Abstract.This study is based on a description of the anatomical development of live eggs and larval characteristics of queen conch,Strombus gigasL., before hatching, and the development of these characteristics at five different temperatures (24°C, 26°C, 28°C, 30°C and 32°C). The effect of temperature was quantified with reference to six easily identifiable morphological changes, selected from 27 identified characteristics. The relationship between the appearance of the six characteristics and water temperature was used to calculate the minimal biological temperature (MBT) for queen conch. The “degree days” for each characteristic until hatching were determined. These data can be used to predict ihc hatching time at predetermined temperatures in culture systems. The work also has the benefit of providing synchronously developed material for S. gigas for developmental, biological, physiological and biochemical research of this