Variations of Reproductive Traits of Two Semi-terrestrial Isopods, Ligia exotica and L. taiwanensis (Crustacea: Ligiidae), in Southern Taiwan

ductive allocation per brood (F1,198 = 706, P < 0.001), weight-specific egg weight (F1,198 = 166, P < 0.001), and weight-specific fecundity (F1,198 = 120, P < 0.001), but they also display similarities in the interrelation­ ships between reproductive traits. The reproductive traits of L. taiwanensis, such as larger weight-specific egg size and lower reproductive allocation, seem more in accordance with theoretical predictions for K-selected traits than those of L. exotica. When the effects of body size are removed, both species show a significant positive correlation between fecundity and brood weight (L. exotica: r = + 0.49, t = 5.50, P < 0.001; L. taiwanensis: r = + 0.96, t = 36.09, P < 0.001), and a negative correlation between fecundity and egg size (L. exotica: r = - 0.77, t = 11.78, P < 0.001; L. taiwanensis: r = - 0.32, t = 3.41, P < 0.001) intraspecifically. The reciprocal rela­ tionships between egg size and fecunidity in L. exotica and L. taiwanensis seem to match the assumption of optimality theories of life-history evolution.