The taxonomy of the western Indian Ocean pilumnid crab, Pilumnopeus convexas (Maccagno, 1936) (type locality: Ethiopia) is discussed and the poorly known P. salomonensis Ward, 1942

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Crinoidea is the class of marine animals composed of crinoids, which comprises the feather-stars or sea-lilies. Vast arrays of living and extinct species are found in shallow water to great depths in this most primitive of living classes of Echinodermata (Pandian, 2018). Many species of stalked crinoids live in deep seas and a few are sessile, which are exhibited on rocky beaches. There are a variety of colors, from the most vibrant animals to the pale or colorless. Only the genus Comanthus A.H.Clark, 1908 is found in Pakistani waters. Presently we described the taxonomy of shallow-water Comanthus wahlbergii (Müller, 1843) that were collected from Jiwani (Pakistan) (25°03'06''N 61°44'35''E).

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The decapod fauna in the intertidal zone of the rocky shores of Chile is highly diverse, especially along the northern and central mainland coasts, where the influence of the cold Humboldt Current results in high productivity. One of the most abundant species in these ecosystems is the decapod Cyclograpsus cinereus Dana, 1851. The aim of the present study, carried out in the spring and summer seasons between 2018 and 2020, was to determine the spatial distribution patterns of the decapod C. cinereus in different sites along the rocky shores of Antofagasta bay, northern Chile, in order to establish probabilistic models that explain its distribution at each site. Individuals were counted in random quadrants in the intertidal zone. The data thus obtained were processed by application of the variance/mean ratio to determine whether the distribution of individuals was random, aggregated or uniform, associated with Poisson, negative binomial or positive binomial distributions, respectively. The data revealed aggregated (negative binomial) distribution in 15 sampling events, and uniform (positive binomial) distribution in 4 events. The sampling sites were located on rocky shores in four sectors of an urban zone, and two in a protected zone; no significant differences were found between the densities of the sites in the two zones. The results of the interpretative probabilistic models indicated aggregated distribution patterns, agreeing with previously reported interpretative probabilistic models for the distribution of decapods on the rocky shores of central and southern Chile.