The occurrence of the fiddler crab Minuca brevifrons Stimpson, 1860 in Ecuador (Eloy Alfaro, province of Manabi) is reported for the first time. The organisms had a small patchy distribution sharing habitat in a mangrove area destined for the harvesting of the blue crab Cardisoma crassum Smith, 1870, where they established an inquilinism relationship since it lives in burrows built by the blue crab. The identification of specimens was based on taxonomic characters and bibliographic review, where the distinctive morphological feature is the width of its forehead and the oblique crest on the palm of the greater chela. This record extends its distribution on the Pacific side to Ecuador, contributing to the knowledge of biodiversity at the regional level. It is recommended to increase the studies aimed at the diversity of crustaceans at the local level to understand their biology, dynamics, ...

Over the years, crustaceans have colonized various ecosystems, including the rocky marine intertidal, thanks to their adaptive capacity; however, the lack of information and studies regarding this taxon makes it difficult to know its diversity and the state of its populations. Therefore, the objective was to evaluate the carcinofauna of four rocky beaches that have geomorphological differences in the provinces of Guayas and Santa Elena, Ecuador, including their relationship with physicochemical parameters of the water through an ecological analysis with sampling based on transects and quadrats. The results indicated that these parameters do not affect the distribution and presence of crustaceans, but rather, the structural shape of the beaches, indicating that the most heterogeneous beaches harbor a greater carcinological diversity due to the variety of evolutionary morphological adaptat...

Fiddler crabs are the most representative brachyurans in estuaries; they are within the Ocypodidae family where males present strong sexual dimorphism due to a process called hetero-chelation, they also have a great adaptive capacity from their larval stage, so studies that cover part of the development of these organisms are necessary, Uca ornata (Smith, 1870) is a crab that has few ecological and taxonomic studies and the larval description is a fi rst step, for this, U. ornata larvae obtained in captivity were analyzed, where diagrams of the fi rst larval stage were made, including a description of the relevant taxonomic characteristics with the aid of optical microscopy and microscope camera. Th e results were compared with other species of fi ddler crabs of the same genus, fi nding that these characteristics allow these species to be diff erentiated even if they are from diff erent ...

The polychaete Notopygos ornata (Grube, 1856) is recorded for the first time in continental Ecuador, the species is distributed from the Gulf of California to the Galapagos Islands. Its identification was based on specialized literature, taxonomic keys and original description. The main characteristic of this specie is its three-lobed caruncle, the complex pigmentation pattern that starts from chaetiger 7 in the dorsal region and the anus in a dorsal position in chaetiger 24. The present work confirms that its distribution extends on the Pacific side of the Ecuadorian continent, it is suggested to carry out more research on the polychaetofauna that exists in the country.