placed in vials with filtered and Fukutaki (1957), Yamada (1937), and seawater that was frequently changed. All the Yamamoto (1943). These eggs generally were eggs developed into squid. Subsequent trawl found in near-surface waters, were ovoid in ing, reported in this paper, demonstrated that shape (approximately 1.5 x 1.2 mm) , and oegopsid eggs ofa variety ofspecies are abun were coated with jelly. Another type of egg dant in the near-surface plankton around found by Yamamoto (1946) and Okiyama Hawaii and are easily reared through hatching (1965) from the Sea ofJapan, and by Shojima and for several days after hatching. (1970, 1972) from the South China Sea, was also ovoidal and covered with jelly, but it was smaller (approximately 0.8-0.9 x 0.6 MATERIALS AND METHODS 0.8 mm). Although these eggs were originally thought to come from the ommastrephid Plankton tows were taken in Hawaiian Todarodes pacificus, Okiyama and Kasahara waters during a cruise from 16 November to (1975) concluded that the eggs were probably 3 December 1983 aboard the FTS Hokusei spawned by members of the Enoploteuthinae Maru and during five subsequent cruises other than W. scintillans. (19-22 December 1983, 9-12 March 1984, We are aware of only two other records of 6-15 April 1984, 8-11 August 1984, and net-caught eggs. Allan (1945), working off the 19-24 October 1984) aboard the RjV Kana eastern coast ofAustralia, found a single, un Keoki and the RfV Kila. Data on the vertical identified egg with a well-developed embryo, distribution of eggs were obtained from a and Nesis (1972,1973) found eight eggs in the series of stratified oblique tows to a depth of upper 300 m off the coast ofPeru and Ecuador 300 m with paired, opening-closing, 70-cm which he thought might belong to the enoplo bongo nets with 505-JIm mesh . Each tow was teuthid Abraliopsis affinis. The latter eggs designed to uniformly sample a 50-m depth were nearly spherical (1.l0 x 1.15mm) and stratum in the upper 200 m and a 109-m were coated with a sticky, buoyant, trans stratum from 200 to 300 m. Our only method parent jelly. ofdetermining the depth ofthe nets during the The waters around the Hawaiian Islands tow was a calcul ation based on wire angle and are occupied by 49 species ofoegopsid squids, wire out. A time-depth recorder attached to most ofwhich probably spawn in the area. On the nets gave an accurate record, after the tow , Squid Eggsin Oceanic Waters-e-Youxc, HARMAN, AND MANGOLD 361 of the actual depth fished. Forty-four tows except occasionally at the animal pole or at were successful, and our accuracy in placing the animal and vegetal poles; squid eggs are the nets at appropriate depths was adequate. usually ovoid whereas fish eggs are usually In the upper 150m, the strata sampled aver spherical; squid eggs are usually surrounded aged 43 m (SD = 7.2 m) in range and at by a sticky gelatinous layer or have a sticky depths over 150 m they averaged 80 m (SD = film (remnant of the gelatinous layer) on the 33 m) in range. Distributional data were com chorion whereas most fish eggs lack a gelati piled by apportioning the catch for each tow nous layer. (For a characterization of fish equally into 5-m depth increments. The catch eggs, see Ahlstrom and Moser 1980.) The rate for a given depth increment was taken large size, homogeneous appearance of the as the average for all rates at that depth. Sub yolk, and presence of a jelly layer distinguish sequently, the increments were combined into squid eggs from most free-floating crustacean 25-m depth zones . eggs. Ofthe first 59 plankton samples from the Oblique tows (75 or 150m to the surface) l-m net, 54 (92%) contained squid eggs. This for live eggs were taken with I-m nets of 505 high success rate has been approximately the }.lmmesh. These samples were sorted on board same on subsequent cruises, which have now ship using stereomicroscopes. Squid eggs re covered all seasons. moved from these samples were placed in The vertical distribution of the eggs is 0.045-}.lm filtered seawater within the wells of shown in Figure 2. The data indicate that tissue culture trays and were kept in an air about 90% of the eggs were in the upper conditioned room (22-24°C) with constant 100m, with 55% above 50m. Since the bot light. For identification purposes, photo tom of the mixed layer during this cruise was graphs of the eggs and embryos were taken at about 70 m (Figure 2), most of the eggs were every 6 hr, at which time the filtered seawater taken within this layer. Of the 17 tows with was changed. After hatching, the larvae were upper depth limits deeper than 100m, only transferred to i or I-liter bottles containing three captured eggs. One tow, however, cap 0.045-}.lm filtered seawater. The bottles were tured seven eggs between 150 and 200 m. The placed on rotators to prevent the young integrated catch through the water column squids from contacting the sides ofthe bottles. was 0.25 egg/m 2 of sea-surface area. This is Some of the larvae were given one or a com about half the abundance that was estimated bination ofthe following as a food source: (1) from oblique tows taken from 150-0m with mixed plankton, (2) rotifers, (3) copepods, (4) a l-m net during the December cruise (0.56 rotifers and/or copepods in combination with egg/rn"). three types of phytoplankters. During the April cruise, we attempted to raise 148 of the eggs captured. Of these, 81% survived to hatching. All larvae died by 7 days after hatching while kept at 22-24°C, pre RESULTS sumably due to starvation. At the time the Oegopsid eggs were found in a variety of eggs were removed from the plankton sample, shapes and sizes (see Figure 1)and colors . The approximately 90% were either involved in eggs found were always single rather than germ-layer formation or in the earliest stages clumped in a common layer ofjelly. Most of of organogenesis. These eggs, therefore, were the eggs were about the same size as most fish unrecognizable as cephalopods to the untrain eggs (usually about 1mm in diameter). Prior ed eye. A sample of 11developing embryos had to the appearance of distinctive embryos, a mean development time of 34 hr from cap however, squid eggs were easily distinguished ture, approximately Stage V of Naef (1923), from fish eggs in the following manner: fish to a stage where the embryos were easily recog eggs generally possess an oil globule whereas nized as squids (approximately Stage XIII squid eggs do not; fish eggs generally have a of Naef) at 22-24°C. The same embryos took noticeable perivitelline space whereas squid another 16 hr (average) before hatching. These eggs lack a detectable perivitelline space data are in general agreement with the relative 362 PACIFIC SCIENCE, Volume 39, October 1985

