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Shane T. Ahyong

Abstract

A new species of Viridotheres is described from material in the collections of the Museum für Naturkunde, Berlin, representing the first record of the genus from Indonesia. The new species most closely resembles V. takedai Ahyong, Komai & Watanabe, 2012 from Japan, and, significantly, shares the well-developed G2 exopod. Males of a second species of pinnotherid crab in the Berlin collection, misidentified as Ostracotheres tridacnae (Rüppell, 1830), proved referable to Afropinnotheres dofleini (Lenz in Lenz & Strunck, 1914), from South Africa, for which only females were known in detail. The male of A. dofleini is redescribed and figured in detail for the first time. Notably, males of A. dofleini also have a gonopod 2 exopod, the first such report for the genus. Confirmation of the gonopod 2 exopod in A. dofleini and V. kupang sp. nov. highlights the increasing significance of the gonopod 2 exopod in pinnotherid systematics and morphology.

Patricio De los Ríos and Eriko Carreño

Abstract

The crustacean zooplankton in Chilean coastal lagoons has been poorly studied as yet, and the scarce studies available would indicate the presence of low species numbers that vary as a function of the trophic status of the water bodies. The aim of the present study is to make a first characterization of crustaceans in a small shallow coastal lake, using null models, specifically with regard to species co-occurrence and niche overlap. The results revealed that the species associations we found are random, which is due to many species that occur in most or all of the water bodies examined, whereas niche sharing revealed that there is niche segregation due to the absence of competition among the species reported. These results would be in agreement with observations for mountain lakes and lagoons in northern Patagonia, both in Argentina and in Chile, and partially similar to what has been found in Andean shallow wetlands in northern Chile. More and more detailed studies will be necessary for understanding the population and community dynamics in these water bodies.

Masayuki Osawa and Takuo Higashiji

Abstract

Propagurus haigae (McLaughlin, 1997), a relatively large-sized species of Paguridae, is reported for the first time from Japanese waters based on a single specimen collected from a depth of 620 m off Ie Island, central Ryukyu Islands, southwestern Japan. It is the third species of the genus Propagurus McLaughlin & de Saint Laurent, 1998 known from Japanese waters. The present specimen greatly extends the distribution range of P. haigae, because the previous northernmost record was the Molucca Sea in Indonesia.

Sang-Hui Lee, Sang-Kyu Lee, Sa Heung Kim and Won Kim

Abstract

Two galatheids, Allogalathea elegans (Adams & White, 1848) and Phylladiorhynchus pusillus (Henderson, 1885), are newly reported from Korean waters in material from around Jeju Island. The two genera, Allogalathea Baba, 1969 and Phylladiorhynchus Baba, 1969 are also reported from Korea for the first time. Now, the known Korean galatheids consist of six species belonging to three genera. Illustrations and diagnostic descriptions of the two newly recorded species are given herein.

Raquel A. Moreira, Eneida M. Eskinazi-Sant’Anna and Daniel Previattelli

Abstract

A new species of harpacticoid copepod, genus Forficatocaris (F. odeteae n. sp.) is described from a high-altitude pond at the Itacolomi National Park near Ouro Preto city, Minas Gerais state, Brazil. The main characters distinguishing the new species from F. affinis Dussart, 1983 and F. lilianae Noodt, 1972 are: (i) distal portion of exopod 1 of male leg 4 with stout spinules; (ii) male leg 5 lateral spine stout and with blunt apex; (iii) endopod of leg 4 curved outwards, but “c” shaped (not forming a straight angle); (iv) female with dorsal spinule row on anal somite larger than in congeners, ventral ornaments smaller and less numerous; and (v) the shape of the modified spine located at the leg 1 endopod 1 of the male; and (vi) the spine of leg 5 in males and females.

