Abstract
Using allometric growth analyses, we investigated the sexual size dimorphisms of the pleons and chelipeds of the varunid crab Gaetice depressus, wherein the carapace width (CW) values for females and males were 4.11–21.22 and 4.01–27.68 mm, respectively. Pleons were larger in females, which showed positive allometric growth, than in males, where negative allometric growth was observed. In females, three distinct groups based on pleon size were identified: small-sized individuals with <4.11–9.05 mm CW and narrow pleons, medium-sized individuals with 10.39–10.71 mm CW and intermediate-sized pleons, and large-sized individuals with >10.52–21.22 mm CW and wide pleons. These three groups correspond to the following classification: immature, subadult and mature crabs. As for the chelipeds, the females showed positive allometric growth or isometric growth across body sizes. In males, the isomeric growth in cheliped propodus length and merus length shifted to a positive allometric growth at 9.62–10.58 mm CW, whereas the cheliped propodus width showed positive allometric growth across body sizes. Overall, male chelipeds showed stronger positive allometric growth than the female chelipeds, and the sexual size dimorphism of chelipeds was evident after ~10–11 mm CW was reached, during which morphological sexual maturity may occur.
https://ror.org/048nxq511 
