CalCOFI Reports, Vol. 11, 1967 - California Cooperative Oceanic ...

REPORTS VOLUME XI, 1 JULY 1963 TO 30 JUNE 1966 49‘lripe” fish just before they discharge the ova orsperm in early summer (Usami and Sugiyama 1962).Abiotic Factors of the HabitatThe anchovy is regarded to be an eurythermal andeuryhaline species (Kubo 1961), because of the widespace-time extent of appearance of exploitable shoalsand spawning. The fish are easily transported acrossthe Kurosio Current alive in live-cars of fishingvessels even though no report was obtained from isolatedislands south of the current (Matsubara 1955,Hayasi 1961).Egg and larval stages. The eggs are found inareas, where surface temperatures range between 11and 29°C (Naki et al. 1955, Kubo 1961). Generallyspeaking, the surface temperature of the spawninggrounds is high in the southern area and low in thenorthern area (Table 3).--LocalitySouthern tip of Kyusyu _______________Surface temperature (“C)Range15-29Hyuganada east coast of Kyushu .______15-29Bungo Suido. east coast of Kyusyu----. 15-29Suho Nada, Seto Inland Sea ___________11-29Ise Bay, Pacific coast of Honsyu _______13-27Boso, Pacific coast of Honsyu __________14-27Amakusa Nada. west coast of Kyushu- - 16-27Wakasa Bay, Japan Sea _______________ 11-27Isikari Bay, Hokkaido ________________14-2311-15Okhotak coast of Hokkaido _ ___________-Majorspring season15-2515-2615-2915-2515-2616-1916-2114-2514-18--Chlorinity in areas where the anchovy eggs arefound range between 14.8 and 19.5 per mil, most frequently18.4-19.3 per mil (Nakai et al. 1955, Kubo2961). According to Nishikawa (1901), the eggs normallydevelop under a wide range of specific gravitybetween 1.012 and 1.033.The eggs occur most abundantly in the sea areaover the continental shelf and extending 10 milesmore offshore (Nakai et al. 1955, Kubo 1961). Mostof the eggs are distributed at a depth less than 301 mfrom the sea surface (Kubo 1961). Nishikawa (1901)recorded the eggs from the deeper layer between 45and 83 m. The larvae may live at almost the sameabiotic conditions with the eggs.Postlarval stage. Postlarval anchovies are widelydistributed from coast to offshore. Major fishinggrounds are located in areas with sand or mud bottom,under influence of river water.Juvenile through adult stages. Adults definitelyselect the open sea, while immature fish are distributedin bays and inlets as well as the open sea. The spawnersmay require abiotic conditions that differ fromthose of adults during the shoaling cycle.Although not defining which developmental stage,Eubo (1961) outlined the relationships between theanchovy, seemingly at the juvenile through adultstages, and abiotic factors as follows :“The anchovy is an eurythermal species, becausethe fish are caught throuzhout a year in some particularfishing grounds. Yanianaka and Ito (1957) estimatedthat the temperature of habitat ranges from 8to 30”C, through the field observation on catch andspawning. Suehiro (1936) determined the heat toleranceof the anchovy under rearing condition. Accordingto his experiment, it was found that 11’ and31” are the lowest and highest survivable rangesof the anchovy taken from the waters of 22-23°C.Compared with the sardine experimented under thesame time, it is found that optimum temperature ishigher for the anchovy than for the sardine. In thesame experiment, Suehiro (1936) determined that theanchovy died when the oxygen content of the waterdecreased to slightly less than 2 c.c./l. Distributiondepth is found to differ by time of a day, size or ageof fish, area, season and weather (Inoue and Ogura1958).Suehiro et al. (1957) reported that the anchovyare frightened by sounds of military cannons. Imamuraand Takeuchi (1960) found that the anchovyare attracted by light of 30-40 lux. through rearingexamination. ”Relation With Systematically or EcologicallyRelated FishesHayasi (1961) summarized the distribution of fishessystematically related with the Japanese anchovy asfollows :“The fishes of the genus Engraulis are widely distributedthroughout the temperate zones of the worldexcept for the Atlantic coast of North America, wherea closely related genus Anchoa occurs. Many of thesetwo genera have supported fisheries at various significancewithin the area in which they occur.In the temperate zone of the Far East, three othergenera of Stolephorinae are known to occur in additionto the genus Engraulis, and some of them werefairly important for the local fisheries in Korea. ”It is well known that in Japan the sardine andthe round herring have been ecologically and commerciallyrelated with the anchovy (Nakai et al. 1955,Yokota 1953, Ito 1961, Hayasi 1961). In addition, themackerels, Scomber japonicus Houttuyn and X. tapeinocephalusBleeker, and jack mackerel, Trachurusjaponicus (Temminck & Schlegel) , occupy almost thesame habitat as the anchovy (Yokota et al. 1961).Postlarval stage. Postlarval anchovy are oftencaught incidentally with postlarval sardine. The whitefish, Salangicthys microdon Bleeker, and postlarvaland juvenile sand lance, Ammodytes personatus Girard,are caught in more coastal area than the postlarvalanchovy. Postlarvae of a systematically relatedfish, Btolephorus zollingeri Bleeker? occur in the fish---=A recent paper has reported : “Records of Stolephomcs zollingerifrom Japanese waters (Hayashi and Tadokoro 1962) areclearly based on another Hawaiian enmaulid S. buccaneeriStrasburg (Whitehead, P. J. P., M. Bobsman, andA. C. Sheeler 1966. The types of Bleeker’s Indo-Pacificelopoid and clupeoid fishes, 2001. Verhand., Nat. Hist. Leiden,(84):159 PP).