Post-embryonic development in Archaeomysis vulgaris (Nakazawa, 1910) reared in laboratory: Growth and sexual differentiation

Abstract

Aim: This study will help to understand the changes in survival rate and growth of juvenile A. vulgaris due to changing oceanic temperature. This study proved that water temperature among environmental factors affects A. vulgaris's developing period of secondary sexual characters, molting frequency, daily growth, and growth ratio of post-embryonic, especially in higher water temperature. Methodology: Archaeomysis vulgaris in South Korea were reared and analyzed under controlled condition of at 10, 18, 25 degrees C, ( 33-34 psu; 12/12 L/D) from hatching through a series of instars. Each specimen was individually maintained during the intermolt period, percentage increment and growth rate based on laboratory rearing. Result: This experiment result indicated the position of sexual molt variation related to water temperature followed by the statement of these species sexual characters appeared at 4th juvenile stage at 10 degrees C, 6th juvenile stage at 18 degrees C and 7th juvenile stage at 25 degrees C. Survival rates increased with temperature during the first juvenile stage to last molting stage. The growth rate of A. vulgaris at 10 degrees C, 18 degrees C and 25 degrees C was 0.05, 0.09 and 0.17 mm/daily. Intermolt period and the growth rate of mean carapace length were inversely correlated with temperature. The growth of carapace length between abdomen to telson to the other body parts of the A. vulgaris were significantly relative at 10 degrees C, 18 degrees C and 25 degrees C. In the 6th period. Interpretation: This research will help to understand the relationship between the changes in survival rate, the growth of juvenile A. vulgaris to changing oceanic temperature. The following research will present a strategy to maintain the population of A. vulgaris by using shorter cycle, where it participates in reproduction at lower temperature or delay the growth for increasing survival ratio.