한국산 민물 새우류에 관한 생물학적 연구 2. Palaemon modestua의 생태

BIOLOGICAL STUDIES ON THE FRESH-WATER SHRIMPS IN KOREA 2. The Ecology of Palaemon modestua

낙동강산 민물 새우, Palaemon modestua의 성장, 산란 및 성비등의 생태에 관해 조사한 결과는 아래와 같다. 1. 산란기간은 $4\~9$월 사이이며, 주 산란기는 7월이다. 2. 만 1년만에 생식 행위를 하며, 산란 후 10월 말경까지는 대부분 사멸하는 것 같다. 3. 성비 (수컷/암컷$\times$100)는 일평균 $78.5\%(44.2\~95.5\%)$이며, 4월과 9월에는 $44.2\%,\;44.9\%$로 하락하였다. 4. 포란 개체의 최소의 크기는 체장 29mm, 체중 0.5gr, 갑장 7mm 내외였다. 5. 포란 미수의 출현이 가장 많은 체장은 $31\~41mm$ 내외이었다. 6. 체장(X)과 난수(Y)의 회귀 관계식은 $$Y=0.0000203937X^{3.5668}$$이었다. 7. 체장(X)과 체중(Y)의 회귀 관계식은 $$female\;:\;Y=0.099801X^{2.85407}$$, $$male\;:\;Y=0.004198X^{3.40614}$$이었다. 8. 두흉 갑장(X)과 체중(Y)의 회귀 관계식은 $$female\;:\;Y=5.56008X^{2.25503}$$, $$male\;:\;Y=5.09541X^{2.28875}$$이었다. 9. 두흉 갑장(X)과 체장(Y)의 회귀 관계식은 female : Y=5.07540+3.36057X, male : Y=4.90514+3.47791X이었다.

The fresh_water shrimp, Palaemon modestua is one of the most important types of bait f[r fishing and can be found abundantly in the Nak-Dong River. The larval development of Palaemon modestua in the laboratory was reported by Liu (1949), Kown and Uno (1968), but they didn't give any ecological features in the natural environments. Shrimps were collected from the Nak-Dong River near Pusan, once a month from July to December 1953 and from February to June 1969 respectively. The following is a summary of the results: 1. They breed from April to September, mainly in July. 2. A generation of this type of shrimps appears to be approximately one year and after breeding they die off up untill the end of October. 3. The sex ratio (female=100) is $44.2\~95.5$ (mean 78.5) and goes down during spawning seasons. 4. The minimum size of the ovigerous female is approximately 0.5 gram in body weight, 29mm in body length and 7mm in carapace length. 5. Most shrimps of $31\~41mm$ In body length lay eggs. 6. The relationship between the boby length (X) and the number of eggs (Y) is: $$Y=0.0000203937X^{3.5668}$$ 7. The relationship between the body length (X) and the body weight (Y) is: $$Y=0.099801X^{2.85407}$$ in female. $$Y=0.004198X^{3.40614}$$ in Male. 8. The relationship between the carapace length (X) and the body weight (Y) is: $$Y=5.56008X^{2.25503}$$ in female. $$Y=5.09541X^{2.28875}$$ in male. 9. The relationship between the carapace length (X) and the body length (Y) is: Y= 5.07540+3.36057X in female. Y=4.90514+3.47791X in male.