Sardines from the Waters in The Neighbourhood of Tôkyô. (I):Fishing Season, Size and Form of Sardines in the North-eastern Parts of the Bays of Sagami and Suruga
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In the Bays of Sagami and Suruga, the north-eastern parts, which are denoted by NE in the following lines for the brevity's sake, are most important for the sardine fishery. From the autumn of 1932 to the summer of 1934, continuous records of the daily local catch and those of the measurements of body-length and of body-weight of the fish caught in these regions were kindly submitted to the writer by various agencies in situ. From these records the following results can be derived. Fishing Season: -In both districts, Sardinia melanosticta T. & S. is fished in the first half of the year, especially in two periods, from late Jan. to early March and from late March to May, and, in NE Suruga Bay, still in Oct. and Nov., while Engraulis japonicus T. & S. are abundantly caught in both districts in the later half of the year. The catches of Etrumeus micropus T. & S. and of Spratelloides japonicus HOUTTUYN are very small in NE Sagami Bay, but not so small in NE Suruga Bay, being held almost throughout the whole year except winter. Larval fish of Sardinia melanosticta appear in March to May, while those of other species in summer and autumn. Averaged Body-length of Fish Groups: -The averaged body-length for each group, -l, of Sardinia melanosticta, in its two main fishing seasons, above stated, is greater than 15cm, while in Jan. and May, or just before and after the seasons, it is less, ranging from 11 to 14cm. -l of Engraulis japonicus in NE Sagami Bay varies from 5 to 11cm, being grouped clearly in two ranges, 5.5-6.5cm and 9-11cm, from Apr. to July. In NE Suruga Bay, it is greater than 10cm in the first half of the year, whereas varies widely in the later half. Maximum values appear in Jan. in both districts. In NE Suruga Bay, -l of Etrurneus micropus varies in so wide a range as from that of larvae to 24cm, and -l of Spratelloides japonicus is 8-9cm from May to July but is less than 7cm, including larval fish, from Aug. to Dec. Generally speaking, for all species, larger fish appear in both districts in the earlier half of the year, while smaller in the later. Engraulis japonicus, Etrumeus micropus and Spratelloides japonicus are more or less longer in the averaged body-length in NE Suruga Bay than in NE Sagami Bay. Averaged Fatness: -The weight-length factor f defined by f=w/l3×1000, where w is the bodyweight in g and l the body length in cm of individual is employed to express the fatness, and the average value of f for each group, -l, is considered. -l of Sardinia melanosticta becomes minimum in March, i. e. 8 in NE Sagami Bay and 9 in NE Suruga, Bay, though in the latter district the value is mingled among larger ones, such as 12. Then -lis increased to 12 in Sagami Bay in May and June, and to 12-13 in Suruga Bay in July and Sept., none being less than 10 after Apr. -l of Engraulis japonicus is small in March and Apr., i.e. 8-9 in NE Sagami Bay and also less than 10 in NE Suruga Bay. It becomes 11 in Sagami Bay from June to Jan., though extraordinarily small values, such as 6, are sometimes found in the fall, while in Suruga Bay, in the later half of the year, it is sometimes large, such as 11.8 in July, and sometimes small, such as 8.3 in Oct. -l of Etrumeus micropus in NE Suruga Bay is very great, being 15.2 in late Nov., and thence is diminished in Dec. and Jan. attaining 11-12 from Apr. to June. For the occasional groups found in NE Sagami Bay, -l is 10-12.
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- Sardines from the Waters in The Neighbourhood of Tôkyô. (I):Fishing Season, Size and Form of Sardines in the North-eastern Parts of the Bays of Sagami and Suruga