Bianca L. Zimmermann, Jober V. De Vargas Machado, Sandro Santos and Marlise L. Bartholomei-Santos

Abstract

Representatives of the genus Aegla present a conserved morphology; thus, the increased use of molecular markers has raised many taxonomic issues. We used AFLP and mtDNA to investigate the genetic differentiation and phylogenetic relationships of morphologically similar species with overlapping distribution areas in southern Brazil: A. georginae, A. ludwigi, and A. platensis. While A. platensis is widely distributed, the critically endangered A. georginae and A. ludwigi have limited distributions. Although both markers showed populations with low levels of genetic variability, they differed markedly in revealing relationships between populations; according to AFLP, the genetic distances between A. platensis populations were as high as those between distinct species, a result not observed when considering mtDNA data. We emphasize that the use of multiple lines of evidence is necessary for defining correct levels of genetic diversity and a good species-level taxonomic resolution. Such features are essential for the management and conservation of Aegla species.

Orlando Lam-Gordillo and Pedro-Luis Ardisson

Abstract

The study of species distributions is fundamental for environmental research, conservation planning, and resource management. However, it is not always possible to obtain access to these data, making it difficult to reach the goal of quantifying biodiversity. The distribution of many crustacean groups is poorly studied; such is the case of the superfamily Raninoidea (frog crabs). In order to reduce this information gap, herein we mapped and described the world distribution of members of this superfamily by performing a data visualization analysis. We carried out an extensive review of species records and distribution data from different databases, collections, and unpublished data. Furthermore, we conducted a species richness analysis and an agglomerative cluster analysis to identify biogeographic regions. Both analyses were carried out using the software Biodiverse (v. 2.0). Results showed that Raninoidea is composed of 46 species across a pantropical distribution. For this study, the globe was divided into 30 pre-established biogeographical regions, ranging from the Indo-Pacific seas & Indian Ocean (IPSIO) region, represented by 19 species and a maximum richness of eight species, to the Southern Ocean (SO) region, represented by only one species. Some species are distributed across regions while some are found exclusively in a single region. Due to issues with accuracy and sufficiency of raw data, we also calculated the Chao 1 and ACE indices, which suggest that other species have yet to be recorded.

Takeru Nakamachi and Akira Asakura

Abstract

Intertidal isopods use a variety of living or non-living objects as habitats, although only a few studies have been made on their ecological function and significance. In the present study, the habitat utilization by the sphaeromatid isopod, Dynoides dentisinus was recorded based on observations on intertidal rocky shores in the warm temperate zone of Japan during the period from 2014 to 2018. The adults of this species have a remarkable sexual dimorphism in the morphology of their armature: adult males possess an elongate pleonal process, like a large horn, on the dorsal side of the pleon and have large uropods. On the other hand, females do not have such a horn, and the uropods are small. Differences in habitat use were seen according to the stage in the life history of the species. Juveniles lived on, or amongst, algae and were sometimes associated with molluscs such as chitons, limpets and whelks. Adults inhabited the cryptic habitats such as gaps in algal holdfasts, oscula of demosponges, dead barnacle shells, cavities of dead corals, and crevices in sand rocks. Generally, a single adult male was present in each cryptic habitat, keeping head in down position, and one or more females cohabited inside with the male. These suggest that D. dentisinus has a biphasic life history; juveniles live and feed on algal cover or use the spaces between the ventral sides of the molluscs and the surfaces of the rocks as a refuge from desiccation. Adults breed in the cryptic habitats, forming a polygynous group.

José E. Martinelli Filho, Thuareag M. Trindade Dos Santos, Marcelo Petracco, Renata C. De Lima-Gomes and Célio U. Magalhães

Abstract

Crabs of the family Pseudothelphusidae are restricted to the Neotropical region and new species are described every year. They are threatened by habitat loss and knowledge of this family is almost limited to taxonomy and faunal surveys. Here, we investigate the presence of heterochely and laterality in Kingsleya castrensis, as a tool to infer ecological and behavioural aspects. Since most Pseudothelphusidae were described from a few individuals only, some aspects of morphological variation, sexual dimorphism, heterochely and laterality are confirmed herein for the first time for a species of Kingsleya. The sizes of dactylus and propodus of males, as well as the allometric growth of both sides of the chelipeds, were significantly larger and higher, respectively, when compared to females. The right side was significantly longer than the left and both sexes displayed right-handedness. These results are similar to those from other freshwater crab families, and provide a clue to a possible aggressive, display, and territorial behaviour in K. castrensis.