Acta Zoologica. 2020;00:1–10. wileyonlinelibrary.com/journal/azo | 1 © 2020 The Royal Swedish Academy of Sciences 1 | INTRODUCTION The tidal spray crab Plagusia depressa (Fabricius, 1775), usu- ally found in the western Atlantic (North and South Carolina, Florida, Gulf of Mexico, Antilles and Brazil—Fernando de Noronha Archipelago, Rocas Atoll, Saint Peter and Saint Paul Archipelago, Trindade Island and from Ceará to Bahia) and the Eastern Atlantic (Azores, Madeira and Senegal to Angola), inhabits crevices of rocks and corals, tide pools, in- tertidal or in port areas (Melo, 1996; Williams, 1984). It is a very agile animal, but easily caught on the reefs at night using light attraction (Freitas & Santos, 2002). The crabs of the genus Plagusia can be often seen clinging on drifting debris, buoys, oil rigs and ship hulls (Alcock, 1900; Dawson, 1987; Farrapeira, Melo, Barbosa, & Silva, 2007; Rathbun, 1918). This behaviour allows their distribution over long distances and exposes them to anthropogenic interventions (Garth, 1966; Carlton, 1987). Plagusia depressa has hard-shell mating, and it is not re- quired for females to moult (McLay & Sal Moyano, 2016). This crab is known to present a continuous reproductive pe- riod, normally with peaks in the middle of the year (Freitas & Santos, 2002; Coelho et al., 2004; Freitas & Santos, 2007; Rocha, de Lira, Santana, Guimarães, & Calado, 2019). The Received: 28 March 2020 | Revised: 9 May 2020 | Accepted: 11 May 2020 DOI: 10.1111/azo.12337 REVIEW ARTICLE Gonad development in mature females of tidal spray crab Plagusia depressa (BRACHYURA: PLAGUSIIDAE) Marcio Paiva Guimarães | Tereza Cristina dos Santos Calado | Matheus Souza Ferreira de Barros Setor de Carcinologia dos Laboratórios Integrados de Ciências do Mar e Naturais (LABMAR), Universidade Federal de Alagoas (UFAL), Maceió, Brazil Correspondence Matheus Souza Ferreira de Barros, Setor de Carcinologia dos Laboratórios Integrados de Ciências do Mar e Naturais (LABMAR), Universidade Federal de Alagoas (UFAL), Rua Aristeu de Andrade, 452, Farol, Maceió, Brazil. Email: matheus.barrosteu@gmail.com Abstract Information on crustacean ovary development is important to properly understand many life story traits. This study aimed to describe macroscopic and microscopic stages of gonad development in females of Plagusia depressa (Fabricius, 1775). Thirty females of P. depressa were captured manually and underwent analgesia by decreasing temperature to collect the gonads, which underwent standard histologi- cal techniques. The macroscopic and microscopic appearance of the ovaries and the frequency of germ cells and their location in the organ were used to determine the stage of gonadal development. A total of four stages were defined. Stage 1: marks the end and beginning of gonadal maturation cycle. The germinal zone is tightly reduced with few oogonia and pre-vitellogenic oocytes are rarely observed. Stage 2: yellow to orange colour and firm consistency. Oogonias and pre-vitellogenic oocytes can be observed at this stage, as well as a few vitellogenic oocytes at organ limits. Stage 3: colour between red and dark brown. The gonad already presents many mature oo- cytes. Stage 4: characterized by the abundance of mature oocytes that occupy almost the entire organ. Macroscopic appearance of the female reproductive system, cell characteristics and changes during maturation of P. depressa corroborate with the normally found in Malacostraca. KEYWORDS Crustacea, Decapoda, histology, morphology, Plagusiidae, reproduction