3b 4b

3d 4d

FIGURE I. Early life-history stages of oegopsid squids taken from near-surface plankton. Times indicate age since capture. Scale bar represents 0.5 mm. 1. Species I: a = I hr, b = 29 hr, c = 41 hr, d = 6 days. 2. Species 2: a = I hr, b = 20 hr, c = 39 hr, d = 6 days. 3. Species 3: a = I hr, b = 33 hr, c and d = 6 days. 4. Species 4: a = I hr, b = 41 hr, c = 59 hr, d = 3 days. rate ofdevelopment ofIllex illecebrosus raised XIII) to easily recognizable embryos (older in the laboratory (O'Dor et al. 1982), which than Stage XIII) of2 : 1to 3: 1, well below the indicate that the time spent in early develop 9 : I actually taken. During the rearing experi ment (up to Stage XIII) is about 66-75% of ments, premature hatching was often induced the total time to hatching. by trauma. Premature hatching in the trawls, Ifwe assume that the 16 hr from Stage XIII combined with natural mortality, presumably to hatching in the Hawaiian eggs represents is responsible for this discrepancy. At the time 25-34% of the total embryonic life, we can of hatching, the young squids possess a large estimate that the time from spawning to internal yolk supply and appear, on morpho hatching in these eggs was 2.0 to 2.7 days. logical grounds (no apparent mouth, suckers (Water temperature in the lab was 1-3°e without acetabulae, and so forth), to be incap cooler than the mixed layer.) The develop able of feeding. The squid hatchlings were ment rates also suggest a capture ratio of un easily raised until the internal yolk was fully recognizable embryos (younger than Stage absorbed. The feeding experiments, which Squid Eggs in Oceanic Waters-YoUNG, HARMAN, AND MANGOLD 363

NO. EGGS I 10.000 m3 and TEMPERATURE (OC) o 5 10 15 20 25 30

21.1 <0 r :t > ~ 100 -+----~------...... m ::xJ en > 3: 'lJ 200 ...m c E - 7 •• ... o -:z: • •0 (0) ... 300 11. :I W (0) C -

