瀬戸内海におけるウマヅラハギNavodon modestusの成長について

瀬戸内海におけるウマヅラハギの成長を明らかにするために,瀬戸内海の中部,西部および豊後水道で1964,'65年と'72-'76年の7年間に採集された24標本,雌雄それぞれ2,353尾を測定して雌雄別に各標本の体長組成を求め,次の結果を得た。
1) 雌雄共に発生後4箇月を経た発生年の10月には体長は13cmに,そして5箇月を経た11月には15cmに達し,発生年内における成長はそれ以降に比較して速い。
2) 雌の体長は平均して満1年で18cmに,満2年で22cmに,そして満3年では25cmに達する。
3) 雄の体長は平均して満1年で18cmに,満2年で22cmに,そして満3年では26cmに達する。
4) 体長(SL)と全長(TL)との関係は次式で表わされる。
雌; TL=1.16SL+0.94
雄; TL=1.13SL+1.35

The present paper aims to clarify the growth of the file-fish, Navodon modestus (GÜNTHER), inhabited in the Seto Inland Sea. The 24 samples with 4,706 individuals used for this study, were all immature and adult fishes collected from catches with a small set net, a trammel net or a small trawl in the years 1964, '65 and during an other period from 1972 to 1976 in the same Seto Inland Sea. After the standard length of each sample fish was measured, the sex of the immature fish was determined anatomically, but almost all of adult ones in spawning clusters, by its features. The general conclusions obtained from the length frequencies measurement can be summarized as follows:
1) Both male and female of under 1-year-old fish grow to 13 cm in October at the end of four months since hatch and to 15 cm in November at the end of five months in standard length at the average.
2) Both male and female of the adult fish measured 18 and 22 cm in standared length on an average at the full age of 1 and 2 years, respectively. Then a difference appeared: 3-years-old male grew up to 26 cm but the same 3-years-old female only to 25 cm in standared length.
3) The relationship between standard length (SL) and total length (TL) is linear, and can be expressed by the following equations:
Female; TL = 1.16 SL + 0.94
Male; TL = 1.13 SL + 1.35