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Snorre Bakke, Lene Buhl-Mortensen and Pål Buhl-Mortensen

Abstract

Available species information pages and fact sheets define 100 to 200 m as the maximum depth of occurrence for Cancer pagurus. We here present some observations from video transects conducted in Sognesjøen, Norway, where numerous individuals of adult C. pagurus were observed at more than 400 m depth. Within the area investigated, 81 live crabs, 3 dead crabs/exuviae, and 32 areas with concentrated shell remnants were counted. In addition, several areas were covered with obvious crawling tracks from crabs. Spatial variation in the density of live crabs, remnants, and tracks varied between 0 and 52 crabs/100 m2. Size estimations based on 19 individuals showed an average carapace width of 14.5 cm. Possible explanations for why the crabs are present at these depths, are discussed.

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Kunihiko Izawa

Abstract

Lernaeenicus ramosus Kirtisinghe, 1956 is redescribed on the basis of metamorphosed females recovered from the body surface of Epinephelus akaara (Temminck & Schlegel, 1842) (Pisces, Serranidae). Also the male, copepodid I, both sexes of chalimus II and III, and chalimus IV male were recovered, together with the females, from the branchial lamellae of the same host and are herein described for the first time for the species. The developmental process of leg 4 in L. ramosus differs from that in L. sprattae (Sowerby, 1806).

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Benoit Gouillieux

Abstract

Hermit crabs are well-known to shelter many epibiotic, endobiotic or endolithic species in their shell, and examination of shells inhabited by hermit crabs in Arcachon Bay reveals the presence of several such species. Among them is the amphipod Monocorophium acherusicum, a species originally described from European waters and now known to be well distributed throughout the world, but not previously recorded to be commensal with hermit crabs, as reported herein.

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Arshad Keethadath, Sudha Kappalli, N. Gayathri, Derin M. Thomas and Gopinathan Anilkumar

Abstract

Radiopreservation using gamma radiation is widely in use as a safe method for extending the shelf life of shellfish. This study explored the consequences of different doses of gamma radiation (0.5 kGy, 1.0 kGy and 2.0 kGy) on various tissues of Scylla serrata at cellular and nuclear level, with the aid of electron microscopy and DNA comet assay. The highly radio exposed (2.0 kGy) pyloric muscles showed a reduction in sarcomere length, disordered organization with expanded gap between adjacent myofibrils, ruptured sarcotubular system, mitochondrial swelling with crushed cristae, significant increase in nucleus size coupled with less dense nucleoplasm, etc. Comet assay on tissues such as muscle, hepatopancreas and testis irradiated with 2.0 kGy radiation also revealed a significant degree of nuclear damage by gamma irradiation in a dose-dependent manner. The tail length of the comet showed a tissue-specific tolerance level. The present study clarified the precise dose of irradiation as 1.0 kGy and the results can be relevant for commercial purposes to qualitatively categorize the irradiated crabs.

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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.

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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.

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Patricio De los Ríos, Jaime Pizarro-Araya, Fermín M. Alfaro and Carlos Zuleta

Abstract

The crustacean communities in Chilean seasonal pools have been poorly studied, and much of the existing literature is restricted to southern Patagonian plains, whereas there are no studies available about other sites. The aim of the present study is to describe the aquatic crustaceans in shallow pools in Huentelauquén (31°S, central northern Chile). The species reported upon include Daphnia ambigua, Simocephalus serrulatus, Boeckella gracilipes, Ostracoda, and two unidentified clam shrimps (genera Lynceus and Leptestheria), which latter ones represent the first record of these taxa for Chile. The ecological results revealed low species numbers and non-structured patterns in the various species associations. The exposed results are markedly different from observations on other Chilean seasonal pools, where no clam shrimps can be found, and where primarily cladocerans, copepods, and amphipods occur in the crustacean communities.

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Selmeg V. Bazarsadueva, Larisa D. Radnaeva and Arnold K. Tulokhonov

Abstract

In this report, we have compared the fatty acid composition of the endemic Lake Baikal amphipods Ommatogammarus albinus (Dybowsky, 1874) and Parapallasea lagowskii (Dybowsky, 1874). Specimens were sampled using the deep-water manned submersible “Mir” at the oil-methane seeps of Cape Gorevoy Utes and at a hydrothermal vent in Frolikha Bay. High levels of monounsaturated fatty acids and relatively low levels of saturated and polyunsaturated fatty acids were detected in the studied amphipods, with oleic and palmitic acid representing the main fatty acid components. The habitat of the amphipods exerted a profound effect on their fatty acid profile: the amphipods of Gorevoy Utes contained higher levels of linolenic 18:3n3 and arachidonic 20:4n6 acids, while the amphipods of Frolikha Bay contained higher levels of eicosapentaenoic 20:5n3 and docosahexaenoic 22:6n3 acid. Based on these findings, we suggest that the amphipods’ diet in different areas of Lake Baikal determines their fatty acid composition.

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Jian Hua Chen, Meng Jie Wang, Xue Li, Hai Hua Wang, Huan Gao and Bin Lun Yan

Abstract

Wnt4 (Wingless-type MMTV integration site family member 4) has been demonstrated to play critical roles in a wide variety of biological processes, including embryonic development, cell proliferation, and differentiation in vertebrates, but its function in crustaceans is still not clear. In the present study, the full-length wnt4 cDNA sequence was cloned and characterized for the ridgetail white prawn Exopalaemon carinicauda. The expression patterns of the wnt4 mRNA in embryos and larvae at different stages were investigated. The tissue distribution showed that wnt4 was obviously expressed in eyestalk and hepatopancreas. During embryonic development, the wnt4 was highly expressed in all developmental stages except the zygote, two-cell stage, and late zoaea stage. The wnt4 mRNA was expressed in Z1-Z5 and post-larval stages. Taken together, the present study indicates that the wnt4 gene may be involved in the regulation of embryonic and larval development in the ridgetail white prawn.

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Series:

Edited by Charles Fransen

This volume is dedicated to the memory of the eminent carcinologist Michael Türkay, of the Research Institute and Natural History Museum Senckenberg, Frankfurt am Main, Germany. It is a tribute to his outstanding international contribution to the study of decapod crustaceans. An extensive account of Michael’s life and achievements is presented, along with thirty-one scientific papers by 62 of his friends and colleagues from around the world. The book’s focus is almost entirely on decapod crustaceans, and covers a variety of topics, including taxonomy, systematics, zoogeography, morphology, palaeontology, genetics, general biology and ecology. Numerous new taxa are described from a number of marine and freshwater groups, including one new genus and 13 new species named in honour of Michael himself.

The contents of this volume were originally published in 2017 in Crustaceana volume 90, issue 7-10.