400

500

FIGURE 2. Vertical distribution of eggs in upper 300m; sampling effort; vertical temperature profile. Histograms (0-300 m) indicate number of eggs. Curve represents temperature. Egg abundance and temperature scales are identical. commenced two days after hatching, were Species 2 was distinguished by the relatively unsuccessful. We were unable to confirm that early appearance of very large pigmented any feeding occurred. areas . Species I embryos were distinguished Many of the eggs, embryos, and hatchlings by the relatively early development of the ink have distinctive features which should eventu sac. All of the hatchling types had distinctive ally allow identification at a very early stage. chromatophore patterns. We could identify Of the four species illustrated in Figure I, for two ofthe species reared. Our Species 3 hatch example, two had distinctive egg shapes (Spe ling, with its long neck and distinctive cies 3 and 4). One had a distinctive sculptured chromatophore pattern, could be matched chorion (Species 4). One had a distinctive with larvae taken from plankton tows. This green tint (Species 2). The early embryo of species is our common species of Bra Species 3 was distinguished by the weak devel chioteuthis. (The systematics of this genus are opment of the arms . The late embryo of confused and most species cannot be identi Species 4 was distinguished by its large num fied.) Our Species 4, with a distinctive sculp ber of chromatophores. The early embryo of tured chorion, could be identified as 364 PACIFIC SCIENCE, Volume 39, October 1985

Enoploteuthis reticulata. A large female ofthis Enoploteuthinae or it spawns fragile egg species in our collections carried these distinc masses that fragment shortly after spawning. tive eggs, whereas related species had unsculp The absence of eggs from the other com tured eggs. mon families suggests that these species are Although identification of other species laying eggs in masses. Abundance figures for must await the difficult process of tracing the the captured eggs provide a method for esti identity of captured specimens through a de mating the probability of capturing a pelagic creasing size series to the smallest larvae, we egg mass. Assuming that a squid, such as one can narrow the possibilities. The character of the smaller ommastrephids, produces an istics of the hatchlings do not match those of egg mass of 10,000 eggs (a small egg mass), many of the common larvae collected dur and that egg abundance in this population is ing our sampling periods. Among these were about the same as that ofthe eggs ofthe most larvae ofthe Onychoteuthidae, Ommastreph common species found in this study (about 3 idae, Ctenopterygidae, and the enoploteuthid 1.3 eggsjlOOOm , or approximately 10,000 subfamily Pyroteuthinae. The larvae from eggsj7,700,000m3 of water), and that the egg these groups comprised 60% ofall larvae cap masses are randomly distributed in the upper tured. The two types ofeggs identified belong 100m, then with a l-m net, which samples to species that were represented by 7% of the 1400m3 per tow, we would have only a 63% net-captured larvae. Another nine families , chance of capturing an egg mass with about representing 16 species, made up only 9% of 5500 net tows that sample the appropriate the net-captured larvae. The remaining 24% depth stratum. (About 5500 tows would be of the larvae belonged to the enoploteuthid needed to filter 7,700,000 m3.)4 This exercise subfamily Enoploteuthinae. We have tenta suggests that the chance of encountering an tively recognized between 7 and 11 species egg mass ofany appreciable size with a plank from the hatchlings obtained thus far. ton net is small. These odds are compounded by the fact that a captured egg mass may not have easily recognizable eggs. Therefore, the scarcity of reports of squid egg masses from DISCUSSION plankton tows is not surprising. Clearly, quantitative sampling is impractical if the eggs The eggs sampled represent only a portion remain in masses until hatching. Eggs laid of the species that were spawning during the individually or in fragile egg masses can be cruise periods. Judging from the relative easily sampled, and their availability opens abundance ofnet-captured larvae, most ofthe exciting new avenues ofresearch. unidentified eggs probably belong to the enoploteuthid subfamily Enoploteuthinae. Around Hawaii, there are eight species in this ACKNOWLEDGMENTS subfamily (two Abralia, three Abraliopsis, and We thank the officers and crews ofthe FTS three Enoploteuthis). Since we could be sam pling eggs ofas few as seven species, the num Hokusei Maru, the RjV Kana Keoki, and the bers are compatible with this hypothesis. RjV Kila for their help and cooperation and Members ofthis subfamily lack nidamental B. Burch for her assistance in sorting and glands and are thought to lay single pelagic raising eggs on one cruise. We also thank S. von Boletzky, T. Okutani, and C.F.E. Roper eggs (Okiyama and Kasahara 1975). One of our eggs, however, belongs to the family Bra chioteuthidae. Nidamental glands, which are "The probability of encounter is determined by terms responsible for egg mass formation, occur in in the expansion of (p + q)", where q is the probability of species ofthe Brachioteuthidae (M. Sweeney, not encountering an egg mass in a single tow (that is, 5499/5500), p is the probability of encountering an egg U.S. Mus. Nat. Hist., pers . comm.). Presum mass in a single tow, and n = 5500. The probability of ably , Brachioteuthis spp. either spawns single encountering an egg mass in 5500 tows is I _ q 55 0 0 eggs using a different mechanism than in the (Mendenha111971).

'at It exII 1, K) t, ne·i·ueeemljY'N!'KMttrennWiffl=tf& f lfMffilM Squid Eggs in Oceanic Waters-Yo UNG, HARMAN, ANDMANGOLD 365 for reviewing the manuscript and M. Pace for JECKLIN, L. 1934. Beitrag zur Kenntnis der advice on probabilit y determinations. Laichgallerten und Biologie der Em bryonen decapoder Cephalopoden. Rev. Suisse Zoo!' 41: 593-693. LITERATURE CITED MANGOLD-WIRZ, K. 1963. Biologie des Ce phalopodes benthiques et nectoniques de AHLSTROM, E. H., and H. G. MosER. 1980. la Mer Catalane. Vie Milieu 13 (supp!.): Characters useful in identification of 1-285. pelagic marine fish eggs. Rep. CalCOFI. MCGOWAN, J. A. 1954. Observation on the 21: 121- 131. sexual behavior and spawning of the squid AKIMUSHKIN, 1. 1. 1963. Cepalopods of the Loligo opalescens at La Jolla. Calif. Fish & seas of the U.S.S.R. [trans!. from Russian Game 40: 47-54. by A. Mercado] . Israel Prog. for Sci. MENDENHALL, W. 1971. Introduction to prob Trans!., Jerusalem. ability and statistics. 3rd ed. Duxbury, ALLAN, J. 1945.Planktonic cephalopod larvae Mass . from the eastern Australian coast. Rec. MISAKI, H., and T. OKUTANI. 1976. Studie s Austra!. Mu s. 21(6) :317- 350. on the early life histo ry of decapodan BERRILL, N. J. 1966. The life of the ocean. molluscs-VI. An evidence of spawning of McGraw-Hill, New York. an oceanic squid, Thysanoteuthis rhombus BOLETZKY, S. V., L. ROWE, and L. AROLES . Troschel, in Japanese waters. Jap. J. Malac. 1973. Spawning and the development of the 35(4) :2 11-213. eggs, in the laboratory, of !/lex coindetii NAEF, A. 1923. Die Ceph alopoden. Fauna (Mollusca: Cephalopoda). Veliger 15:257 Flora Golf. Neapel 35: 1-863. 258. NESIS, K. N. 1972. Oceanic cephalopods of the CLARKE, M. R. 1966. A review of the systema Peru Current: Horizontal and vertical dis tics and ecology of oceanic squids . Pages tribution. Okeano!' 12(3): 426-442. 91-300 in F. S. Russell, ed.,Advances in ---.1973. Cephalopods of the eastern marine biology. Vo!. 4. Academic Press, equatorial and southeastern Pacific Ocean. London. Trud. Inst. Okeano!' 94: 188-242. COLLINGWOOD, C. 1873. On a new form of ---.1975. Cephalopods of the American cephalopodous ova. J. Linn. Soc. Zoo!. Mediterranean Sea. Trud. Inst. Okeano!. II :90-94. 100:259-288. D'ORBIGNY, A., and A. FERUSSAC. 1839. His NISHIKAWA, T. 1906.On a pelagic cephalopod toire generale et particulaire des cephalo egg. Zoo!. Mag. Tokyo 18:310-314. podes acetabuliferes, vivantes et fossile. O'DoR , R. K., N. BALCH, E. A. Fov, R.W.M. Paris . HIRTLE, D. A. JOHNSTON, and T. AMARA GRENACHER, H. 1874. Zur Entwicklungsge TUNGA. 1982. Embryonic development of sichte der Cephalopoden. Z. Wiss. Zoo!' the squid, !/lex illecebrosus, and effect 24:419- 498. of temperature on development rates. J. HAMABE, M. 1961. Environmental studies Northw. At!. Fish. Sci. 3:41-45. on breeding habit and development of OKIYAMA, M. 1965. Some considerations on the squid, Ommastrephes sloani pacificus the eggs and larvae of the common squid Steenstrup, pt. II: Spawning behavior. Zoo!. Todarodes pacificus Steenstrup. Bull. Jap. Mag. Tokyo 70: 385- 394. Sea Reg. Fish. Res. Lab . 15:39-53. - - - .1963. Spawning experim ents of the OKIYAMA, M., and S. KASAHARA. 1975. common squid, Ommastrephes sloani pacif Identification of the so-called "common icus Steenstrup, in an indoor aquarium. squid eggs" collected in the Japan Sea and Bull. Jap. Soc. Sci. Fish . 29(10) :930-934. adjacent waters. Bul!. Jap. Sea Reg. Fish. JATTA, G . 1896. I cephalopodi viventi nel Res. Lab. 26: 35-40. Golfo Napoli (Sistematica). Fauna Flora PRICE, P. W. 1974. Strategies for egg produc Golf. Neapel 23: 1-268. tion. Evolution 28 :76-84. 366 PACIFIC SCIENCE, Volume 39, October 1985

