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From Ovledo to Rathbun: The development of brachyuran crab taxonomy in the Nootropics (1535–1937)
Published in Frank Truesdale, History of Carcinology, 2020
The main reason for taxonomic uncertainty in the Trichodactylidae and the Pseudothelphusidae is that in most cases the only specific diagnostic characters are found in the first male gonopod, an appendage disregarded by all the early taxonomists except Rathbun who recognized its significance In brachyuran systematlcs. In her monograph (Rathbun 1905,1906) she illustrated first male gonopods of 17 pseudothelphusids; however, she ignored the gonopod in describing the remainder of pseudothelphusids and in describing all trichodactylids. In fact, she used female holotypes for several of her new species. After her mongraph, Rathbun described nine additional pseudothelphusids (1912, 1915a, 1919, 1933c); six ofthese are considered valid today.
Scylla Sp. Shell: a potential green adsorbent for wastewater treatment
Published in Toxin Reviews, 2022
Azrul Nurfaiz Mohd Faizal, Nicky Rahmana Putra, Muhammad Abbas Ahmad Zaini
The mature and immature Scylla sp. have different abdomen shapes. The immature female has a triangular-shaped abdomen while for the mature one has a broader and semi-circular abdomen shape. For male, there is no difference in abdominal shape or size for either mature or immature, both exhibit a T-shaped abdomen. The mature male endows bigger chelipeds than the female of the same carapace size (Quinitio and Parado-Estepa 2003). The male crab has two pairs of modified pleopods (gonopods), where the ejaculatory ducts located, while the female crab uses pleopods for egg brooding and has a pair of vulvae located on the sixth thoracic segments. The locking mechanism helps the crabs keep their abdominal flap in place. Figure 2(b,c) shows the modified pleopods of male and the vulva of female crabs.