Larval development of two pinnotherid crabs, Asthenognathus inaequipes Stimpson, 1858 and Tritodynamia rathbunae Shen, 1932 (Crustacea, Brachyura), under laboratory conditions

The morphological features of laboratory-reared larvae of Asthenognathus inaequipes and Tritodynamia rathbunae (family Pinnotheridae) are described and compared to related species. A. inaequipes and T. rathbunae both have five zoea and one megalopa stages. Diagnostic characters relating to distinct setal patterns between the two species are given. For specimens reared in 1989, the second zoea of T. rathbunae had irregular features on the antennae and telson in comparison with the other zoeal stages. However, these features were absent when the zoeae were reared once again in 1996 to confirm this phenomenon. The appendages of the irregular second zoea closely resembled those of the zoea of the family Goneplacidae.