SANZO, L. 1929. Nidamento pelagico, uova a A review of the ideas. Q. Rev. BioI. 51: larve di Thysanoteuthis rhombus Troschel. 3-47. Memorie R. Comm. talassogr. ital. 161: SUZUKI, S., H. MISAKI, and T. OKUTANI. 1979. 1-10. Studies on early life history of decapodan SASAKI, M. 1914. Observations on Hotaru-ika molluscs-VIII. A supplementary note on Watasenia scintillans. J. ColI. Agric. Toho floating egg mass of Thysanoteuthis rhom ku Imp. Univ. , Sapporo 4(4):75-107. bus Troschel in Japan-the first under SHIMOMURA, T., and H . FUKUTAKI. 1957. On water photography. Jap. J. Malac. 38(2) : the year-round occurrence and ecology of 153-155. eggs and larvae ofthe principal fishes in the WALLER, R. A., and R. I. WICKLUND. 1968. Japan Sea. Bull. Jap. Sea Reg. Fish. Res. Observations from a research submersible: Lab. 6 : 155-290. Mating and spawning of the squid Dory SHOJlMA, Y. 1970. Cephalopod larvae and teuthis plei. Biosci. 18: 110-111. eggs taken at the surface in the northern YAMADA, T. 1937. On the spawning of the South China Sea-I. Bull. Seikai Reg. Fish. squid, Watasenia scintillans, in the waters of Res. Lab. 38: 61-77. the east coast ofTyosen. Bull. Jap. Soc. Sci. ---.1972. The common squid, Todarodes Fish. 6(2): 75-78. pacificus, in the East China Sea-II. Bull. YAMAMOTO, T. 1943. Squids and octopus. Seikai Reg. Fish. Res. Lab. 42: 25-58. Kaiyo no Kagaku 3(10) [via Shimomura STAUFFER, G. D., and S. J. PICQUELLE. 1980. and Fukutaki 1957]. Estimate of the spawning biomass of the --- .1946. On the eggs and larvae of central subpopulation ofnorthern anchovy. Ommastrephes sloani pacificus collected SWFC Admin. Rep . LF-80-09. from Korean waters. Jap. J. Malac. STEARNS, S. C. 1976. Life history tactics: 14(4):228-240.