Apseudes sp.

Kakui, Keiichi & Hiruta, Chizue, 2023, Differential masculinization of the chelipeds in two simultaneously hermaphroditic Apseudes tanaidaceans (Crustacea: Malacostraca), Zoologischer Anzeiger 305, pp. 23-27 : 24

3.2. Apseudes sp.

All individuals we observed bore a genital cone on the ventral surface of pereonite 6. Ranges in CW were 0.56–0.99 mm (ln CW, 0.05 to 0.01) for oostegite-lacking individuals, 1.04–1.47 mm (ln CW, 0.04–0.39) for preparatory individuals, and 1.17–1.53 mm (ln CW, 0.16–0.43) for ovigerous individuals ( Fig. 2I–L ).

The size increase in CarW and CheW relative to CW was monophasic; no breakpoints were detected. The respective regressions were ln CarW =1.197 (ln CW) – 1.815 (R 2 =0.987) and ln CheW = 1.092 (ln CW) – 1.664 (R 2 = 0.983).

Individuals 0.56–1.19 mm in CW (ln CW, 0.57 to 0.18) bore no dorsal process on the fixed finger, whereas individuals 1.17–1.53 mm in CW (ln CW, 0.16–0.4) bore a process ( Fig. 2K, L, N, P ); the size of process was generally smaller in smaller individuals. The ventral margin of the carpus was smooth in all individuals ( Fig. 2M, O ).

Figures

Fig. 2. Masculinization of chelipeds in A. nipponicus and Apseudes sp. A–H, A. nipponicus; I–P, Apseudes sp. Relationships between chelipedal carpus width and carapace width after log-transformation (A, C, I, K). Relationships between chela width and carapace width after log-transformation (B, D, J, L). Lateral views of chelipedal carpi and chelae in small individuals (E, F, M, N) and large individuals (G, H, O, P). Arrowheads, processes. Abbreviations: Ap, individual without processes on fixed finger and chelipedal carpus; CarW, chelipedal carpus width; CheW, chela width; CW, carapace width; OL, individual lacking oostegite; Ovi, ovigerous individual; Ppf, individual with process on fixed finger; Ppfc, individual with fixed finger and chelipedal carpus bearing one and four processes, respectively; Pr, preparatory individual.