Morphological changes during ontogeny of the male first and second gonopods of Mithraculus forceps A. Milne-Edwards, 1875 (Brachyura: Majoidea: Mithracidae)

Author(s)

Mollemberg, Michelle ^[1] ; Lianos, Laira ^[1] ; Zara, Fernando Jose ^[2] ; Swenson, Rafael ^[3] ; Cobo, Valter Jose ^[4] ; Santana, William ^{[1, 5]}

Affiliation

^[1] Univ Estadual Paulista, Lab Sistemat Zool, Botucatu, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Sch Agr & Vet Sci, Dept Appl Biol, Invertebrate Morphol Lab IML, Jaboticabal - Brazil

^[3] Unisagrado, Ctr Ciencias Saude, Bauru, SP - Brazil

^[4] Inst Basico Biociencias Taubate UNITAU, Lab Biol Marinha, LabBMar, Taubate, SP - Brazil

^[5] Univ Reg Cariri URCA, Dept Biol Sci, Crato - Brazil

• Document type: Journal article
• Source: Journal of Natural History; v. 55, n. 15-16, p. 953-967, APR 18 2021.
• Web of Science Citations: 0

Abstract

In brachyuran crabs, the complexity of the copulatory system provides important information about the systematics of the group. Here we used scanning electron microscopy and light microscopy to provide information about the morphological changes during the gonopods ontogeny in the spider crab Mithraculus forceps. For this, a series of specimens were analysed and grouped in size classes of cephalothorax width (CW). The smaller males (first and second size classes) presented the first gonopod without a formed ejaculatory aperture and with an indistinct apical plate. The ejaculatory canal aperture is fully formed in size class 5 with 8.8 to 9.9 mm (CW). In adult males, the apical plate is divided in two lobes: a rounded mesial lobe and a distinct tapering lateral lobe with a large ejaculatory canal aperture. Throughout growth, there was an increment in number and/or size of the secondary cuticle structures, such as setae, spines, and sensilla. Morphological changes in the second gonopod are not abrupt during the ontogenetic development, with the girdle in the apical region and the median process becoming more prominent and tapered. Although to clearly determine the sexual maturity, information on the gonadal development (physiological sexual maturation) is needed, we observed that the gonopods morphology could provide important information to determine the sexual maturation. In our analyses, the morphological maturity occurred in line with the physiological maturity, both diagnosed in the size class 5. (AU)

• FAPESP's process: 13/01201-0 - Biodiversity and endemic patterns of Majoidea (Crustacea, Decapoda, Brachyura) in Brazil
• Grantee: William Ricardo Amancio Santana
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 18/13685-5 - Integrative analysis of the Brazilian fauna of decapod crustaceans: taxonomy, phylogenetic systematics, spermiotaxonomy, morphology of post-embryonic development, ecology and conservation
• Grantee: Fernando Luis Medina Mantelatto
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants